Category: Biology
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Pioneer Species: Definition, Types, and Examples
Continue ReadingPioneer Species Definition
Pioneer Species are those organisms that begin the formation of an ecological community in a region where no living forms currently exist.
What is a Pioneer Species?
Areas that are completely barren, devoid of nutrients, and inhospitable provide slim (to none) possibilities for any living form to establish itself. But to the rescue comes the resilient, photosynthetic, widespread, fast-reproducing, orthodox-seeded pioneer community, with high dispersibility rates, shorter life cycles, and great tolerance…
So, if someone asks us to describe pioneer species, we can quickly describe their basic characteristics and explain how ecological succession occurs.
In primary succession, pioneer species are the first to colonise a bare substrate, whereas in secondary succession, they are the first to colonise a devastated environment.
Examples include
(1) a pioneer lyme grass (Leymus arenarius) on a sand-covered plain,
(2) pioneer plant species (e.g. swordfern, Polystichum munitum, and the moss Racomitrium ericoides) that thrived in a newly formed habitat created by a solidified lava flow, and
(3) pioneer plant species that colonised an area that had been cleared.
Pioneer Species Example
A thorough collection of instances has been compiled. To learn more about them, look at the image below. Pioneer germs, fungi, and animals only enter when pioneer flora and lichens have mastered their tasks. Soil invertebrates such as ants, worms, and snails, as well as some toads, are examples of pioneer fauna.
The Sword Fern (Polystichum munitum) is a Pteridophyta pioneer.
Features of Pioneer Species
1. Hardy in nature: Pioneer species are able to endure and trade in a variety of severe environmental circumstances.
2. Seeds- Orthodox and easy to germinate: Pioneer species have orthodox seeds, which are “seeds with less than 5% total moisture content that are nonetheless alive and have remarkable longevity.” This property aids pioneer species in reproducing even after years of hibernation. Desiccation is not a problem for them, and they may produce new plants following germination. These seeds are unaffected by low moisture content.
3. Seed Germination- Light-Induced: The seeds of pioneer species are often “photoblastic,” meaning they germinate when light is stimulated. Any seed will germinate if it is given ideal moisture, nutritional, and other environmental circumstances, but these seeds don’t have much demand in desolate regions. Their only requirement for germination has evolved to be “light stimulation.”
4. Life Cycle- Short: Any biological body is created with the ultimate goal of “species perpetuation” in mind. Pioneer species have evolved to have a brief life cycle since desolate environments give little opportunity for any creature to enjoy a happy time for a long time. This is a sign that they are in the early stages of their reproductive lives. Pioneer species reach reproductive maturity quickly, regardless of how they generate progeny (sexual or asexual).
5. Pollination and Seed Dispersal- Both via wind: In the same way that an unfriendly habitat is bad for any species, it is also bad for pollinators (whether they are birds, insects, bats, or animals). Wind pollination is the only viable option. The majority of sexually reproducing pioneer species, for whom pollination is an important stage in gamete fertilisation, are pollinated by the wind. Furthermore, the wind is used to disperse their seeds.
6. Rates of Seed Production and Dispersal- High: Pioneer species’ seeds are extremely viable, generated in a geometric pattern (in huge numbers), and have a high dispersion rate. Such dispersion rates are required to colonise a nutrient-deficient terrain.
7. Propagule Size- Small: Small propagules make it easier to disperse and achieve succession goals. Small seed or propagule size also enhances germination chances since they can get “caught” in small cracks, holes, and traps during hostile periods.
8. Wide Range- Both ecological and geographical: This broadens the distribution and helps primary succession in regions impacted by a variety of causes.
9. Major Mode of Reproduction- Asexual > Sexual: Because sexual reproduction is more energy-intensive and time-consuming, it isn’t truly a viable option for pioneer species. Although there are certain animals that have a sexual mode. The asexual mode, on the other hand, is more popular due to the benefits it provides.
Certain lichens and algae are widespread species that can thrive in a variety of environments, making them the most common pioneer species, or initial settlers, after a disturbance. Because the new environment is likely to have soil with fewer nutrients and be primarily exposed to light energy, the pioneer plant species are often photosynthetic.
It’s also more likely that wind pollination is used by pioneer plant species. Furthermore, rather than sexual reproduction, most people reproduce asexually. The pioneer species may eventually give nutrients to the soil, resulting in a better environment for the following species.
Pioneer Species and Ecological Succession
It is critical to comprehend ecological systems, the formation of ecological communities, and ecological successions in order to create conceptual clarity about pioneer species. The biological interactions between the many parts of the natural system, as well as their various interrelationships, are referred to as ecological systems.
The way an ecological system is constructed influences how it will work, as well as its fundamental requirements, long-term viability, and success. An ecological community is based on how “often” certain species occur together in a given region.
The species share comparable environmental conditions and resource scarcity/abundance. The community’s equilibrium is determined by how they affect one another. All variables, processes, and interrelationships within a community that regulate its evolution across time are referred to as ecological succession. It is primarily concerned with the “structural” evolution of a biological community through time.
Every physical, chemical, and biological entity changes over time, and ecological succession describes these changes. “Changes in community skeleton” – how different species evolve, how one’s evolution affects another’s, how coevolution occurs, and how organisms gradually adapt to thrive in harsh environments.
Types of Ecological Successions
i. Primary Succession
Primary succession occurs when an organism lives, thrives, and reproduces in a region where no other organism has ever lived, flourished, or reproduced.
Only pioneer creatures, especially “only pioneer plants,” can lead to the establishment of a friendly habitat in this case. Characteristics of every pioneer organism capable of bringing about primary succession:
1. Any barren area would be devoid of pre-existing organic compounds, making organic compound oxidation for energy purposes impossible.
2. Because there are no pre-existing autotrophs on barren ground, the heterotrophic mechanism of carbon derivation is clearly removed.
3. Any desolate terrain would almost certainly lack any biological source of electrons (even inorganic ones are unlikely… But if some minuscule probability is included, it’s still only an inorganic source!).
As a result, in primary succession, the pioneer species must be a plant—a photo-auto-lithotroph. They colonise bare surfaces (without soil) and then form ecological communities.
Primary Succession Examples
Photo-auto-lithotrophs include only plants and a specific type of algae known as “blue green algae/Cyanobacteria.” As a result, they are the only pioneer species responsible for initial succession. Apocalyptic habitat loss occurs in areas impacted by large landslides, fires, volcanic eruptions, or flooding. The topsoil and layers underneath it are eroding in certain locations.
There is no energy/carbon/electron source remaining in such regions that can support life other than photo-auto-lithotrophic life. Another aspect worth mentioning is the “essence of a finite resource-NITROGEN.” As a result, several of these pioneers fixed nitrogen.
Because they are photo-auto-lithotrophic and nitrogen-fixing, cyanobacteria are primarily responsible for primary succession in the most severe environments.
Lichens are the first species to appear in primary succession, and they have the unique ability to colonise bare rocky surfaces.
ii. Secondary Succession
Unlike the barren and previously deserted places, certain areas require re-establishment following a disturbance that “wiped away” a full-fledged natural population. The secondary succession is this re-establishment. Some soil and previously existing plants are still present in these locations. There are fewer resource battles in these regions, and pioneer species have an advantage.
We can list angiosperm trees and shrubs as pioneer species in secondary succession if requested. These have some of the highest growth and community development rates in the country. Pioneer species in secondary succession are not required to be photo-auto-lithotrophic.
Secondary Succession Example
Microbial and invertebrate taxa have just recently been added to the pioneer species list. Photo/chemo, auto/hetero, litho/organo trophs are all possibilities. This emphasises an essential point: secondary succession occurs in areas where certain nutrients are already present in the substrate.
Secondary succession occurs in places like deforested regions, logged woods, wind-affected areas, and so on. As a result, numerous microbiological species (bacteria, archaea), invertebrates, and tree species, such as Betula spp. (birch tree species) and Alnus spp. (alder tree species), serve as pioneer species in secondary succession.
An Interesting Fact About Pioneer Species
Did you know that the 1986 Chernobyl Nuclear Power Plant Disaster in Pripyat, Soviet Union, which displaced humans, animals, and other species, gave birth to a new fungus that “feeds on radiation”? Yes… Scientists investigating the region discovered “a pioneer fungus” that is an extremophile suited to strong radiation and has a remarkable capacity to eat it rather than be harmed by it (unlike other organisms).
This fungus species is pushed to the most severe radioactive locations, similar to how plants exhibit phototropism (the ability to be driven towards a light source). This species’ main and secondary metabolic products, which have incredible lytic and enzymatic activity, provide this quality! Who knows how many more pioneer species have been generated and are still being investigated in that catastrophic place… How many more pioneers will be born as a result of this?
Pioneer Species Citations
- How lichens impact on terrestrial community and ecosystem properties. Biol Rev Camb Philos Soc . 2017 Aug;92(3):1720-1738.
- Changes through time: integrating microorganisms into the study of succession. Res Microbiol . 2010 Oct;161(8):635-42.
- Gopher mounds decrease nutrient cycling rates and increase adjacent vegetation in volcanic primary succession. Oecologia . 2014 Dec;176(4):1135-50.
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Null Hypothesis: Definition, Types, and Examples
Continue ReadingNull Hypothesis Definition
The term “null hypothesis” refers to “a generally held belief (such as that the sky is blue) that researchers seek to refute or invalidate.”
A null hypothesis is defined as “a statistical theory proposing that no statistical link exists between given observed variables” in more technical terms.
In biology, the null hypothesis is used to refute or invalidate a widely held view. The researchers conducted the research with the goal of refuting a widely held notion.
A null hypothesis is an assumption or assertion that a difference seen between two samples of a statistical population is attributable to chance rather than systematic reasons. It is the hypothesis that will be tested statistically to see whether it can be rejected, indicating that the alternative hypothesis is correct.
A null hypothesis is one that is valid or believed to be true unless it is disproved by a statistical test. As a result, one cannot state that a null hypothesis is “accepted,” but rather that it “cannot be dismissed,” since statistical evidence supports it.
A null hypothesis that is disproved, on the other hand, is said to have been “rejected.” Ronald Fisher, an English geneticist and statistician, invented the term. H0 is the symbol.
What is Null Hypothesis?
A hypothesis is a theory or supposition that is supported by insufficient evidence. For confirmation, further research and testing are needed. A hypothesis might be incorrect or true depending on how many experiments and tests are conducted. It may either be proven false or true.
Susie, for example, believes that mineral water aids plant development and nutrition more than purified water. She did this experiment for over a month in order to verify her idea. She used mineral water on some plants and distilled water on others.
The hypothesis is called a null hypothesis when there are no statistically significant connections between the two variables. The researchers are attempting to debunk such a theory. The null hypothesis in the following plant example is that there are no statistical correlations between the types of water provided to plants for growth and sustenance.
An investigator often tries to refute the null hypothesis by explaining the relationship or link between the two variables.
The alternative hypothesis is the polar opposite and reversal of the null hypothesis. The alternative hypothesis for plants is that there are statistical correlations between the many types of water that are provided to them for development and sustenance.
The following example illustrates the distinction between null and alternative hypotheses:
1. Alternative hypothesis is that the world is spherical.
2.The globe is not round, according to the null hypothesis.
Copernicus and many other scientists attempted to disprove the null hypothesis. They persuade individuals that alternative ideas are right and true through their studies and tests. People will not accept them unless they can empirically disprove the null hypothesis, and they will never consider the alternative hypothesis true and accurate.
Susie’s alternative and null hypothesis is as follows:
1. Null Hypothesis: There is no difference in the development and sustenance of these two plants if one is watered with distilled water and the other with mineral water.
2. Alternative Hypothesis: If one plant is watered with distilled water and the other is watered with mineral water, the mineral water-watered plant will grow and feed better.
The null hypothesis states that no statistically significant association exists. The relationship might exist between two sets of variables or within a single set of variables.
The null hypothesis is widely accepted as true and correct. Scientists work on many experiments and conduct a range of research in order to disprove or nullify the null hypothesis. They create an alternative hypothesis that they believe is right or true for this reason.
H0 is the symbol for the null hypothesis (it is read as H null or H zero).
This hypothesis is given the label null to clarify and emphasise that scientists are attempting to show it is untrue, i.e., to nullify it. It can sometimes perplex readers; they may misinterpret it and conclude that the sentence has no meaning. It appears to be blank, but it is not. Instead of calling it the null hypothesis, it’s more acceptable to call it a nullifiable hypothesis.
The scientific method is employed in science. It entails a number of distinct phases. These procedures are carried out by scientists in order to determine if a hypothesis is true or incorrect. This is done by scientists to ensure that the new theory will not have any limitations or inadequacies. Experiments are conducted with both alternative and null hypotheses in mind, ensuring that the study is safe.
If a null hypothesis is not included or a part of the investigation, it has a negative as well as a negative influence on the research. It appears that you are not worried about your research and simply want to impose your findings as accurate and true if the null hypothesis is not included in the study.
In statistics, the initial step is to create alternative and null hypotheses based on the problem. The route to a solution is made easier and less hard by breaking the problem down into tiny pieces.
There are two phases to writing a null hypothesis:
1. Begin by posing a hypothetical inquiry.
2. Second, rephrase the question such that there appear to be no connections between the variables.
In other words, make the assumption that the therapy has no impact.
Null Hypothesis Examples
The typical recuperation period following knee surgery is eight weeks. According to one study, if patients go to a physiotherapist for rehabilitation twice a week instead of three times a week, the recovery period will be lengthened.
However, if the patient visits three times for rehabilitation instead of two, the recovery period would be shorter.
STEP 1: Examine the theory for a flaw. The hypothesis might be a phrase or a statement. The hypothesis in the above case is:
“Knee rehabilitation is likely to take more than eight weeks.”
STEP 2: From the hypothesis, formulate a mathematical statement. Because averages may be written as, the null hypothesis formula will be.
H1: μ>8
The hypothesis is identical to H1. The average is indicated by and > that the average is larger than eight in the preceding equation.
STEP 3: Describe what will happen if the hypothesis is incorrect. For example, the rehabilitation time may not last more than eight weeks.
There are two alternatives for recovery: either it will take less than or equal to 8 weeks, or it will take longer than 8 weeks.
H0: μ ≤ 8
The null hypothesis is H0. The average is represented by, and signifies that the average is less than or equal to eight in the preceding equation.
What happens if the scientist doesn't know what the results will be?
Problem: A researcher is studying the impact and influence of extreme exercise on individuals who have had knee surgical operations. The possibilities are that the activity will either help or hurt your recuperation. The average recuperation time is 8 weeks.
STEP 1: Form a null hypothesis, i.e., that the exercise has no impact and that the recuperation time is still almost 8 weeks.
H0: μ = 8
The null hypothesis is identical to H0 in the preceding equation. The average is indicated by, and the equal sign (=) indicates that the average is equal to eight.
Step 2: Create an alternate hypothesis that contradicts the null hypothesis. What will happen, in particular, if therapy (exercise) has an effect?
H1: μ≠8
The alternative hypothesis is equivalent to H1. The average is indicated by, and the not equal sign () indicates that the average is not equal to eight in the preceding equation.
Significance Test
A significance test is used to get a plausible and likely explanation of statistics (data). The null hypothesis is unsupported by evidence. It is a piece of information or a statement that comprises numerical population numbers. The information can be presented in a variety of formats, such as meanings or proportions. It might be an unusual ratio or a discrepancy in proportions and averages.
The P-value is the most important statistical outcome of the null hypothesis significance test.
1. P-value = Pr (data or more extreme data | H0 false)
2. | = “assumed”
3. Pr stands for probability.
4. H0 denotes the null hypothesis.
The formation of an alternative and null hypothesis is the first stage of Null Hypothesis Significance Testing (NHST). The research question may be succinctly described in this way.
1. Null Hypothesis: Treatment has no impact, there is no difference, and there is no link.
2. Alternative Hypothesis: successful therapy, distinction, and link.
If the null hypothesis is proved to be false by experimentation, researchers will reject it. Until it is proven erroneous or untrue, researchers regard the null hypothesis as true and correct. The researchers, on the other hand, are attempting to bolster the alternative theory. A sample is subjected to the binomial test, which is followed by a series of tests (Frick, 1995).
STEP 1: Carefully evaluate and read the study topic before formulating a null hypothesis. Check the sample to see if the binomial proportion is supported. If there is no difference, determine the binomial parameter’s value.
The null hypothesis should be written as:
H0: p= if H0 is true, the value of p
Calculate the sample proportion to see how much it differs from the planned data and the null hypothesis value.
STEP 2: Locate the binomial test that falls under the null hypothesis in test statistics. The exam must be based on exact and comprehensive probability. Make a list of PMF that apply if the null hypothesis is proven to be true.
When H0 is true, X~b(n, p)
N = size of the sample
P = assume value if H0 proves true.
STEP 3: Determine the value of P, which is the likelihood of the data being seen.
When H0 is true, X~b(n, p)
N = size of the sample
P = assume value if H0 proves true.
STEP 4: Describe and describe the results or consequences in a descriptive manner.
An increase in the P value or a rise in the P value = Pr(X ≥ x)
X = observed number of successes
P value = Pr(X ≤ x).
Take note of the following:
1. Sample percentage
2. P-value
3. Differences in direction (either increases or decreases)
The statistical significance of the null hypothesis cannot be explained or expressed if the value of P is tiny, such as 0.10.
Perceived Problems With the Null Hypothesis
The main difficulties that impact the testing of the null hypothesis are variable or model selection and, in some circumstances, a lack of information. The null hypothesis’ statistical tests aren’t very powerful. When it comes to significance, there is some randomness. Gill (1999). The major problem with testing null hypotheses is that they’re all incorrect or untrue on the surface.
There is an additional issue with the a-level. This is an underappreciated but well-known issue. Because the value of a-level has no theoretical basis, typical values such as 0.q, 0.5, or 0.01 are subject to randomization. When a fixed value is utilised, two categories are formed (significant and non-significant). When there is a practical concern about the strength of the evidence connected to a scientific subject, the question of randomised rejection or non-rejection arises.
The P-value is crucial when testing the null hypothesis, but it has a flaw as an inferential tool and for interpretation. The chance of receiving a test statistic at least as severe as the observed one is the P-value.
The definition’s primary feature is that observed results are not reliant on a-value.
Furthermore, due to unseen outcomes, the evidence against the null hypothesis was exaggerated. More than merely a statement, the A-value has significance. It’s a detailed statement regarding the evidence based on the facts or outcomes that have been observed. P-values, too, have been determined to be undesirable by researchers.
They don’t like testing null hypotheses. It’s also obvious that the P-value is solely determined by the null hypothesis. It’s a type of computer-assisted statistics. The null hypothesis statistics and actual sample distribution are tightly connected in some exact experiments, but this is not achievable in observational research.
The P-value, according to some academics, is dependent on the sample size. A null hypothesis, even in a large sample, may be rejected if the real and exact difference is tiny. This illustrates the distinction between biological and statistical significance.
Another problem is the 0.1 fix a-level. A null hypothesis for a large sample may be accepted or rejected based on if a-level. There is still a possibility of Type I error if the size of the simple is infinite and the null hypothesis is proven true. As a result, this technique or procedure is not thought to be consistent or dependable.
Another issue is that precise information regarding the precision and magnitude of the predicted effect is unavailable. The only way to avoid this is to describe the effect’s magnitude and accuracy.
Null Hypothesis Examples
Null Hypothesis Example 1: Hypotheses in one categorical variable with one sample
Almost 10% of the human population prefers to perform tasks with their left hand, i.e., they are left-handed. Assume a researcher from the University of Pennsylvania claims that the majority of students at the College of Arts and Architecture are left-handed as compared to the overall population of individuals in general public society. There is just a sample in this situation, and the known population values are compared to the population percentage of sample value.
1. Research Question: In comparison to the general population, are artists more likely to be left-handed?
2. Response Variable: Classifying students into two groups. Left-handed people make up one group, while right-handed people make up the other.
3. Form Null Hypothesis: Arts and Architecture college students are no more likely to be left-handed than the general population (Lefty students in the Arts and Architecture college population account for 10% of the whole population, or p= 0.10).
Null Hypothesis Example 2: Hypotheses with one sample of one variable measurement
Diphenhydramine is a generic brand of antihistamine that comes in the form of a capsule with a 50mg dosage. The manufacturer of the medications is concerned that the machine has lost calibration and is no longer producing capsules with the proper dose.
1. Research Question: Does the suggested statistical data for the population’s mean and average dose differ from 50mg?
2. Response Variable: A chemical test that is used to determine the correct dose of an active substance.
3. Null Hypothesis: Typically, this trade name’s 50mg capsule dose (population average and mean dosage =50 mg).
Null Hypothesis Example 3: Two samples of one categorical variable in hypotheses
On a daily basis, a number of people choose vegetarian meals. Females, according to the researcher, prefer vegetarian meals to men.
1. Research Question: Does the evidence suggest that, on a regular basis, ladies (women) prefer vegetarian meals to males (men)?
2. Response Variable: Sorting people into vegetarian and non-vegetarian groups. Gender is a third factor that may be used to divide people into groups.
3. Null Hypothesis: is that there is no such thing as a null hypothesis. Those who enjoy vegetarian meals are not divided by gender. (% of women who eat vegetarian meals on a regular basis = % of males who eat vegetarian meals on a regular basis, or p women = p men.)
Null Hypothesis Example 4: Two samples of one measurement variable hypotheses
Obesity and being overweight is one of the most serious and severe health problems nowadays. A study is being conducted to see if a low-carbohydrate diet is more effective than a low-fat diet in terms of weight loss.
1. Research Question: Does the evidence suggest that a low-carbohydrate diet helps people lose weight more quickly than a low-fat diet?
2. Weight loss as a response variable (pounds)
3. Explanatory Variable: Low-carbohydrate or low-fat diet type
4. Null Hypothesis: When comparing the mean weight reduction of persons on a low carbohydrate diet to people on a low-fat diet, there is no significant difference. (Population means weight loss on a low-carbohydrate diet = population means weight loss on a low-fat diet).
Null Hypothesis Example 5: The relationship between two categorical variables hypotheses
A case-control experiment was carried out. Non-smokers, stroke patients, and controls are included in the research. The respondents were all of the same age and employment, and the query was whether or not someone in their immediate vicinity smoked.
1. Research Question: Does second-hand smoking make you more likely to have a stroke?
2. Variables: Variables are divided into two groups. (Patients with stroke and controls) (whether the smoker lives in the same house). If a person lives with a smoker, their chances of getting a stroke are enhanced.
3. Null Hypothesis: There is no link between being a passive smoker and having a stroke or a brain attack. (The odds ratio between stroke and passive smoking is 1).
Null Hypothesis Example 6: The relationship between two measurement variables hypotheses
1. Variables: The explanatory variable is stock acquired by non-management personnel the day before, and the response variable is daily price change data and information. These are two separate types of measurements. There are two main variables that may be measured.
A. Response Variable: Price fluctuation on a regular basis
B. Explanatory Variable: Non-management workers’ stock purchases
2. Null Hypothesis: The correlation and link between daily stock-buying by non-management workers ($) and regular stock price changes ($) = 0.
Null Hypothesis Example 7: Comparing the relationship between two measurement variables in two samples hypotheses
1. Research Question: Is there a linear relationship between a restaurant bill and the tip offered to the waiter? Is there a difference between dining and family restaurants in terms of this relationship?
2. Variables: There are two types of variables, each with its own set of characteristics. The tip amount is determined by the entire bill.
A. Explanatory Variable: the entire amount of the bill
B. Response Variable: the tip amount
3. Possible Null Hypothesis: In a family or dining restaurant, the link and association between the total bill quantity and the tip is the same.
Null Hypothesis Citations
- A review of issues about null hypothesis Bayesian testing. Psychol Methods . 2019 Dec;24(6):774-795.
- Macphail’s Null Hypothesis of Vertebrate Intelligence: Insights From Avian Cognition. Front Psychol . 2020 Jul 8;11:1692.
- Null hypothesis significance testing and effect sizes: can we ‘effect’ everything … or … anything? Curr Opin Pharmacol . 2020 Apr;51:68-77.
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Primary Succession: Definition, Types, and Examples
Continue ReadingPrimary Succession Definition
Ecological succession refers to the gradual evolution of a group of species or a community through time, such as decades or millions of years. Typically, one dominating group of living forms has succeeded in establishing a stable climax community across a certain region.
What is Primary Succession?
A Primary succession is an ecological succession in which a group of species or a community colonises a freshly created region for the first time. Topsoil and organic materials are generally sparse in this formerly deserted, desolate region.
The pioneer species is the species that colonises an unoccupied region for the first time, and the pioneer community is the dominant community. Soon, a broader diversity of plants and animals will populate the region, leading to the formation of a climax community.
The species occupying the region might be replaced by a new ecological succession, called secondary succession, if disturbed or interfered with by a disruptive external or internal cause.
Because the region had previously been occupied during the first succession, the second succession might happen much faster, in decades or even hundreds of years, as opposed to thousands or even millions of years during the initial succession.
Primary Succession Etymology
Adolphe Dureau de la Malle, a French scientist, was the first to use the term succession in an ecological context. The term refers to the growth of plants following forest clear-felling.
Type of Primary Succession
The process starts with a bare rock produced by volcanic eruptions or receding glaciers in this figure. The pioneer species (lichens and moss) that grow on the rock are the next stage. These species’ death and subsequent decomposition contribute to the creation of soil.
Grass and herbaceous plants are the next category of plant invaders. After that, shrubs and bushes take their place, followed by trees. Animals inhabiting the region are growing more varied as the diversity of plant species improves.
However, when competition for sunshine, space, and nutrients increases, those that are better suited and more tolerant, such as “shade-tolerant trees,” survive and grow.
i. Primary Succession
A succession of prevailing species communities in a certain environment characterises both kinds. They differ in terms of the habitat’s ecological history and genesis.
When a group of species or a community colonises a barren, freshly created environment, for example, this is known as primary succession.
The formation of plant or animal communities in a location where there is no soil at first, such as bare rocks created by a lava flow, is an example of primary succession. The colonization of a barren region following a catastrophic landslide or newly exposed land from retreating glaciers are two more instances.
Another is the colonisation of difficult environments like sand dunes. Sand dunes are only habitable by a few highly specialised flora and animals due to their extraordinarily scorching temperatures.
ii Secondary Succession
When a previously inhabited region is colonised by a new dominant group of species or communities, this is known as secondary succession.
In secondary succession, new occupants take the place of earlier groups in a habitat that has been affected by an ecological disturbance. The source of the disruption might be external or internal. The recolonization of a burned-out region is an example of secondary succession.
The habitat type is another distinction between main and secondary successions. Living creatures colonise a barren terrain, which implies it lacks topsoil, in primary succession.
In secondary succession, on the other hand, living creatures will re-colonize a previously occupied region, resulting in topsoil containing organic materials from the previous occupants.
Primary Succession Process
Primary succession takes a long time to develop and complete, perhaps a thousand years or more. On the other hand, secondary succession frequently happens more quickly, taking just a decade or a hundred years. This is due to the fact that most living forms would find a freshly created region undesirable at first.
The newly created area, for example, would be devoid of soil and made up entirely of bare rocks. Primary succession begins at this stage. A sequence of physicochemical modifications must take place till they become more hospitable to life.
Pioneer species are species that may effectively establish and control a newly created or previously unoccupied territory. Pioneer communities are communities that have successfully developed and dominated newly formed or previously uninhabited land.
A community is an ecological unit made up of a collection of organisms or a population of several species that live in a certain region. A community can be a tiny population living in a small area (such as a pond) or a huge geographical region that defines a biome.
The colonisation phase of primary succession begins with the establishment of a pioneer village. Lichens, algae, and fungus are examples of pioneer species.
These species are more tolerant, and by breaking down rocks into tiny pieces, they eventually contribute to the creation of soil. They also provide organic materials for the environment. The region eventually became loaded with thin soil, making it suitable for the establishment of higher kinds of species.
Intermediate species are the following species that invade and dominate the region. Grasses and shrubs that flourish on thin soils are examples. A greater diversity of plants and tiny animals can occupy the region as the environment improves.
The formation of a climax community, or a community made up of even higher forms of life, such as shade-tolerant plants and taller trees that attract larger and higher types of animals, is the last step.
Secondary Succession Process
The second succession happens when the habitat is subjected to a disturbance that threatens the habitat’s occupants. Because the region is already populated by plants and animals, it will likely stay livable after the disruption, making re-colonization quicker and more accessible.
In secondary succession, top soil is found whereas is absent in primary succession. Shorter period is seen in secondary succession and longer duration in primary succession.
Example are retreated glaciers for primary succession and tornado’s, flood, fire are secondary succession. A third kind, known as cyclic succession, occurs when a group of species gradually replaces a previously dominating species over time without causing large-scale disruption.
Importance of Primary Succession
The main succession is critical for pioneering the region and creating suitable conditions for the establishment of additional plants and animals. It prepares the stage for future successions, since formerly flourishing organisms may become an important part of the soil.
Because pioneer species are more tolerant of adverse environments, they might take the available nutrients and transform them into a form that other life forms could utilise.
Primary Succession Citations
- How lichens impact on terrestrial community and ecosystem properties. Biol Rev Camb Philos Soc . 2017 Aug;92(3):1720-1738.
- Changes through time: integrating microorganisms into the study of succession. Res Microbiol . 2010 Oct;161(8):635-42.
- Gopher mounds decrease nutrient cycling rates and increase adjacent vegetation in volcanic primary succession. Oecologia . 2014a Dec;176(4):1135-50.
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Pleiotropy: Definition, Mechanism, and Examples
Continue ReadingPleiotropy Definition
Pleiotropy is a phenomenon that occurs when a single gene affects several characteristics of living creatures. Pleiotropy can be caused by a gene mutation. Marfan syndrome, a human genetic disease affecting the connective tissues, is an example of pleiotropy.
The eyes, heart, blood vessels, and bones are all often affected by this illness. Pleiotropy is produced by a mutation in a human gene that causes Marfan Syndrome.
What is Pleiotropy?
Pleiotropy is derived from the Greek pleio, which means “many,” and trepein, which means “influence.” Pleiotropy is the state of having numerous effects.
It is a term used in genetics to describe a single gene that controls or influences several (potentially unrelated) phenotypic characteristics. In pharmacology, it’s a characteristic of a medication that causes it to have extra (positive) effects in addition to the ones it was designed to have.
It is demonstrated in molecular biology by cyclic AMP in a cell, which has a range of effects via controlling a protein kinase, which impacts a variety of other proteins.
Is Cystic Fibrosis an Example of Pleiotropy?
One of the most frequent examples of pleiotropy is cystic fibrosis, which is a hereditary disease. Lung infections are common with this condition. The digestive system and other organs in the body might be affected by this condition. Cystic fibrosis is caused by a mutation in the “cystic fibrosis transmembrane conductance regulator gene,” which prevents the gene from functioning properly.
Is Albinism a Pleiotropy?
Albinism is caused by a pleiotropic gene produced by a tyrosinase (TYR) gene mutation. The afflicted person’s body produces less melanin as a result of the mutation.
Pleiotropic genes are genes that influence the behaviour and functions of several genes with unrelated characteristics. On occasion, such qualities have been seen to be extremely similar in nature, while in other situations, they have been noted to be very unlike.
Pleiotropic characteristics are a term used to describe the issues caused by pleiotropic genes.
Effect of Genes on Traits of Humans
The phenotype refers to the physical characteristics of a person, such as body shape, height, colour, physique, and height. A trait governed or controlled by a single gene is known as a single gene trait. It may be difficult to determine the presence of pleiotropic characteristics until the gene is subjected to mutation.
Mutations are alterations in DNA sequences that occur relative to one another. The point mutation is the most frequent form of gene mutation, which is further divided into silent mutations, nonsense mutations, and missense mutations.
The character of the qualities is generally determined by the two alleles, which are the variation forms of a gene, according to diverse publications. The combinations of particular alleles dictate the synthesis of proteins that derive the process of phenotypic trait development, whilst the DNA sequence of the gene is altered by the mutation that occurs in the gene.
As a result, alterations in the gene segment sequences cause the proteins to stop working. As a result, the progression in the mutation will affect all accessible characteristics that are connected to a single attribute in the pleiotropy process.
Pleiotropy in Genetics
Pleiotropy was first proposed in biology by Gregor Mendel, a well-known geneticist well known for his groundbreaking work on pea plants. He tried purple-flowered plants and white-flowered plants in a series of trials.
Colorful blooms and leaf axils are always visible on plants with coloured seed coats, he observed. An axis is the portion of the plant that connects the stems to the rest of the plant.
He noticed that, although the seed coats were colourless in nature and had no colour in their axis, the pea plants, which were the focus of the study, invariably had white blooms.
After reviewing his findings, it was determined that the colour of the plant’s axil and the seat coat are the most crucial elements in determining whether the plant would produce white or purple flowers. Today, similar findings are attributed to the phenomenon of pleiotropy, in which a single gene contributes to numerous phenotypic characteristics.
Pleiotropy may be caused by a number of different processes, including development pleiotropy, gene pleiotropy, and selectional pleiotropy.
The focus of gene pleiotropy is on the functionality of a specific gene, and this type of pleiotropy is also known as molecular gene pleiotropy. The functions of a characteristic are generally determined by the number of traits and biochemical components influenced by the gene.
The biochemical parameters include the number of enzyme reactions performed by the gene’s protein products. In the evolution of pleiotropy, the major focus is on mutations and their relative influence on a variety of characteristics. It has been shown that single-gene alterations have a broader influence on numerous other potential characteristics.
Furthermore, illnesses involving mutational pleiotropy are defined by deficits in many organs that disrupt the proper functioning of multiple bodily systems. The last process that causes pleiotropy is selectional pleiotropy, which focuses on the impact of gene mutations on the number of distinct fitness components.
The method by which an organism transmits its genes from one generation to the next through sexual reproduction is typically governed by the fitness of the organism. Selectional pleiotropy is frequently concerned with the effects of selection on naturally occurring characteristics.
Polygenic vs Pleiotropy
Many people confuse the meanings of polygenic inheritance with pleiotropy, which is a common finding. The main difference between the two is that pleiotropy occurs when a single gene influences several traits, whereas polygenic inheritance occurs when a single trait is regulated by many distinct genes, such as skin colour.
Pleiotropy vs Epistasis
Understanding the idea and meaning of epistasis, as well as its relationship to pleiotropy, is also critical.
Epistasis refers to the interplay of several genes in influencing phenotypic results.
Pleiotropic gene research is important in biology because it helps researchers understand how specific genes are frequently implicated in genetic diseases. Pleiotropy may be found in abundance throughout nature.
Pleiotropic disorders include fruit flies with vestigial genes, poultry with frizzle characteristics, the process of pigmentation and deafness in cats, pleiotropic sickle cell diseases in humans, and phenylketonuria (commonly known as PKU).
Pleiotropy Examples
Pleiotropy is influenced by both direct and indirect pleiotropy, as evidenced by instances found in numerous literature research.
For example, if a blind mouse is born as a result of changes in a single gene, the odds are quite high that the blind born mouse will struggle with visual learning tests, showing that a single gene is implicated in many pathways.
As a result, there are numerous examples of both direct and indirect pleiotropy, some of which are discussed in further detail in the sections below.
i. The Vestigial Gene and Fruit Flies
Vestigial genes are important in the development of the wing of the fruit fly Drosophila. If these flies are homozygous for the recessive version of the vestigial gene, they have small wings and are unable to fly in the proper manner (VG). As a result, the vestigial gene is pleiotropic, resulting in the fruit fly drosophila’s wings not developing.
Other indirect impacts of pleiotropy in fruit flies include a reduction in the number of eggs present in the ovaries of the flies, a shift in the location of the bristles on the scutellum of the flies, and a shorter life span of the flies. The wings of the first bee are not entirely formed, as opposed to the fully developed wings of the second bee.
ii. Deafness and Pigmentation in Cats
Deafness is present in around 40% of cats with white hair and blue eyes, according to reports. Although this information is intriguing because we have most likely never paid attention to these cats throughout our lives.
It was discovered early on in the research that white cats with one blue eye and one yellow eye were blind in one eye, which was typically the blue eye, but it was subsequently shown that this occurrence of blindness does not necessarily apply to all cat breeds.
Waardenburg syndrome is a human disease that is comparable. Pleiotropic genes are involved in this disease in cats, producing not just deafness but also colouring issues. The goal of the study was to figure out how hearing capacity and the pigmentation process are linked.
Pigmentation has a critical function in regulating fluid flow in the ear canals, according to the findings, which were conducted on mice. Those who lacked pigmentation also lacked the flow of fluids through the ear canals, causing them to rupture and eventually lead to deafness.
iii. Frizzle Traits of Chickens
Pleiotropic genes cause the hens to express a variety of genes. Walter Landauer and Elizabeth Upham discovered in 1963 that hens with the dominant frizzle gene generate feathers that curl all over their bodies rather than laying flat against their skin.
This impact was linked to the genes’ phenotypic effects. Furthermore, it was discovered that these frizzle characteristics induced a variety of alterations in the hens, including aberrant body temperatures, high blood flow rates, high metabolic rates, and increased digestive capacity.
Furthermore, as compared to typical wild eggs, the hens with pleiotropic characteristics produced fewer eggs, affecting their reproduction rates.
iv. Marfan Syndrome
The Marfan syndrome is a hereditary disease that causes problems with tissue connections. The eyes, heart, bones, and blood arteries are the most commonly affected parts of this condition. People who suffer from these disorders generally have long, slender bodies with long legs, arms, fingers, and toes, and the Marfan syndrome can cause mild to severe damage.
The symptoms of the condition differ from one family to the next, and they also differ by age, with some experiencing minor symptoms and others experiencing life-threatening problems. Cardiovascular problems include aortic aneurysms, aortic dissections, and valve abnormalities.
Eye difficulties, such as lens dislocations, retinal issues, and early-onset glaucoma, commonly known as cataracts, are, on the other hand, extremely essential.
v. Sickle Cell Disease
The most frequent kind of pleiotropy that affects humans is sickle cell disease, which is caused by a condition that causes irregularly shaped red blood cells, whereas normal red blood cells have a biconcave, disc-like shape and contain large amounts of haemoglobin.
Red blood cells in the blood are primarily responsible for binding tissues and transporting oxygen to all accessible cells. Sickle cells are most commonly caused by mutations in the beta-globin gene. As a result, irregularly shaped blood cells cluster together, creating a block in the veins and eventually stopping blood flow in the veins.
This obstruction causes a slew of health issues as well as harm to critical human organs, including the heart, brain, and lungs.
vi. Phenylketonuria
Phenylketonuria, or PKU, is another frequent type of pleiotropy, which causes mental impairment, hair loss, and changes in skin colour or pigmentation. The majority of these illnesses are caused by a significant number of mutations in a single gene on a chromosome.
These genes are involved in the synthesis of phenylalanine hydroxylase enzymes. These enzymes are responsible for breaking down the amino acid phenylalanine, which we obtain via protein digestion. Pleiotropy causes the nervous system to be harmed when the amount of amino acids rises owing to pleiotropy.
Other diseases induced by phenylketonuria include intellectual impairments, cardiac issues, developmental delays, and seizures. Classic PKU is the most prevalent kind of PKU, and it usually affects infants. The prevalence of these disorders varies depending on where you live.
In the United States, one out of every ten thousand newborns is affected by this illness. The good news is that doctors can diagnose PKU in newborns based on their early symptoms, allowing them to begin therapy early and save the youngsters from the disease’s devastating consequences.
Antagonistic Pleiotropy
Antagonistic pleiotropy is a theory offered to explain senescence or biological ageing that can be ascribed to natural selection of specific pleiotropic genes.
Natural selection may prefer an allele that has a detrimental influence on the organism if it also provides beneficial aspects of antagonistic pleiotropy. Furthermore, natural selection favours genotypes that improve reproductive fitness early in life but induce biological ageing later in life.
The sickle cell, where the Hb-S allele mutation of the haemoglobin gene gives varied advantages and drawbacks for their survival, is the most typical example of antagonistic pleiotropy.
The homozygous for the Hb-S allele, which has a couple of Hb-S alleles of the haemoglobin allele, has a shorter lifespan due to the negative effects of sickle cell traits, whereas the heterozygous traits, which usually have one normal allele and a single Hb-S allele, are highly resistant to malaria and do not have the same negative symptoms.
Furthermore, it may be deduced that the frequency of the Hb-S allele is higher in geographical areas with higher malaria transmission rates. Lethal alleles are those that result in the death of the individual who has them.
Generally, they are the result of gene mutations that are highly important for an individual’s development and growth. A dominant, recessive, or codominant allele can exist. An individual with the AB blood type possesses both alleles, i.e. allele A and allele B. This is an example of a codominant allele.
Pleiotropy Summary
Pleiotropy is a characteristic that demonstrates that several genes have many phenotypic effects, which may be summarised from the preceding explanation. Pleiotropy may be caused by a number of different processes, including development pleiotropy, gene pleiotropy, and selectional pleiotropy.
The focus of gene pleiotropy is on the gene’s functionality, whereas the focus of development and selectional pleiotropy is on mutations and their relative influence on numerous characteristics, and the effect of gene mutations on the number of distinct fitness components, respectively.
Pleiotropic gene research is important in biology because it helps researchers understand how particular genes are involved in a variety of genetic disorders. Pleiotropy is implicated in a number of genetic diseases that have been reported in the literature.
Deafness and pigmentation in cats, the prevalence of frizzle features in cats, Marfan syndrome in humans, sickle cell disease, phenylketonuria (PKU), albinism, Austin, and schizophrenia are only a few examples of pleiotropic qualities.
Pleiotropy Citations
- Evaluating the potential role of pleiotropy in Mendelian randomization studies. Hum Mol Genet . 2018 Aug 1;27(R2):R195-R208.
- Pleiotropy and Specificity: Insights from the Interleukin 6 Family of Cytokines. Immunity . 2019 Apr 16;50(4):812-831.
- What Is Antagonistic Pleiotropy? Biochemistry (Mosc) . 2019 Dec;84(12):1458-1468.
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Arboreal: Definition, Types, and Examples
Continue ReadingArboreal Definition
The word arboreal originates from a Latin word, which means like trees. Thus, it is associated with the trees and the words related to it are arborary, arborous and others.
Arboreal locomotion occurs when the organism residing in the trees show movement such as jumping, swinging and walking and is thus termed arboreal locomotion. As they reside on trees, their body has been adapted in that way, such as their tail, claws or their legs.
Arboreal Animals
Animals which reside on trees are called as arboreal animals, their whole life they lodge on the trees where all their daily activities are carried out such as hunting, mating, sleeping as well as leisure. Their offspring also reside on the trees however as they are very small, these juvenile are most susceptible to tumble down.
Parrots, cat, squirrel, lizards, insects, monkeys, chameleon, koalas, and sloths are the example of arboreal animals, however there are other animals who stay on land but can climb trees such as goats and leopards, where leopards get on the tree so that their prey cannot be taken by other animals.
These arboreal animals form the forest ecosystem and will be seen in such ecosystem, and more specifically in the tropical forests. Arboreal animals reside on trees to protect themselves and their family from scavengers on the land, however there are chances of them tumbling down.
Thus they have acquired certain adaptations such as they make their nests or their habitat at the peak of the trees and those animals which are huge in size will reside in the middle portion of the tress and will hide in the branches and leaves when they feel they could be hunted.
Challenges for Arboreal Animals and Adaptations
There are various problems which could be faced by the arboreal animals such as falling down which results in mishap. Other challenges are looking for food and storing them as well and protection and various daily activities they carry out.
Other problems could be inappropriate weather conditions resulting in loss of habitat as the branches fall of and balancing, walking on tiny branches and other obstacles are some of the issue. Although these problems are overcome as they have stayed on trees for a long duration, thus adapting to it.
i. Gravitational Balance
Center of gravity is responsible for the movement in animals, thus resulting in no friction. When cow walks it does not use both the legs at the same time it uses alternate legs, thus, the center of gravity is from side to side. Other examples of animals with excellent center of gravity are dogs, giraffe, buffalo and elephants.
However, the opposite is that of arboreal animals, i.e., they have low center of gravity which is due to small length of legs. Thus, they can maintain their balance and avoid tumbling down from tress due to center of gravity being low.
ii. Membranes for Gliding
Trees might have spaces between, thus arboreal animals have made gliding adaptations which is due to patagia, which is a membrane allowing sliding found between the legs. As it is flexible, they can jump from one branch to the other and will not fall down but glide in such scenario. These membrane contract and expand but does not possess weight on them.
In animals such as flying frogs, snakes, squirrels, mice and geckos possess this membrane as well, where they glide but not fly. Smallest gliding animal is the flying mouse and they possess the membrane between their knees and their elbows. While gliding it requires its tail and is a rodent.
iii. Body Structure
As arboreal animals spend their whole life on their tree, they have acquired some adaptation such as the gliding membrane, swinging and brachiation. Brachiation is the ability of the arboreal animals to shift from one branch to the other which is seen in monkeys, apes, lemur and other primates.
Other adaptations are long arms which helps them to swing and move from branches to branches and the gaps present between the trees. 35miles/hour is the monkey’s speed. The wrist of arboreal animal can move freely which helps to catch hold off the branches while moving and swinging.
Arboreal animals have prehensile tail and the most classic example are the monkeys, where tail provides support, helps in jumping, swinging, moving, snatching. To prevent from tumbling down and getting bruised, these animals have grip in their feet so that they can hold the branches very firmly and their fingers lack hair thus providing a grip when they hold branches.
Example are squirrel which have easily rotatable ankles, thus can move both the sides very quickly. Other adaptations are shorter feet, thumb, spine, nails and long fingers and forelimb. Some arboreal animal have adhesive feet and its example are tree frogs and salamander.
Arboreal animals are usually small which has various pros like low center of gravity, less weight and more stability. The exception are orangutans which are around 300 pounds in weight and reside in tropical forest.
Arboreal Locomotion
Arboreal locomotion occurs when the organism residing in the trees show movement such as jumping, swinging and walking and is thus termed arboreal locomotion. As they reside on trees, their body has been adapted in that way, such as their tail, claws or their legs.
The adaptations are long arms which helps them to swing and move from branches to branches and the gaps present between the trees. Many times, when they fight and play, they don’t tumble because of the adaptations made by the body and their locomotion which prevents from falling when they have skipped a branch and are about to fall.
The type of locomotion varies from animals to animals such as concertina locomotion is seen in snakes.
Arboreal Examples
The examples of Arboreal animals residing in the tropical, subtropical area are:
a) Orangutan: They are found at the peak of trees and don’t come down very often. Their feet and hands are not considered separate as they both can perform the same functions like swinging, climbing, snatching and etc.
b) Tree Kangaroo: They reside in the New Guinea tropical rainforest and are actual arboreal staying on trees. Tree kangaroo also reside on the peak and have human speed when on the land. The features of kangaroo are strong forelimbs and legs. Their jump is quite excellent as they possess the ability to jump 30 feet down from one tree to the other.
c) Sunda Flying Lemur: Lemur are agile during night, thus sleep in day at the top or in the holes of the tree and requires all its four leg to obtain a hold on the tree’s branches. To climb they using hoping where they spread their legs and jump.
Sunda colugo and Malayan colugo are the other names of the lemur. It does not stay on the ground and has gliding membrane which is present from the neck to the toes, thus making gliding very smooth.
Arboreal Citations
- Positional behavior and body size of arboreal primates: a theoretical framework for field studies and an illustration of its application. Am J Phys Anthropol . 1992 Jul;88(3):273-83.
- Hindlimb suspension and hind foot reversal in Varecia variegata and other arboreal mammals. Am J Phys Anthropol . 1997 May;103(1):85-102.
- Fomitopsis officinalis: a Species of Arboreal Mushroom with Promising Biological and Medicinal Properties. Chem Biodivers . 2020 Jun;17(6):e2000213.
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Plasmolysis: Definition, Mechanism, and Examples
Continue ReadingPlasmolysis Definition
Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, deplasmolysis or cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell.
What is Plasmolysis?
Plasmolysis can be divided into two words, where plasma means matrix and lysis means loosening. The desiccation of the cell’s protoplast due to loss of water, which occurs at a distance from the plant, is called as Plasmolysis.
Thus, voids are seen between the plasma membrane and the cell wall. Convex and concave are the two plasmolysis types.
Shrinking of protoplasm whereas, concave pockets are formed by plasma membrane in concave plasmolysis, however there exist common places between the protoplasm and cell wall. With hypotonic solution, the situation can be reversed for concave plasmolysis.
From the cell wall, protoplast has separated itself and the cell is now of spherical shape and this convex protoplast, which cannot be reversed.
Crenation is seen in animals, which is nothing but plasmolysis, and the cells are contracted, however plants does not contract because of the cell wall, thus possess concave pockets or are circular.
Plasmolysis vs Cytolysis
Plasmolysis and cytolysis are separate as the cell ruptures due to the amount of water present in the cell, more than the cell can hold and this happens when the cell comes in contact with a hypotonic solution and the water keeps on entering the cell more than the limit of the cell, resulting in cytolysis. This is seen in red blood cell, which explodes but does not happen in plants as they turgor pressure and cell wall.
Due to variation in osmotic pressure and movement plasmolysis and cytolysis occurs. In plasmolysis water exits from the cell due to hypertonic environment, whereas in cytolysis water moves inside due to hypotonic conditions. Thus, they are the opposite of each other.
Plasmolysis vs Turgidity
Due to variation in osmotic concentration of solutes in the solution and movement plasmolysis and turgidity occurs. In plasmolysis, the water is thrown out of the cell, whereas in turgidity, there is influx of water. Thus, contraction of cell takes place due to plasma membrane and protoplasm gets isolated from cell wall and the opposite of this occurs in turgidity.
Turgidity takes place when cell is placed in hypotonic solution and plasmolysis occurs when there is hypertonic condition. Thus, turgor pressure elevates in turgidity and drops in plasmolysis. Thus, the plants in turgidity stands straight and bend down in plasmolysis.
Plasmolysis vs Flaccidity
In plasmolysis, the water is thrown out of the cell, due to hypertonic environment. Thus, contraction of cell takes place where, plasma membrane and protoplasm gets isolated from cell wall. Due to absence of water between the plant and the surrounding, turgor is lost, thus flaccidity occurs. Such a cell is neither contracted nor expanded.
However, these processes quite resemble each other as water is lost and they start to bend down which is the plant. Both these conditions can be normalized once the cell is near the hypotonic environment.
Plasmolysis Process
Appropriate solute concentration and pressure in the plant is maintained by the vacuole, whose work is osmoregulation. Water diffuses into the cell when there is variation in solute or water concentration. The movement of water from a region of high water to a region of low water is called as Osmosis. Water will always move to a region which has a greater number of solutes, when referring to solute.
Turgor pressure can be kept under control if salt and water amount is maintained. To maintain the structure of plants, water molecules possess pressure which will move them towards the plant cell, thus maintain structure.
Thus, plant turgidity is very vital, as it limits the water amount and takes up only the required amount of water and if this turgor pressure is imbalanced or damaged then the plant will not be able to stand through in isotonic environment, which means when the concentration of solute within the environment and the cell is similar.
Such a cell is called plasmolyzed and is no more turgid and can be called as a flaccid cell. Hypertonic is those that has more salt than water, and in such a hypertonic condition, cell will release water and this process is plasmolysis and the cell is in plasmolyzed condition.
However, this process can be over turned by de-plasmolysis and if the water is effluxed continuously it would lead to cytorrhysis, where the wall of the cell is disintegrated. Plasmolysis is performed in lab when cells ae exposed to sugar or salt in high concentration. However, this process does not happen in the environment.
Concave vs Cconvex Plasmolysis
The desiccation of the cell’s protoplast due to loss of water, which occurs at a distance from the plant, is called as Plasmolysis. Thus, voids are seen between the plasma membrane and the cell wall. Convex and concave are the two plasmolysis types.
Shrinking of protoplasm whereas, concave pockets are formed by plasma membrane in concave plasmolysis, however there exist common places between the protoplasm and cell wall. With hypotonic solution, the situation can be reversed for concave plasmolysis, by de-plasmolysis.
From the cell wall, protoplast has separated itself and the cell is now of spherical shape and this convex protoplast, which cannot be reversed. Plants produce wax and control stomata so that water is not released.
Plasmolysis Examples
Plasmolysis is performed in lab where cells are exposed to sugar or salt in high concentration. However, this process does not happen in the environment. However, some examples are flooding of coastal areas with elevated salt content and when they are left unprotected to chemicals such as weedicides.
Plasmolysis Importance
In plasmolysis, the water is thrown out of the cell, due to hypertonic environment. Thus, contraction of cell takes place where, plasma membrane and protoplasm gets isolated from cell wall. Voids are seen between the plasma membrane and the cell wall.
From the cell wall, protoplast has separated itself and will signal the plant to start absorbing water and stop further loss of water, which is the backup plan of plasmolysis until cytorrhysis has arrived, which will eventually disintegrate the cell wall and finally apoptosis.
Plasmolysis Citations
- The biophysics of the gram-negative periplasmic space. Crit Rev Microbiol . 1998;24(1):23-59.
- Salt stress or salt shock: which genes are we studying? J Exp Bot . 2013 Jan;64(1):119-27.
- Significance of plasmolysis spaces as markers for periseptal annuli and adhesion sites. Mol Microbiol . 1994 Nov;14(4):597-607.
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Diploid: Definition, Structure, and Examples
Continue ReadingDiploid Definition
The word diploid originates from a Greek word, which can be broken into two word “di” meaning two and “ploidy” means the chromosome set present within the cell. thus, diploid means there are two set of similar chromosome, each coming from the parent cell.
The chromosome are similar as they possess traits which are obtained from the parent and similar case is seen in humans, where they obtain genes from parents. As diploid means two set of chromosomes, haploid comprises of one set of chromosome.
Example of haploid cell are sex cells which come together and form a zygote which is diploid. Example of diploid cell are somatic cell. thus, humans have 2 cell types and they are; somatic and sex cell. the chromosome number is “2n” in diploid and “n” in haploid.
Ploidy
Depending on the number of set of chromosome present, they can be categorized. This is called as ploidy. Those are termed as polyploidy which contain either three set or more than that.
In silkworms, there are 10,48,576 ploidy, whereas in human it is deadly and can result in complication in the pregnancy and has to be terminated. Visibility of an extra chromosome can result in a condition which is aneuploidy observed in humans, resulting in disorder such as trisomy 21 or Down syndrome, trisomy 18 or Edwards syndrome and trisomy 13 which is Patau syndrome.
In monosomy, chromosomes are absent, example is Turner syndrome, where female lack chromosome or is dysfunctional. Polyploidy occurs in plants and not in higher animals. Example are African frog, potato, rat in which polyploidy is observed.
In heptaploid, seven chromosome sets are observed. In hexaploidy six sets of chromosomes, five set of chromosomes in pentaploidy, four sets in tetraploidy, three sets in triploidy, in diploid two sets of chromosome and in haploid one set of chromosome.
Humans have a pair of 23 chromosomes, thus 2n = 46. These 23 can be further divided into 22 somatic cell and one sex cell. all the cells in the human body are diploid except the sex cell which consist of egg and sperm and are haploid, with 23 chromosomes. However, these sex cells when fuses they form a zygote which is diploid. Thus, the chromosome number remains stable.
For the formation of sex which are haploid, meiosis occurs and when these sex will tur to diploid after which they will undergo mitosis. Meiosis takes place to form four daughter cell, with each daughter having half chromosome from the parent cell. formation of two daughter cell, where each one contain similar chromosome number. Example are the bees, ants which are developed from meiosis and are known as haploid organism.
Haploid cell possess one chromosome set, whereas the diploid has two sets. Diploid cells further undergo mitosis and haploid cells are formed by meiosis. Example of diploid are somatic cell and that of haploid are sex cells. The daughter cells formed in meiosis are not similar to the parent, whereas in mitosis daughter cells are identical. Eggs and sperm are haploid and skin cells are diploid.
Diploid Examples
There are 23 pair of chromosomes in human which means 46 chromosome in total. Earthworm possess 18 chromosome pair and dogs have 39 chromosome pair, thus 78 chromosomes. There is just a single chromosome in E. coli, animals cannot change from haploid through diploid but plants ae capable to do so and is called as alternation of generation. Example is during gamete formation, plants are haploid and during spore production, diploid. Viruses are also diploid as they possess two RNA.
Biological Importance of Diploid
It is said that there are high mutations probability in diploid than in haploid which is because of more chromosome, thus doubling it in diploids. Although these mutations will affect those diploid cells which are surviving through difficulty, but diploids have better thriving rate than the haploid, thus if a haploid cell gets mutated it comes into action at that possible time and in diploid, they are effective when they are heterozygous.
Mutations can be hold on to in haploids than in diploids, thus diploids are quite adapted when changes are occurring due to mutation, however, haploids are better adapted when changes are due to natural selection.
Diploid Citations
- Diploid sperm and the origin of triploidy. Hum Reprod . 2002 Jan;17(1):5-7.
- Physiological polyspermy: Selection of a sperm nucleus for the development of diploid genomes in amphibians. Mol Reprod Dev . 2020 Mar;87(3):358-369.
- Unzipping haplotypes in diploid and polyploid genomes. Comput Struct Biotechnol J . 2019 Dec 9;18:66-72.
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Humans are Omnivores? Diet and Evidence
Continue ReadingHumans are Omnivores
There are various misbelieves about the diet of a human, some say they are herbivores, consume plant-based diet and some say they are complete carnivores, eating animal’s flesh. Thus, to prove this various scientist have undergone research and have found that humans are actually omnivores, feeding on both. This fact was proved by Dr. McArdle, a primatologist and anatomist.
Taxonomy and Diet
The myth that humans are complete vegetarians have been arisen due to lack of certainty about the diet and the taxonomy. Carnivores can be specific to a particular diet or can eat various flesh, thus belonging to carnivores.
The diet cannot be just classified into herbivores or carnivores but insectivores are those which eat insects, frugivores which consume fruits, gramnivores eat seed and nuts, whereas folivores consume leaves.
He concluded by saying that every organism has a particular function and those functions are also found in other species.
Omnivores
Omnivores are said to be those organism, that are both herbivores as well as carnivores, which is a type of adaptation accomplished by them. Thus, to thrive in the environment they have acquired this type of adaptation and feed on whatever is available.
This adaptation is seen only in animals and humans have the freedom to choose what they want to consume. However, in animals a few characteristic have been seen such as modified teeth which can also be an adaptation.
Great Apes and Their Diet
Species differ from each other in their food characteristic, is said by Dr. McArdle. Animals that consume fruits are the apes, however there are other types of apes which also eat fruit but differ in the habits and the habitat, example gibbons and siamangs.
There are other animals that are on plant-based diet but does not eat much fruit are the gorilla and orangutans which have not been viewed eating non-vegetarian food. A comparison was done to identify the link between the primate’s diet and their size. It was found out that the tiniest species fees on insect, called the insectivores and the one which is the hugest is an herbivore.
Thus, it determines the amount of food consumed according to the size and the food available on the basis of the location. Organism that quite resemble the humans in their habits, physiology, characteristic and the genetics are the chimpanzee, which hunt the prey to feed themselves.
Evidence that Humans are Omnivores
a) Archeological Records: From the records it has been very evident that since the ancient times humans have been killing other animals to obtain food and they are potential carnivores. Thus, humans are omnivores.
b) Anatomical Features: There are features that humans have similar to omnivores on the basis of their body. Example are mice, pigs, rodents and others. Although omnivores do not have vats where food is broken down by microflora, but is present in deer and cattle and there are sacs found in animals such as monkey, rhinos and horses, and sharp teeth, but humans do not possess such features. However, humans have other features.
c) Jaws and Teeth: One of the most important feature of omnivores that are humans are the teeth which have canines which are quite small due to cranium enlargement and small size of the jaw. However, in animals the canines are huge as they help to prove their dominance as well as to eat their food. In humans the canine and premolar and molar are enough to break the food.
d) Intestines: The most tedious digestive system is of herbivores due to the presence of various compartments, then the carnivores and omnivores. As the plant-based diet is quite rigid, thus breaking it is more complex in nature. Thus, they possess more organs for digestion to occur. The easier to broken one are the carnivores, whereas the omnivores are in between the herbivore and carnivore, not complex as well as not easy. Those plant substances that cannot be broken by humans are thrown out of the body.
Thus, humans are omnivores and have the freedom to choose the type of diet, however in animal it is an adaptation made by them for survival.
Humans are Omnivores Citations
- Vegetarian diets : nutritional considerations for athletes. Sports Med . 2006;36(4):293-305.
- Nutritional considerations for vegetarian athletes. Nutrition . Jul-Aug 2004;20(7-8):696-703.
- Vegetarian and Omnivorous Nutrition – Comparing Physical Performance. Int J Sport Nutr Exerc Metab . 2016 Jun;26(3):212-20.
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Polysaccharide: Definition, Structure, and Examples
Continue ReadingWhat is Polysaccharide?
Polysaccharide are chains of carbohydrate that are connected to each other by glycosidic bond and consist of repeating carbohydrate to form a long chain. The term polysaccharide can be broken into words, where poly means many and saccharide means various sugars.
Thus, it means a group of various sugars consisting around 10 moieties. These carbohydrate moieties, are the biomolecules which are made up carbon, hydrogen and oxygen. Carbohydrates can be categorized in two; simple and complex.
Carbohydrates forms the structure and are the energy source. Carbohydrates that can be easily broken down, to provide energy are termed as simple carbohydrate, whereas those that require time to be broken down, however does not interfere with the increment of sugar level and are fibrous in nature are called as complex carbohydrates.
Example of simple carbohydrate are glucose and that of complex carbohydrate are chitin, glycogen and cellulose.
Polysaccharide Characteristics
a) The formula for polysaccharide are Cx (H2O) y.
b) The ration of carbon to hydrogen to oxygen is 1:2:1.
c) Polysaccharide do not dissolute in water.
d) They are less active and are present in condensed form.
e) In taste they aren’t pleasing.
f) They cannot form crystals
g) They are white in color on isolation.
The polysaccharide can be heterogenous and its structure will be branched or linear depending on the polysaccharide it forms. On the basis of sugar molecules, oligosaccharide and disaccharide differ from polysaccharide, where 2 sugar molecules are the disaccharide and more than that sugar moieties are called as oligosaccharide, however they aren’t huge like the polysaccharides.
Polysaccharide Dehydration Synthesis
Dehydration means water is been worn out of a molecule, in polysaccharide it happens when to a sugar molecule another molecule gets attached and results in the expulsion of water molecule. Another way for synthesis to occur is when the sugar molecule attach to the other molecule, they are in a condensed form and water is expelled.
Polysaccharide Hydrolysis
Hydrolysis is the exact reversion of condensation, where a water molecule is lost. In hydrolysis water molecule gets used. To form a monosaccharide from polysaccharide it is known as saccharification. Enzymes such as maltase, pancreatic and salivary amylase break down the sugar molecule, such as the enzyme acting on starch is salivary amylase, resulting in the formation of maltose.
In the small intestine, further the digestion of carbohydrate will take place. In the small intestine, when the partly digested sugar molecule reach, pancreatic juice is released by the pancreas, which will further degrade them into small sugars.
There are enzymes present on the borders of intestine, which will take up the simple sugars with the use of transporters and through the passive transport will reach the capillaries and will be moved to organs such as liver, where it will serve as reserves for glycogen or it could also synthesize ATP.
The enzymes are found on the border of intestine are sucrase, lactase, maltase and isomaltase. These polysaccharide will be attacked at the 1-6 linkage and will form maltose, which will further be cleaved by the enzyme maltase forming glucose, explicitly two molecules.
If instead sucrose or lactose would be present then the respective enzyme sucrase and lactase would act on it. Only those sugar molecules which reach the large intestine, which cannot be absorbed and will be colonized by the microflora in the intestine anaerobically and release gases and fatty acid which are utilized by the body and the gases are released when we fart.
Glycogenesis
From glucose the formation of glycogen is known as the glycogenesis, which would occur when there is huge amount of glucose in the liver and the muscles. Large glucose chains are formed from small glucose molecule, and in the glycogenesis process from those sugar molecules which are present in the cell, glycogen is formed. These molecules when have to be utilized are again broken into glucose by the glycogenesis process.
Glycogenolysis
The metabolization of glycogen is known as glycogenolysis. From the glycogenolysis process, glucose is formed, where from the glycogen a glucose molecule is cleaved and forms glucose-1-phosphate and then again forms glucose-6-phosphate to proceed with the glycolysis. Glycogenolysis takes place in the liver.
Glycosylation
The attachment or linkage of a protein, organic molecule or a biomolecule to the glycan is known as glycosylation. For example, in O linked glycosylation, the O glycan is linked to the oxygen of amino acid such as tyrosine, threonine and etc.
Another example is N linked glycosylation where the N glycan is linked to nitrogen atom of another amino acid which is asparagine. There are various example such as Sulphur linked glycan, Phosphorous linked glycan, Carbon linked glycan and others.
Polysaccharide Classification
When the polysaccharide is formed from a single type of sugar it is called as Homopolysaccharide. Heteropolysaccharide is made up of various sugar molecules. These are two types of polysaccharide classification on the basis of the type of sugar present.
There are two types of polysaccharide and they are Storage polysaccharide and Structural polysaccharide. On the basis of their name is their function.
Structural polysaccharide are like chitin, cellulose which forms the structure of a certain animal. Example is to make the exoskeleton of animals, chitin is required.
Storage polysaccharide are those stress various sugar molecules serving as the reserves. For example, the storage of glycogen in animals in its simple form.
Polysaccharide Example
There are various polysaccharide such as cellulose which is made up of glucose molecules chains in a linear array. Another polysaccharide is glycogen which is formed in liver and muscle and comprises of glucose in a branched chain and is a storage polysaccharide in animals.
Another polysaccharide is Starch which connects glucose moiety to each other by glycosidic bond. A polysaccharide with nitrogen is the chitin, which is a structural polysaccharide that forms structure in various organism. Other example are Zylan, fucoidan, arabinoxylan, galactomannan and others.
Biological Importance of Polysaccharide
The major energy source is the carbohydrates, which are taken up by animals to produce ATP. Example using the substrate level phosphorylation, from glucose ATP is produced. However excess amount of glucose can result in diabetes and similarly excess of fructose can could result improper absorption from small intestine.
Thus, to prevent that fructose is relocated to large intestine where it will be colonized by the micro-flora. In plants, they function as storage polysaccharide, such as storage of glucose in the starch form, which will used by plants to prepare food.
Glycogen is stored in animals, where it can be broken into glucose to meet the energy requirements. In animals, they also form the skeleton and covering of various organism and have industrial applications as well.
Polysaccharide Citations
- Biological activities and pharmaceutical applications of polysaccharide from natural resources: A review. Carbohydr Polym . 2018 Mar 1;183:91-101.
- Polysaccharide of Ganoderma and Its Bioactivities. Adv Exp Med Biol . 2019;1181:107-134.
- Natural Polysaccharide Nanomaterials: An Overview of Their Immunological Properties. Int J Mol Sci . 2019 Oct 14;20(20):5092.
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Smooth Endoplasmic Reticulum: Structure and Function
Continue ReadingWhat is Smooth Endoplasmic Reticulum?
In eukaryotes, smooth endoplasmic reticulum is found. smooth endoplasmic reticulum is a type of endoplasmic reticulum, in which ribosomes are absent and in structure is tubular.
Regulation of calcium level, removal of toxins from drug, metabolism of sugars are the function of smooth endoplasmic reticulum. It is a vital organ with various functions and comprises of a chain of tubules which are the cisternae.
Within the cell membrane and the nuclear envelope, the endoplasmic reticulum extends. There are two types of ER; smooth and rough ER. rER is located in protein generating cells.
Smooth endoplasmic reticulum is found in fatty acid cells and steroid hormones. Example of rER are plasma cells, liver cells, pancreatic cells and goblet cells.
Smooth endoplasmic reticulum is found in leucocytes, interstitial cells, heart’s conducting fibers, adipose cells and others.
Smooth Endoplasmic Reticulum Discovery
In 1902, smooth endoplasmic reticulum was first time seen in light microscope by a group of scientist and one of them was Charles Garnier, before that an important organelle like ER was not even discovered. Although it had to be proved whether ER actually subsisted, took around 50 years of wait, after the arrival of electron microscopy.
Inside the cytoplasm it appeared like netted structure and was thus called ER and its function, structure, working was all identified by 1960. It played a role in the protein synthesis was realized by Gunter Blobel around 1971.
Smooth Endoplasmic Reticulum Structure
As it does not possess ribosomes its surface is smooth, hence the name smooth endoplasmic reticulum. It is present in the cytoplasm and is linked to the nuclear envelope. Inside the reticulum is the net like structure in which tubules are present along with vesicles in the cytoplasm. As there are folding present in the ER, which increases the surface area so that the enzymes can act.
Lumen is present inside the smooth endoplasmic reticulum, which is encapsulated by a membrane of phospholipid. The tubules branches with the other tubules resulting in the formation of a 3D reticulum, however they may also exist in spiral shape in cells generating hormones.
Types of Smooth Endoplasmic Reticulum
Sarcoplasmic Reticulum: A type of smooth endoplasmic reticulum is the sarcoplasmic reticulum which is found in cells of muscle, whose function is to regulate the homeostasis of calcium. In structure they are tubular in shape surrounding the muscle and gather around the myofibril, in which is the cuff like structure of SR.
The functions are it controls the calcium concentrations, while the muscles are contracting. In structure there exist a net like structure in which are tubules spreading throughout the muscle, surrounds the myofibrils. Longitudinal and junctional sarcoplasmic reticulum are its domains.
The similarity in both the domains is that there is an arrangement of myofibrils which orient themselves with the sarcomeres. Tubules are in linear fashion and are connected to each other, surrounding the myofibril is called as longitudinal SR and the area where these tubules end are sac like structures called the terminal cisterna.
Smooth endoplasmic reticulum is the point of entry to the SR and the exit points are the ryanodine receptors along with cisterna. During the contraction of muscle, calcium is taken out from the SR and moves to the ryanodine reception, thus allowing the contraction to take place.
Then again, the calcium is reached to SR with the help of smooth endoplasmic reticulum during relaxation. Thus, acting like a pump and transporting calcium from cytoplasm to the SR and vice-versa.
Smooth Endoplasmic Reticulum Location
All types of eukaryotic cell possess smooth endoplasmic reticulum except mature RBC, embryo cells and ova. Hepatocytes, striated muscle cell, gonadal and sebaceous cell contain huge amount of smooth endoplasmic reticulum.
Smooth Endoplasmic Reticulum Function
Production of lipid, intracellular calcium regulation, drug detoxification, metabolism of sugar are some of the functions. Sebaceous cell, gonadal cell, hepatocytes contain huge amount of smooth endoplasmic reticulum. Although the amount of cholesterol produced by ER is quite minimal but homeostasis maintenance is the function of smooth endoplasmic reticulum. Movement of molecule to Golgi complex from ER is also another function of smooth endoplasmic reticulum.
i. Lipid Synthesis
The sites where membrane comes in close proximity to other organelles such as plasma membrane, lysosomes, chloroplast, Golgi apparatus and lysosomes and others are the MCS also called the membrane contact sites. Thus, transfer of molecules happen through them. For the production of lipid, in huge amount enzyme are present within the ER to carry out the synthesis.
On receiving a signal, these enzyme start to act and maintain homeostasis, allows the growth and differentiation to occur. Phospholipid’s synthesis safeguards the cell and its content, allows the growth, provides immunity and transfers signal along with transportation of lipid. Between the mitochondria and the ER is the MCS which produces phospholipids.
Another type of lipid are ceramides, produced in the smooth endoplasmic reticulum and are moved to Golgi apparatus. Its functions are cell adhesion, migration, signaling, cell death and cell cycle.
In the smooth endoplasmic reticulum the steroid hormones are formed, however as they cannot be stored in vesicles, hence depending on the requirement they are produced from precursors. smooth endoplasmic reticulum is abundant in testis, ova, hepatocytes and other cells.
ii. Carbohydrate Metabolism
In eukaryotes the source of energy is the carbohydrate. In varying conditions glucose is synthesized from precursors such as pyruvate, lactate, succinate which are non- carbohydrate and the process is known as gluconeogenesis. Although this is a multi-step process.
Glucose-6-Phosphate is the final compound synthesized and cannot pass through the cell and is therefore stored in the cell, thus converting glucose-6-phosphate to glucose by the enzyme present in the smooth endoplasmic reticulum which is glucose-6-phosphatase. Its function are maintaining homeostasis and glucose level and is present in liver and kidney, where the conversion takes place.
iii. Calcium Concentration Regulation
The calcium concentration is regulated by sarcoplasmic reticulum, which is a type of smooth ER. This calcium regulation takes place in the muscle cell. smooth endoplasmic reticulum is the point of entry to the SR and the exit points are the ryanodine receptors along with cisterna.
During the contraction of muscle, calcium is taken out from the SR and moves to the ryanodine reception, thus allowing the contraction to take place. Then again, the calcium is reached to SR with the help of smooth endoplasmic reticulum during relaxation. Thus, acting like a pump and transporting calcium from cytoplasm to the SR and vice-versa.
iv. Drug Detoxification
There are various enzymes present in smooth ER and they are cytochrome P450, which helps in removals of toxins from the liver. The mechanism behind it is to solubilize the drug by attaching a 0H- group so that it can be removed out of the body.
Examples of drug working on the same mechanism are barbiturates and phenobarbital. The detoxification rate can be increased by barbiturates and alcohol; however, this is not possible with small volume of doses, due to wide action of smooth endoplasmic reticulum.
Disorders Caused by Dysfunctional Smooth Endoplasmic Reticulum
i. Cytochrome P450 Oxidoreductase Deficiency
The enzyme present in the smooth endoplasmic reticulum is Cytochrome P450 and its enzyme is Cytochrome P450 reductase and its absence can result in a disorder impacting the production of steroid hormone. It would lead to improper growth, effect on the reproductive system and other issues.
Moderate symptom patient would be infertile, whereas those with severe symptom are impacted with the Antley Bixler syndrome where bones have pre-fused, ears are in lower position, and face is also flattened.
ii. Von Gierke Disease
The disorder is named so due to the person who discovered it in 1929.The disease which has an impact on the metabolism of glycogen is called as Glycogen storage disease (GSD-1). Its symptom are improper growth and blood sugar levels quite low and can be deadly too. Glucose-6-phosphatase is the enzyme which converts glucose-6-phosphate to glucose and the process is gluconeogenesis. This enzyme is found in the smooth endoplasmic reticulum.
The absence of this enzyme can lead to this disorder. In this disorder, due to absence of the enzyme, glycogen cannot be broken thus gets deposited in kidneys and liver and thus increasing the liver size. Out of 100,000 people 1 is affected by this disorder and is an autosomal recessive disorder.
Smooth Endoplasmic Reticulum Citations
- Smooth endoplasmic reticulum and axonal transport. J Neurochem . 1980 Jul;35(1):16-25.
- Is it time to reconsider how to manage oocytes affected by smooth endoplasmic reticulum aggregates? Hum Reprod . 2019 Apr 1;34(4):591-600.
- Endoplasmic Reticulum Stress Induced by Toxic Elements-a Review of Recent Developments. Biol Trace Elem Res . 2020 Jul;196(1):10-19.
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