Size: The chromosome size is generally measured during the phases of metaphase in mitotic cell division.
Usually, it measures 0.25µm in birds and fungi, 30µm in certain plants like Trillium and 8 to 12µm inn maize, 3µm in drosophila and 5µm in humans.
While the organisms which are having lesser number of chromosomes have their chromosomes with larger size than the one which is containing higher number of chromosomes.
Where the dicotyledons contains smaller chromosomes comparing with that of monocotyledons.
The animals contain smaller chromosomes on comparing with plants.
The chromosomes are also named depending upon their structure and on which organism it is present as lamp brush chromosomes which is present in few vertebrates and polytene and oocyte chromosomes which are found in certain insects.
Shape: The chromosomes change its shape at different phases during their cell division process.
Where as in the interchange phase the chromosomes look like a thin coiled thread like structures, and on passing to the metaphase and anaphase they become thick and filamented.
These chromosomes also have a centromere (often referred to as clear zone), and kinetochore which forms the length of the chromosome.
The two arms arise from the centromere and they are generally called as chromosomal arms.
However, the position varies accordingly, which results in various shape of the chromosomes as telocentric (centromere is situated at the proximal end), acrocentric (centromere at one end forming long and short arm which form a rod like appearance), metacentric (V- shaped chromosome, where centromere is at the centre), sub-metacentric (j shaped or L-shape where centromere is towards the median position)