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Adaptation: Definition, Meaning, and Examples
Continue ReadingAdaptation Definition
Adaptation refers to the process of changing behaviour, physiology, or structure to become more adapted to a given environment in biology and ecology. It may also be described as the condition attained by a biological population that is experiencing modifications or adjustments. It might also refer to a feature that helped the species adapt to its surroundings. The adaptable characteristic is the name given to this personality feature.
What is Adaptation?
The word “adapt” comes from the Latin “adaptus,” which means “I fit” or “I adjust to.” It’s a term used frequently in ecology and evolutionary biology. The organism tends to adapt in order to better suit or match its surroundings. Adaptation is not the same as acclimatisation. Both words refer to the process of transformation. Acclimatization, on the other hand, is the physiological adjustment to new conditions; it does not, however, imply an increase in species variety, as adaption does. A characteristic must be heritable, functional, and enhance fitness to be called an adaptation.
The creatures adapt to their environment in order to survive and pass their genes on to the next generation, according to Charles Darwin’s theory of evolution by natural selection. Several species in the environment co-adapt and, as a result, co-evolve. Take the symbionts in a lichen relationship, for example. Because the absence of one implicates mortality, the algal and fungal components prefer to co-evolve. They must adapt and survive together, since they are reliant on one another’s survival.
Adaptations are necessary for the survival of a species. The species’ adapted characteristics may be structural (i.e. physical adaptive qualities), behavioural (e.g. vocalisations, courtship rituals, nesting, and mating), or physiological (e.g. vocalisations, courtship rituals, nesting, and mating) (e.g. developing resistance to diseases or to toxic chemicals).
Other Definition of Adaptation
Adaptation in neurology refers to a decrease in the frequency with which a neuron fires. It is the capacity of the eye to adapt to varied light intensities by controlling the amount of light entering the eye through the pupil in ophthalmology.
Adaptation Citations
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Cell: Definition, Types, Functions, and Diagram
Continue ReadingWhat is Cell?
The word cell originates from a Latin word which means a small room. Cell is the basic fundamental unit of life, present in living organism. Cell has various organelles within multi-celled organism and single-celled in unicellular organism to perform various function. It can replicate on its own. A cell can be a prokaryotic as well as eukaryotic.
Type of Cell
Cells can be classified in two ways such as unicellular, multicellular and acellular. Another classification type as a prokaryote and eukaryote.
Prokaryotic vs Eukaryotic Cell
An organism is said to be prokaryotic if it lacks nucleus and various other organelles. A eukaryotic cell contains nucleus and organelles such as endoplasmic reticulum, mitochondria, chloroplast, vacuoles, lysosomes, Golgi apparatus and others. Nuclear membrane is another layer surrounding the nucleus and separating the inner contents from the outside. However there exist similarities between the two like the storage of genetic materials which gets copied and then reaches the ribosomes where it gets translated into proteins.
Unicellular vs Multicellular vs Acellular
Organism can be classified as unicellular or multicellular on the basis of the number of cell it contains. Single-celled organisms are called Unicellular. Organisms with multi-celled are multicellular. Unicellular organism examples are prokaryotes. In prokaryotes the example is protist. Example of multicellular organisms are plants and animals.
When various cells comes together it forms tissue. Epithelial tissue, Meristematic tissue, Vascular tissue, Nerve tissue, Muscle tissue, Connective tissue and Sporogenous tissues are the types of tissue. Fundamental and complex are the types of tissue. Example of fundamental tissue are parenchyma, sclerenchyma and others. Complex tissue are phloem and xylem. Cells forms tissue and tissue forms organ when many tissue come together and work.
Acellular refers to something that is not formed from cell. example hyphae.
Structure of Cell
Cell contains various structures which are compartmentalized in it and each one of them has several functions to perform. The very first outer layer is cell membrane which is made up of phospholipids. The function of cell membrane is to keep the outer and inner content separate.
On the surface of the cell membrane are molecules present, which play a role in cell recognition. Cell wall is also present in plants, animal, fungi, algae and few prokaryotes, which is present outside the cell membrane. It keeps the cell rigid, protects it from outer environment. The cytoplasm present in the cell, inhabiting near the organelles, consist of cytosol, a liquid solution made up of ion such as chloride, sodium, water and biomolecules such as carbohydrate, protein and others. Cell signaling, action potential and other reactions take place in the cytosol.
Bacterial Cell Diagram
Eukaryotes are quite organized, due to the presence of various organelles. Eukaryotic cells various organelles are Mitochondria, Endosomes, Golgi apparatus, Endoplasmic Reticulum, Vacuoles, Lysosomes and Cytoskeleton. The function of Endoplasmic reticulum is to clear the drug, metabolism of carbohydrate and synthesis of biomolecules. Glycosylation, lipid transportation within cell, lysosomes arrival and packaging various molecules are functions of Golgi apparatus.
Animal Cell Diagram
The powerhouse of cell is the mitochondria which will provide energy for various process. Plastid example chloroplast which produces and stores food, as they contain chlorophyll which helps in carrying out photosynthesis. The shape of the cell is maintained by the cytoskeleton. The unwanted components are thrown and the reusable ones are recycled by lysosomes.
Plant Cell Diagram
For digestion, excretion, secretion and storage inside the cell vacuoles are important. Cytoplasm contains cytosol made up of proteins, ions and water. Apart from the DNA present in the nucleus, there are DNA found in the mitochondria as well as chloroplast. They carry out various metabolic functions. Both of them are semi-autonomous. Chloroplast DNA is not found in all types of eukaryotic cell as only plants and algae possess chloroplast. Plants possess cell wall which protect them from the outer environment and provides rigidity and shape. The cell wall is surrounded by cell membrane, which is a barrier separating outer contents from the inside. As animal cells do not contain cell wall, they are more flexible.
Although, a prokaryotic cell does not have organelles it has other structures such as Carboxysome which fixes carbon content. Magnetosomes which are seen in magneto tactic bacteria. They also have chlorosomes which are green sulphur bacteria, which harvests light. The DNA is present in a nucleoid region in the prokaryotes.
Features of Cells
i. Cell Cycle
In cell cycle, the DNA get copied, replicated and there is cell division of parent cell to form daughter cell. Thus, it involves division and the growth of the daughter cell. there are various phases in cell cycle such as the interphase, resting phase and others. Cell grows in size, makes copy of its DNA for the division to take place. Before the interphase is the resting phase where the cell is in a dormant stage. G1, S and G2 are the phases of interphases. Thus, leading to completion of cell cycle.
ii. Cell Division
In this process, offspring i.e., the daughter cells are obtained from the parent cell. Mitosis and Meiosis are the cell division process in eukaryotes. Cell division is a very important step as it helps to reproduce, after which the cells grow. The end-product of meiosis is four un-identical cell. the end-product of mitosis is two similar cells.
iii. Cell Growth and Metabolism
While the cells grow, they undergo metabolism. Metabolism is of two types; Catabolism and Anabolism. The process where larger molecules are broken down into smaller molecules is called as Catabolism. With the help of smaller molecules, preparing a larger molecule and requires energy in the form of ATP is called as Anabolism.
Molecules present inside the cell are stored and degraded such as proteins, lipid, carbohydrate and others. The DNA and RNA synthesis site is nucleus. Ribosomes synthesize proteins, whereas in endoplasmic reticulum, lipid is synthesized.
iv. Motility
Motility basically means movement. For the movement of organism, they possess flagella. In structure they are thin long extensions. It is not always necessary that they are used for movement only. They could be used as a signal source as well as for sensation. E.g., olfactory receptor neurons present in the nose, in the eye rod photoreceptor cells.
On the surface, presence of hair like projections are cilia. They are of two types; motile and non-motile. Non- motile play a role in sensory and motile cilia play a role in locomotion. Example are protozoans. Another example is the lining of the lung to throw-off dust particles contain cilia.
Cell Citations
- The impact of cell structure, metabolism and group behavior for the survival of bacteria under stress conditions. Arch Microbiol . 2021 Mar;203(2):431-441.
- Tight Junction Structure and Function Revisited. Trends Cell Biol . 2020 Oct;30(10):805-817.
- Rethinking cell structure. Proc Natl Acad Sci U S A . 1995 Jun 6;92(12):5251-7.
- Shedding light on the cell biology of extracellular vesicles. Nat Rev Mol Cell Biol . 2018 Apr;19(4):213-228.
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De novo: Definition, Meaning, and Examples
Continue ReadingDe novo Definition
The phrase can be used as both an adverb and an adjective. It is used as an adverb to indicate that something occurred from the beginning or from the beginning again. It’s an adjective that describes something that hasn’t existed before or is just getting started.
De novo is a term used in biology to indicate a biological process or entity that has started all over again. It’s a phrase that means “new” or “anew” in English. Medical and other similar areas have the same connotation. Some individuals use italics to signify that the term is a Latin phrase.
De novo Etymology
De novo is derived from the Latin adverb de novo, which means “new.” Specifically, de signifies “from,” but novo implies “new.”
De novo Examples
The following are some examples of its application:
De novo synthesis (of a complicated molecule) is a term used frequently in biochemistry. It refers to the metabolic pathway that leads to the synthesis of any of the numerous complex biomolecules from simple molecules or precursors. This indicates that it was created from scratch within the body.
De novo peptide sequencing is a term used in bioinformatics to describe a type of sequencing.
De novo mutation is a term used in genetics to describe a type of genetic mutation that develops in a family member for the first time. The mutation (e.g., deletion) could result in variants in one of the parents’ germ cells. A faulty gene inside the fertilised egg could possibly be the source of the variation. This type of mutation is critical. They promote gene pool variety by allowing new features to be passed down across generations, resulting in more diversity.
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Ecological Niche: Definition, Meaning, and Examples
Continue ReadingEcological Niche Definition
A niche is a hole, hollow, or recess, especially in a wall, in the broadest meaning. In biology and ecology, however, a niche refers to (1) the specific region in which an organism lives, (2) the role or function of an organism or species in an ecosystem, or (3) the interaction of a species with all the biotic and abiotic variables that impact it.
Ecological Niche Etymology
Niche (plural: niches) is derived from the Old (and current) French niche, from nichier, which means “to construct a nest,” and is derived from the Latin nidus, or nest.
What is Ecological Niche?
The interaction of a species with all of the biotic and abiotic parameters impacting it is referred to as an ecological niche. However, the concept of niche has evolved throughout time. In 1917, Joseph Grinnell invented the word niche, which he used to describe what is essentially a species’ habitat. Charles Sutherland Elton considered niche to be equal to a species’ location in a trophic web in 1927.
The word niche was coined by George Evelyn Hutchinson in 1958 to define the multidimensional space of resources available to and utilised by a species. Despite the various definitions of niche, it is now widely accepted that it refers to how an organism or a population responds to and changes in competition and resource distribution. It describes an organism’s or a population’s location in relation to other organisms or populations in a given environment.
An ecosystem’s biotic and abiotic variables may have an impact on a niche. However, a species’ niche in a specific ecosystem will influence the characteristics of its habitat, as these characteristics are critical to its existence.
Niche vs Habitat
In ecology, a habitat is the location where an organism or a biological population typically lives, resides, or occurs (or is adapted to do so) (s). A forest, a river, a mountain, or a desert might be the setting. While habitat refers to a physical location, a niche refers to a species’ interaction with ecosystem components. An organism’s niche describes how it lives and survives in its environment.
As a result, a habitat may include numerous niches and be able to support a variety of species at any given moment. The concept of niche refers to a single species as part of a habitat, with all of its biological activity affected by biotic and abiotic variables. Predators, rivals, parasites, commensals, and other living and non-living elements might potentially determine an organism’s niche.
Niche Formation
Abiotic and biotic elements work together to define an ecosystem’s niche. Abiotic variables in an ecosystem, such as temperature, climate, and soil type, aid in the formation of niches, whereas natural selection determines which niches are preferred and which are not. Over time, the species acquires unique characteristics that aid in their adaptation to their surroundings. They might flourish and live-in environments that match their characteristics if they fit in.
Biological limitations, such as predation, competition, and parasitism, may, nevertheless, limit the size of their colonies. Because co-habitats compete for available nutrients, space, light, and other important resources, competition in a habitat might limit a species’ population. Depending on the number of predators and the amount of predation, predation might potentially limit the population of a species.
The existence of parasites that use the species as a host, as well as the sensitivity to disease-causing infections, are all factors that might limit the population of a species. As these elements alter, niches in an ecosystem develop and evolve.
Niche Partitioning
Because niches are species-specific, niche partitioning is described as the process by which natural selection drives competing species into distinct niches. There can’t be two species in the same niche at the same time. However, coexistence may aid competing species in establishing their own ecological niches. They must be able to cohabit in order to minimise competing for limited resources, such as through resource differentiation (or niche partitioning). Otherwise, natural selection will favour one of the two competing species, while the other will eventually go extinct.
In the absence of competition, a species’ core niche is defined as its niche. A realised niche, on the other hand, is the niche that a species has occupied as a result of pressures, such as the introduction of a competing species into its environment. When two species use the same resources or other environmental factors, this is known as niche overlap. Because resources are shared, niches frequently overlap only partially.
In an environment, an empty niche is one that has yet to be filled. The presence of an empty niche, on the other hand, is still a point of contention. Nonetheless, environmental disturbances (for example, forest fires and droughts) and evolutionary events are thought to be plausible sources of empty niches (i.e., when species fail to evolve).
Niche Examples
i. Niche of Beavers
Beavers (genus Castor) are semi-aquatic, nocturnal rodents. Dams, canals, and hotels are among their many accomplishments. The water flow in the river where they dwell might change as a result of this activity, altering both biotic and abiotic elements of their habitat. Other animals living in the watershed may be influenced by the beaver’s role in shaping the ecological characteristics of their surroundings.
ii. Niche of Flightless Dung Beetle
Circellium bacchus, the flightless dung beetle, fills a distinct ecological niche. They eat animal droppings and store them in burrows as dung balls. The eggs are deposited within the dung ball so that when the larvae emerge, they will already have food supplies. The dung beetle’s feeding habits help aerate the soil and reintroduce nutrients back into it.
Ecological Niche Citations
- Microorganisms in sediment microbial fuel cells: Ecological niche, microbial response, and environmental function. Sci Total Environ . 2021 Feb 20;756:144145.
- Major challenges for correlational ecological niche model projections to future climate conditions. Ann N Y Acad Sci . 2018 Oct;1429(1):66-77.
- A checklist for maximizing reproducibility of ecological niche models. Nat Ecol Evol . 2019 Oct;3(10):1382-1395.
- Ecological niche differentiation among anammox bacteria. Water Res . 2020 Mar 15;171:115468.
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Epithelium: Definition, Types, Structure, and Examples
Continue ReadingEpithelium Definition
The word epithelium originates from a Latin word where “epi” means on top and “thele” means nipple. Beneath is the basal layer on which the epithelium rests. Epithelium is a tissue made from epithelial cells, which are tightly packed. It is an animal tissue. It fills up the spaces present in the cavities as well as the surface. Connective tissue, muscle tissue, vascular tissue, nerve tissue and epithelium are the vital animal tissues. Simple, stratified and pseudostratified are the types of epithelium on the basis of the layers present.
Classification can also be done on the basis of shape such as cuboidal, squamous and columnar. Digestive tract and reproductive tract are both lined by epithelial. Its function are absorption, transportation and secretion.
Type of Epithelial Tissue
On the basis of the number of layers, epithelium can be classified into Simple epithelial tissue, which les on the basal membrane and consist of only one layer of epithelial cells.
When there are more layers of epithelial cell present it is called as Stratified epithelium. It provides protection and has other functions.
When there are multiple layers of epithelium it is called as Transitional epithelium which is so called as it changes from squamous to cuboidal.
Epithelial cells consisting of a single layer and are close in proximity to the basal membrane are called as pseudo stratified epithelium.
Special Types
This has two types and they are mesothelium and endothelium. The tissue, explicitly the epithelial, that lines the organs and the body such as the ventral body and the pericardial cavity, pleural cavity and peritoneal cavity is called mesothelium. The epithelial tissue lining the lymphatic and blood vessel is called as Endothelium. However, these aren’t true epithelium as their characteristic are different from the normal tissue.
Structure
Basal membrane distinguishes the connective tissue from the epithelium. The epithelial cells in single layer is called as simple and pseudostratified epithelium. The epithelial cell in multiple layer is called as Stratified epithelium.
Epithelial Cells
The classification is on the basis of shape such as: squamous which are uniform and in thickness are very thin. When their cross-section is viewed, they look polygonal in shape. Rectangular cells which are longer and wider are the columnar epithelial cell. Cube shaped are called the cuboidal epithelial cells. Their length and width is the same.
Basement Membrane
It is a matrix, which is fibrous, extracellular and thin, it lies beneath the epithelial cell. The connective tissue and the epithelial tissue can be distinguished by the basement membrane. Basal lamina and reticular lamina are the layers of basement membrane. From the secretion of connective tissue fibroblast, reticular lamina is made and from the secretions of epithelial cells, basal lamina is formed.
Cell Junction
These are the bridges or the path in between the extracellular matrix and the cell. they are made up of protein complexes. Examples are Desmosomes, Gap junctions, Tight junctions, Hemidesmosomes and adherens junction.
Function
The basic function is to provide protection against radiation, toxins, drying up, physical, chemical stress to the structure present beneath. It inhibits the entry of invaders. For example, whenever we get a cut, the barrier is broken thus allowing pathogens to enter, thus, body starts to treat it through several reactions and get clotting factors to act at the site. Thus, gluing work is done by fibrin. The other functions are absorption, secretion and regulation. Endocrine and Exocrine are the two types of glands. Another function is providing sensation to the skin.
Location
Digestive system, reproductive tract and other organs are lined by epithelial tissue.
Development
There are three germ layers; Ectoderm, Endoderm and Mesoderm. From these three layers, various cells arise. From the mesoderm cell which appear, forms the lining of body cavities. From the ectoderm, forms the epidermis. The digestive tract lining is formed from the endoderm.
Epithelium Citations
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Eukaryotic Cells: Definition, Diagram, and Examples
Continue ReadingEukaryotic Cell Definition
Eukaryotes originates from a Greek word; “eu” meaning good, “well” meaning true and “kauon meaning nut. The basic and fundamental unit of life is the cell, as living entities are comprised of cell. Microorganism are divided into Prokaryotes and Eukaryotes. Organism that do not possess nucleus and lack organelles are called prokaryotes. Eukaryotic cells are those who contains nucleus as well as the organelles. Example of prokaryotes are Archaea and Eubacteria. Eukaryotic organism examples are Algae, Fungi, Plants, Protists and Animals.
What is a Eukaryotic Cell?
Eukaryotes contain a nucleus, which is a huge organelle containing the genetic information. However not all eukaryotes possess nucleus, some of them contain nucleus but loses it for other function such as mammalian red blood cells, have attraction towards the respiratory gases and thus when they mature, are ready to lose their nucleus.
Labelled Animal Cell Diagram
Eukaryotic cells which contain nucleus are called nucleated whereas those who don’t possess nucleus are called anucleated. The DNA found in the nucleus has various function such as metabolism, growth, reproduction, homeostasis, differentiation and death. Thus, the DNA has various functions, it needs to be protected and is encapsulated by another layer surrounding the nucleus, it is called as nuclear envelope, which is double jacketed and separating the outer and the inside content. Although it does have pores on the surface so that molecules can come in and leave after their function is over. After the genetic information is copied by the mRNA and further hands it over to ribosomes, for protein translation.
Labelled Plant Cell Diagram
To the ribosomes is the endoplasmic reticulum attached. Ribosomes are found in both prokaryotes as well as eukaryotes, however they differ in their subunit. Eukaryotic cell has various organelles such as Mitochondria, Endosomes, Golgi apparatus, Endoplasmic Reticulum, Vacuoles, Lysosomes and Cytoskeleton. The function of Endoplasmic reticulum is to clear the drug, metabolism of carbohydrate and synthesis of biomolecules. Glycosylation, lipid transportation within cell, lysosomes arrival and packaging various molecules are functions of Golgi apparatus.
The powerhouse of cell is the mitochondria which will provide energy for various process. Plastid example chloroplast which produces and stores food, as they contain chlorophyll which helps in carrying out photosynthesis. The shape of the cell is maintained by the cytoskeleton. The unwanted components are thrown and the reusable ones are recycled by lysosomes.
For digestion, excretion, secretion and storage inside the cell vacuoles are important. Cytoplasm contains cytosol made up of proteins, ions and water. Apart from the DNA present in the nucleus, there are DNA found in the mitochondria as well as chloroplast. They carry out various metabolic functions.
Chloroplast DNA is not found in all types of eukaryotic cell as only plants and algae possess chloroplast. Plants possess cell wall which protect them from the outer environment and provides rigidity and shape. The cell wall is surrounded by cell membrane, which is a barrier separating outer contents from the inside. As animal cells do not contain cell wall, they are more flexible.
Type of Eukaryotic Cells
Eukaryotic cells can be of two types; Unicellular eukaryotic and multicellular eukaryotic. Examples of unicellular eukaryotic are Protists. Examples of multicellular eukaryotes are fungi, plant and animals.
Eukaryotic Cells Examples
It includes plants, animals, fungi and protist. These organism contain various structures in which various organelles are placed such as mitochondria, vacuole, lysosome, endoplamic reticulum and etc.
Evolutionary Origin
From the prokaryotes, the eukaryotes have emerged is what the Endosymbiotic theory states. This is said because the prokaryotic cell resembles the eukaryotes in terms of organelles and various functions that they carry out. However, it further states that prokaryotes have evolved into eukaryotes. Thus, forming different kingdoms such as Plantae, Animalia, Protist and Fungi.
Eukaryotic Cells Citations
- The Roles of Signaling in Cytoskeletal Changes, Random Movement, Direction-Sensing and Polarization of Eukaryotic Cells. Cells . 2020 Jun 10;9(6):1437.
- The functional role of polyamines in eukaryotic cells. Int J Biochem Cell Biol . 2019 Feb;107:104-115.
- Protein Synthesis Initiation in Eukaryotic Cells. Cold Spring Harb Perspect Biol . 2018 Dec 3;10(12):a033092.
- Cell cycle control across the eukaryotic kingdom. Trends Cell Biol . 2013 Jul;23(7):345-56.
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Genus: Definition, Classification, and Examples
Continue ReadingGenus Definition
A biological genus is a taxonomic rank made up of species having similar characteristics. It refers to a collection of species that are physically or phylogenetically linked.A biological genus is a taxonomic rank made up of species having similar characteristics. It refers to a collection of species that are physically or phylogenetically linked.
Genus Etymology
The term genera comes from the Latin word genus, which means “family.” It can imply “birth,” “descent,” “origin,” “kind,” or “type.” The plural version of the word is genera. As most taxonomic families are made up of many genera, the notion of genera applies to more than one genus.
What is Genus?
A genus is a taxonomic category that ranks below family and above species in biological categorization. A genus is made up of species with similar features. As of 2016, the number of published genus names was estimated to be about 510,000. The Catalogue of Life listed 173,363 approved genus names for living and extinct species in 2018. Genus names with no species for some groupings are also included in their report. The genus is the initial word of a scientific name in binomial nomenclature, with the first letter capitalised. They are italicised or added with quotes (“”) along with the particular epithet, e.g., Homo sapiens or “Homo sapiens.”
Classification System
The systematic categorization of living things based on features, hierarchical, or evolutionary relationships is known as organism classification. One of the most important parts of taxonomy is classification. In order to discover links between and among organisms, researchers look at their morphology, anatomy, physiology, evolution, behaviour, development, and genetics. They are then divided into taxonomic groupings and organised into a taxonomic hierarchy. Domain, kingdom, phylum, class, order, family, genus, and species are the most frequent taxonomic levels.
Genus taxonomy is a level of taxonomy that is typically higher than species but lower than family. Carl Linnaeus, a Swedish botanist, made one of the most important contributions to the systematized categorization of organisms. Linnaean is the term given to the categorization system in which creatures are classified into taxa. He was also the one who invented binomial nomenclature. Organisms are categorised in the Linnaean system based on assumed homologies, or similarities in anatomical, morphological, and physiological characteristics. The more homologous structures organisms have, the more probable they are evolutionarily linked.
The Naming System
The genus is the initial word of a scientific name in binomial nomenclature. The genus name is italicised and capitalised. The lion’s binomial name, for example, is Panthera leo. The genus name, Panthera, is the first component, while the specific epithet, leo, is the second. A taxonomist (a person who is knowledgeable about taxonomy) lends a scientific name to a species. Monophyly, sufficient compactness, and distinctness are required for a genus to be descriptively valuable. Monophyly is described by Willi Hennig, a German biologist, as groupings that share derived features or traits that separate them from other creature groups.
When it comes to appropriate compactness, it indicates that the genus does not need to be too enlarged. In addition, the genus name must be unique in terms of evolutionary important characteristics, including ecology, morphology, and biogeography. The Nomenclature Codes give an ideal standard for genus classification and naming. The common or vernacular name differs from the binomial name. In contrast to the former, which is standardised and widely used, the latter is non-standardized and varies by place.
Genus vs Species
In the biological categorization system, a species of organism is considered the most fundamental unit or category. A group must contain at least two individuals capable of generating viable offspring to be considered a species rank (especially through sexual reproduction). Even if they belong to the same genus, organisms from distinct species cannot usually interbreed since their progeny would be sterile. Those that can reproduce and sire viable children of the same sort would be considered species of a certain group of creatures. As a result, they would share the same DNA, have comparable physical and morphological characteristics, and exhibit communal behaviour.
The rank of species is lower than that of a genus. As a result, a genus is more comprehensive and has a broader reach than a species. Nonetheless, because the genus is below the taxonomic family, it would be less comprehensive than a family, which acts as a unified umbrella for related genera. Certain species, such as variants and formae, can be further split into subspecies (called subspecies). When naming an organism, the genus-species format is required. In binomial nomenclature, the genus is the generic name and the species is the specific name. For instance, Allium cepa is a kind of onion (commonly known as onion). The generic name is Allium, whereas the specific name is Cepa.
Genus and Family
A group of one or more genera is referred to as a taxonomic family. A similar characteristic exists among the genera of a given family. As a result, a family is generally more comprehensive and contains a larger number of species. The genera in a family share similar features because they evolved from the same ancestors. A family is above the genus level and below the order level in the taxonomic hierarchy.
Genus Concept
The basic genus is the representative of a taxonomic family in current biological taxonomy. As a result, the latter is defined by one or more genera within a family. The International Code of Zoological Nomenclature establishes the foundational principles of zoology. As a result, the type genus would be used to designate the family group. For example, the Cricetidae family’s type genus is Cricetus (Leske, 1779) The mallard Anas platyrhynchos is another example. The genus Anas is the type genus for the Anatidae family. Canis lupus (dogs and wolves) are members of the Canidae family. The surname Canis is derived from the generic name.
The genus might be the root, while the family name could be the stem, with names ending in –idae being common. In certain cases, the next major taxonomic level, notably order, is also determined by the original genus. Dogs and wolves, for example, are members of the Carnivora order. A type genus, like a type species, should be assigned a family name. If a specimen is found to be of a different genus, the generic name is renamed to a junior synonym.
Genus Usage
A genus may be accessible or unavailable in zoology. The names provided are genus names that have been published according to the International Code of Zoological Nomenclature (ICZN) and the International Commission on Zoological Nomenclature’s criteria. The names that are not accessible are those that were not published due to noncompliance with the ICZN Code. Other factors include misspellings and a lack of type species. In botany, an available name is one that has been validly published, whereas an unavailable name is one that has not yet been published.
A label, nomen invalidum, is given to an invalid genus name (nom. Inval.). In botany, a valid name is referred to as a right name or current name. It’s possible that the genus name will change throughout time and be replaced by another. When new knowledge becomes available, something occurs. As a result, the previously approved term becomes a synonym. Catodon (Linnaeus, 1761), Cetus (Billberg, 1828), Meganeuron (Gray, 1865), Megistosaurus (Harlan, 1828), Phiseter (Bonnaterre, 1789), Physalus (Lacépède, 1804), Physeterus (Duméril, 1806), and Tursio are some of the synonyms for Physeter (Linnaeus (Fleming, 1822).
In biological taxonomy, a homonym is a name that is shared by two taxa. The ambrosia beetle and the platypus, for example, were given the genus name Platypus. Despite this, the ambrosia beetle was the first to be given the genus name Platypus, while the platypus was later given the name Ornithorhynchus. Because they are both from the Kingdom Animalia, they cannot have the same generic name. However, it is still discouraged to use the same genus for specimens from different kingdoms. There are hundreds of examples of species belonging to the same genus from different kingdoms. Aoutus, for example, is the genus name for both night monkeys and golden peas.
Genus Examples
Homo (Latin for “man”) is a genus of humans that belongs to the Hominini tribe of the Hominidae family, order Primates, class Mammalia. Bipedalism, opposable thumb, possession of a notochord that is later replaced by a vertebral column, live birth, and mammary glands producing breast milk in women to nurture the newly born are the essential characteristics of human species in the genus Homo. Several species are listed in this genus, for example. Only one species, H. sapiens, is still alive today (modern).
The following is a list of human species by genus (genus Homo).
• H. habilis
• H. rudolfensis
• H. gautengensis
• H. erectus
• H. ergaster
• H. antecessor
• H. heidelbergensis
• H. cepranensis
• H. rhodesiensis
• H. naledi
• H. neanderthalensis
• H. floresiensis
• H. tsaichangensis
• Denisova hominin
• Red Deer Cave people
• H. s. sapiens (modern)
These animals have a highly developed brain and sophisticated cognitive abilities, especially in abstract reasoning, problem-solving, self-awareness, and eloquent communication. They walk with an erect carriage on two legs. Their teeth are smaller than those of other primates. These characteristics distinguish them from other genera, such as Australopithecus. Australopithecus is also a member of the Hominini tribe. Their brains were roughly a third of the size of modern humans’ brains. They were typically smaller and shorter than humans (between 3’11 and 4’7). Because their bodies are completely covered in hair, they are more morphologically similar to chimps and bonobos than to humans. However, Astralopithecus had a role in human development.
The genus Homo is thought to have descended from one of this genus’ species millions of years ago. Ardipithecus is another genus in the Hominidae family. This genus has already become extinct. They broke away from the chimps. They have a gripping hallux, or big toe, that allows them to easily travel from one tree to another. It’s debatable if this genus is the oldest human progenitor because they behave more like chimps than humans. Sahelanthropus is a genus of extinct animals that lived during the Miocene era, notably at the time when chimps and humans split.
Genus Citations
- Genus Periploca (Apocynaceae): A Review of Its Classification, Phytochemistry, Biological Activities and Toxicology. Molecules . 2019 Jul 29;24(15):2749.
- The genus Jatropha (Euphorbiaceae): A review on secondary chemical metabolites and biological aspects. Chem Biol Interact . 2020 Feb 25;318:108976.
- The genus Cordyceps: An extensive review of its traditional uses, phytochemistry and pharmacology. Fitoterapia . 2018 Sep;129:293-316.
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Hydrophobic: Definition, Interaction, and Examples
Continue ReadingHydrophobic Definition
Hydrophobic refers to a fear of mixing or interacting with water under a certain set of reaction conditions. Hydrophobicity is a term used in general science to describe a substance’s capacity to resist water.
The name “hydrophobicity” comes from two Greek words: “hydro,” which means “water,” and “phobos,” which means “fear.” As a result, hydrophobic substances are those that commonly display the feature of hydrophobicity.
What is Hydrophobic?
Materials with a special affinity for water – those it spreads across, maximizing contact – are known as hydrophilic. Those that naturally repel water, causing droplets to form, are known as hydrophobic. Nonpolar molecules are those that aren’t polar. Non-polar molecules, in particular, do not seem to have distinct charges, therefore no positive and negative poles are generated. Furthermore, it may be deduced that the electrical charges in non-polar molecules are spread evenly throughout the whole molecule.
Scientists have clearly proven that “like dissolves like.” As a result, hydrophobic compounds are miscible with non-polar liquids, the majority of which are organic solvents. It’s worth noting that, because water is polar, the bond between water and hydrophobic molecules is relatively weak. Aside from hydrophobic materials, the literature mentions a number of superhydrophobic materials.
Super-hydrophobic materials resist wetting because their contact angle with water is more than 150 degrees (the ability of a liquid to maintain contact with a solid surface). The super hydrophobicity of molecules, on the other hand, is a consequence of interfacial tension rather than a chemical characteristic of matter. The Lotus effect refers to the shape created by water droplets on hydrophobic surfaces.
The emergence of water droplets on the surface of lotus leaves is one of the most common examples of the lotus effect, which is also employed in textile manufacturing for self-cleaning purposes. Lacking an affinity for water; insoluble in water; resisting water (biology term). Alkanes, oils, fats, and greasy compounds in general are examples of hydrophobic molecules.
Example of Hydrophobic Substances
Both the household and industrial sectors include a variety of hydrophobic chemicals. Hydrophobic substances include alkanes, oils, fats, greasy chemicals, and the vast majority of organic molecules. The removal of oil from aqueous solutions, the management of oil spills, and the chemical separation process to separate non-polar components from polar elements are all uses of hydrophobic substances. Because water is polar and fats and oils are non-polar and highly hydrophobic, it is a frequent observation that when oil or fats are combined with water, two separate layers emerge that are immiscible with each other.
Animals and plants both exhibit hydrophobicity in different ways. Many plants are hydrophobic by nature, indicating that the leaves have hydrophobic coats on their surfaces. The coating’s primary function is to prevent water and rain from adsorbing into the leaves, which obstructs the passage of nutrients. The movement of nitrites in plants is determined by the flow of water from roots to leaves. As a result, if the leaf surfaces are not hydrophobic, the osmosis process and therefore osmotic pressure will be disrupted, which will have a significant impact on plant nutrition.
The process of hydrophobicity is similarly important in birds. Birds’ hydrophobic bodies and feathers prevent water from penetrating their bodies, preventing excessive weight gain and aiding them in smooth flight.
Hydrophobic and Hydrophilic Substances
Water-loving polar molecules are known as hydrophilic compounds. Sugar, salt, starch, and cellulose are examples of compounds that are easily soluble in water. Hydrophilicity is the degree to which the surface of hydrophilic molecules attracts water molecules. Hydrophobic, on the other hand, is water repellent and, as a result of its non-polar nature, is not miscible in water. Some of the most frequent chemical groups discovered in hydrophobic compounds are-CH3,-CH2-CH3,-R-C6H5 and C2H2, whereas hydrophilic substances include-OH,-COOO-, and-NH-.
Hydrophobic and Lipophilic
The phrases hydrophobic and lipophilic are sometimes used interchangeably, yet the two words refer to completely distinct phenomena. Water repelling compounds are hydrophobic, whereas fat-loving ones are lipophilic. Except for silicones and fluorocarbons, most hydrophobic compounds are lipophilic in nature, according to diverse publications.
Hydrophobic Interactions
Under the umbrella of hydrophobic interactions, the interactions between water and hydrophobes are extensively characterised. A good example of such interactions is the relative mixing of water and fat. The hydrogen bonds in the water molecule break when a hydrophobe is placed in an aqueous solution, however this does not ensure that the water molecule will interact with the hydrophobic materials. Furthermore, heat must be applied to the system in order to break the strong hydrogen bond, making the process endothermic.
Around the surface of the hydrophobe, new hydrogen bonds create an ice-like cage structure known as a clathrate cage. The system becomes more organised when the clathrate cage is oriented in this way, and the total entropy (a measure of disorderliness) of the system decreases. The intensity of hydrophobic interactions is also affected by temperature, the amount of carbon atoms in the hydrophobe, as well as the shape and size of the hydrophobic molecule.
Biological Importance of Hydrophobic Interactions
Protein folding relies heavily on hydrophobic interactions to keep it stable and physiologically active. Proteins will be able to decrease their surface area and avoid unwanted interactions with water molecules as a result of these interactions. Similarly, hydrophobic interactions are essential for the survival and optimal functioning of the phospholipid bilayer membranes found in every cell in the human body.
Advantages of Hydrophobes
Hydrophobic compounds provide several advantages in both home and industrial uses. Hydrophobes are low-energy surface materials that are resistant to wetting and have better corrosion resistance. These chemicals are utilised in moisture detection instruments as well as heat trace tubing and analytical sample transfer systems to prevent moisture contamination. In addition, hydrophobes are used in HPLC medical diagnostics to enhance separation and corrosion resistance. Similarly, anti-biofouling coatings for boots, metal refining, stain-resistant fabrics, oil and water separation in the textile sector, and the manufacturing of fire retardant and waterproof clothing all employ hydrophobic surfaces.
Measurement of Hydrophobicity
Various analytical methods, such as hydrophobic interaction chromatography, contact angle measurement, and rose bengal measurement, can be used to determine hydrophobicity. It’s worth noting that while evaluating hydrophobicity, the identification of groups present in the particle is critical. The most common approach to calculating the hydrophobicity of a surface is to determine the contact angle between the droplets of water and the surface itself. The water droplet running over a hydrophobic surface generally maintains a contact angle of greater than 90 degrees and preserves its spherical form. Furthermore, superhydrophobic materials have a contact angle of greater than 150 degrees.
Water droplets spread out far when they come into contact with hydrophilic surfaces, and the contact angle is usually less than 90 degrees. The angle is less than 5 degrees for super hydrophilic, less than 90 degrees for hydrophilic, and 90-150 degrees and 150-180 degrees for hydrophobic and superhydrophobic, respectively. The higher the contact angle between the water droplet and the hydrophobes, the stronger the liquid-liquid interaction rather than the liquid surface interaction, making the surface hydrophobic.
Conclusion
Hydrophobic substances, in conclusion, are those that are not miscible in water. Non-polar liquids, mostly organic solvents, are miscible with hydrophobes. Because water is a polar molecule, the bond between it and hydrophobic substances is very weak, and when they come into contact, they create two separate and distinct layers. Hydrophobic substances include alkanes, oils, fats, and greasy chemicals. Plants and birds both go through the hydrophobicity process. The hydrophobic coating found on the surface of the leaves, which prevents water from entering through them, prevents the interruption of the flow of nutrients in plants. As a result, water continues to flow from the base to the top of the plant, transporting essential nutrients from the soil to their destination.
Similarly, hydrophobicity prevents water from entering the bodies of birds via feathers, skin, and aquatic creatures, preventing them from becoming overweight and facilitating smooth flight. Furthermore, the contact angle between the water droplet and the hydrophobe’s surface may be calculated to determine hydrophobicity. The water droplet running over a hydrophobic surface generally maintains a contact angle of greater than 90 degrees and preserves its spherical form.
Hydrophobic Citations
- Water Structure and Properties at Hydrophilic and Hydrophobic Surfaces. Annu Rev Chem Biomol Eng . 2020 Jun 7;11:523-557.
- Hydrophobic interaction chromatography. Methods Biochem Anal . 2011;54:165-81.
- Theory and use of hydrophobic interaction chromatography in protein purification applications. Methods Enzymol . 2009;463:405-14.
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Involuntary Muscles: Definition, Types, and Examples
Continue ReadingInvoluntary Muscle Definition
Muscles which are under our control are called as Voluntary muscle, whereas those which cannot be controlled by ourselves are called as involuntary muscle. These muscles are under the control of autonomic nervous system. Functions such as contraction, expansion and other functions are involuntary. An example is heart which is controlled by involuntary muscle. To perform the involuntary action, autonomic nervous system, stimulates the nerves and other signal transferring molecule to carry out the function. However, in other cases stretching of muscle can also trigger contraction.
Involuntary vs Voluntary Muscles
Involuntary muscles are under our control, whereas voluntary muscles are under our control. Examples of involuntary muscles are smooth muscles and cardiac muscle. These two same muscles are also example of voluntary muscle; however, they differ from each other.
Involuntary muscles are related with organs that are involved in contraction, such as heart, respiratory system and digestive system. Voluntary muscles are associated with the skeletal system. Involuntary muscles are also known by the name non-striated muscle or smooth muscle. Striated or skeletal muscles are also called as Voluntary muscle. Location of involuntary muscle is stomach, intestine, hearts cardiac muscle, urinary bladder and blood vessel.
Voluntary muscle are located in the skeletal system. Voluntary muscle do possess Striations, whereas involuntary muscle lacks striations. Around the in-voluntary muscle there is a thin layer of sarcolemma. Voluntary muscle has a thick layer of sarcolemma.
Intercalated disc is not found in voluntary muscle, whereas involuntary muscle does have intercalated disc. Sarcomeres are present in voluntary muscle. Involuntary muscle lacks sarcomeres. Involuntary muscle are under the possession of autonomic nervous system. Voluntary muscle are under the control of somatic nervous system. Involuntary muscle requires less energy, whereas voluntary muscle requires huge amount of energy.
The movement of thus, voluntary muscle is quite quick and thus they get tired very quick, whereas involuntary have slower movements and work continuously. Voluntary muscles are triggered by the fibers of the muscle, whereas the voluntary muscle get stimuli from outside the nervous system. Example of involuntary muscle are respiratory tract, blood vessel and others. Examples of voluntary muscle are biceps, triceps, pectoral muscle and quadriceps.
Involuntary Muscles Examples
There are two types such as Cardiac and Smooth muscle.
i. Cardiac Involuntary Muscle
These are striated muscle present in the wall of the heart which contract and relax. Cardiomyocytes are single heart muscle. Cardiac muscles are formed when intercalated disc are joined by Cardiomyocytes. These muscles are coated with fibers of collagen. As cardiac muscles get stimulus from within the muscle, they are myogenic.
For the cardiac muscle to contract they obtain electrical stimulus. Thus, action potential gets generated and in the sarcoplasmic reticulum, calcium ions get deposited. Due to huge amount of calcium ions, excitation occurs and muscles get contracted.
ii. Smooth Involuntary Muscle
These muscles form a lining to the internal organs such as respiratory, urinary, intestine and blood vessel and they are non-striated. An example is ciliary which regulates iris movement by dilating the eye. It consist of thick and thin filaments and are spindle in shape. When they are observed under microscope, they look uniform, hence the name smooth muscle.
For contraction to happen these muscle contain calcium in the sarcoplasmic reticulum, which increases the calcium levels, thus causing excitation and leading to contraction. They also have actin and myosin in the cytoplasm. They are of two type: single unit smooth muscle which contract and relax together, whereas multi-unit smooth muscle contract and expand differently, as they are not electrically coupled. Example digestive system contraction is an example of single unit muscle.
Example of multi-unit muscle is ciliary muscle in the eye. As they lack sarcomeres, thus they are not quite flexible, however gets relaxed when the muscles organ is stretched, organ fills up. Thus, a stress relaxation response gets created and contraction are induced. However, after contraction when it relaxes, the occupied space within the organ does not empty up prior. This mechanism is seen in the bladder, to ensure smooth functioning of the unwanted products. Thus, the elasticity of smooth muscle is of vital importance.
Difference Between Cardiac and Smooth Muscle
Although cardiac and smooth muscle are involuntary, they do are quite different from each other:
a) Smooth muscles are located in the lining of internal organs, whereas cardiac muscle in aorta and heart.
b) Smooth muscles have the ability to regenerate, whereas cardiac muscle cannot.
c) Smooth muscle is directly under the control of autonomic nervous system, while cardiac muscle are through the cardiac pacemaker.
d) Smooth muscles are non-striated, whereas the cardiac muscles are striated present in the heart.
Involuntary Muscle Function
There are various functions of involuntary muscle and they are:
a) Involuntary muscles of heart pumps blood throughout the body.
b) Due to the elasticity of smooth muscle, it can hold up the urine and other excretory products in the bladder.
c) In the exocrine glands, duct as well, involuntary muscle plays an important role.
d) Involuntary muscle contractions in the digestive tract allows the peristaltic movement in the intestine. Thus, allowing its movement and proper mixing of food in the digestive system.
e) In cold conditions or in fear, involuntary muscle preset on the skin called the arector pili are responsible for goosebumps.
f) For the uncontrollable flow of blood and for maintaining blood pressure, smooth muscles present in the arteries contract.
g) To alter the shape of the lenses, ciliary muscles dilate and contract.
h) The contraction and relaxation of the muscles closes the orifice. Ex uterus.
Involuntary Muscles Citations
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Muscle Cell: Definition, Types, and Examples
Continue ReadingWhat is Muscle Cell?
Any of the mature contractile cells that build up muscle tissue are long and tubular. One of the four basic types of animal tissue is muscular tissue. Muscle tissue is made up of specialised cells that can contract. Muscle cells are the name of these cells (also called myocytes or muscle fibers). Because of its lengthy and tubular shape, the muscle cell is also known as the muscle fibre.
Myogenesis is the process through which myoblasts grow into muscle cells. Myofibrils, which are made up of repeating sarcomere portions, make up the muscle cells. Sarcoplasm is the cytoplasm of the muscle cell. The Sarcoplasmic reticulum is the smooth endoplasmic reticulum of muscle cells. Sarcolemma refers to the muscle cell’s plasma membrane. Skeletal myocytes, smooth myocytes, and cardiac myocytes are the three kinds of muscle cells.
Skeletal myocytes (also known as skeletal muscle fibres) are multinucleated, striated cells that make up the skeletal muscles. Skeletal myocytes have myofibrils that are contained inside and connected to the sarcolemma. Smooth myocytes are striated muscle cells that do not have any ridges. They have a spindle form and are elongated.
A cardiac myocyte is a muscle cell with one or two nuclei and myofibrils that are separated from one another by an intercalated disc. The cardiac myocytes are striated in the same way that skeletal myocytes are. The latter, on the other hand, forms an intercalating network.
Muscle Cell Citations
- Molecular regulation of vascular smooth muscle cell differentiation in development and disease. Physiol Rev . 2004 Jul;84(3):767-801.
- Muscle cell communication in development and repair. Curr Opin Pharmacol . 2017 Jun;34:7-14.
- Smooth Muscle Cell Phenotypic Diversity. Arterioscler Thromb Vasc Biol . 2019 Sep;39(9):1715-1723.
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