Cell Biology and Structure

Tau proteins are proteins that stabilize microtubules. They are abundant in neurons in the central nervous system and are less common elsewhere. When tau proteins are defective, and no longer stabilize microtubules properly, they can result in dementias such as Alzheimer's disease.

DNA (Deoxyribonucleic Acid) is present in chromosomes, which are located in the nucleus of eukaryotic cells. Chromosomes carry genetic information. Option B is correct.

Egg pro-nucleus with cytoplasm is present at animal pole.

Polar bodies are haploid.

Differential centrifugation—The separation of mixtures such as cellular particles in a medium at various centrifugal forces to separate particles of different density, size and shape from each other.

A fibroblast is a type of cell that synthesises the extracellular matrix and collagen, the structural framework (stroma) for animal tissues and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.

Osteoblasts are bone cells that are responsible for the formation of new bone. The osteoblasts are much smaller; they only have one nucleus. Osteoblasts also work in groups to form new bone. Osteoblasts are important because it allows the bones to be made, remodeled and repaired.

Sieve tube is an organised and differentiated cellular structure having cytoplasm without any nucleus. However, nucleus is present in young cells, but mature sieve tube element lacks nucleus. Its functions are controlled by the nucleus of companion cells.

Regeneration is specifically carried out by specialized cells (often called neoblasts in planaria or stem cells in other organisms) that can dedifferentiate, proliferate, and redifferentiate into needed cell types. Broken cells are damaged beyond function, all cells lack regenerative capacity, and differentiated cells have limited ability to change fates.

Neuron has a branched structure.

Endometrium is the only human tissue that completely regenerates after disruption and interruption of morphology.

Nerve cells do not have the ability to regenerate.

An increase in the number and size of cells is called multiplicative growth.

Epimorphosis is a kind of regeneration that makes the use of remainder piece of part to replace the lost part

Chloroplast is the pigment bearing cell organelle which produces ATP with the help of light energy. Hence, the ATP production in chloroplast is referred to as photophosphorylation.