lysosomes,cytoskeleton,...

ü     Significance of Lysosomes

1       In WBC or leucocyte: Cell of leucocyte digest foreign protein, bacteria and viruses.

2.       In autophagy: During starvation, the lysosomes digest stored food contents such as proteins, fats and glycogen of the cytoplasm and supply the necessary amount of energy to the cell.

3.       In metamorphosis (Frog): During the transformation of a tadpole into frog, the embryonic tissues such as gills and tails are digested by the lysosomes and utilized by other body cells.

4.       In Fertilization: The lysosomal enzymes present in the acrosome of sperm cells digest the limiting membrane of the ovum (egg) Thus, the sperm cell is able to enter the ovum and start the fertilization.lysosome information

ü     Cytoskeleton

Recently complex networks of fibrous protein structures have been shown to exist in the cytosol of eukaryotic cell. These networks collectively form cytoskeleton, which contains three types of protein fibres:

1.       Microtubules(of tubulin protein),

2.       Microfilaments(of actin protein),

3.       Intermediate Filaments (of Keratin and other types of protein).

                                        These fibrous proteins help in cellular movement i.e., amoeboid movement and cyclosis. They also help the cells to maintain their shapes.cytoskeleton

ü     Significance of Diploidy

Diploid state of organism is originated during process of fertilization of sexual reproduction. During fertilization, two haploid cells or gametes of different types: sperm of man and ovum of women are fused together to form a diploid egg (zygote). This egg divides by mitotic cell divisions to form numerous diploid body cells, making the body of diploid organism.

ü     Cell Terms

1.       Protoplasm: The contents of a living cell, contained within the plasma membrane, form protoplasm. Protoplasm is usually differentiated into the nucleus and the cytoplasm.

2.       Gene:  It is a distinct unit of hereditary information. Gene is inherited from one generation to next and determines an observable characteristic or trait of an organism. Genes have to carry coded information of parents to their children or progeny, so that children remain exactly like their parents. Generally a gene is made up of DNA molecule, but sometimes it is made up of RNA molecule as observed in Tobacco Mosaic Virus(TMC)

3.       DNA: Deoxyribonucleic acid; a polymeric nucleic acid.

4.       RNA: Ribonucleic acid; a polymeric nucleic acid.

.