somatic cell mutation and a germ cell mutation

According to this theory genetic mutations occur and accumulate with increasing age, causing cells to deteriorate and malfuncti..

The variations at the level of the gene which form the basis of the differences between related organism as well as the diversity among organisms is called gene mutation. Gene mutation is defined as a sudden discrete change in the genetic material of gene which is heritable. ..

They are mutation involving change in number or structure of chromosomes. Change in number of chromosomes induced by mutagens can lead to aberrant gametes, which when fuse with normal gamete lead to aneuploid zygotes. Changes in chromosomal structure by mutation are brought abo..

>Mitosis occurs in all the living cells of the body of an organism. Hence it is called somatic cell division. Mitosis is described as equational division since the chromosome number of daughter cells will be same as that of the parent cell. Mitosis ..

Protoplast is a cell without cell wall. In plants, the cells are invariably surrounded by thick cell wall made of cellulose and pectin. During the process of tissue culture and using it for crop improvement, cell wall acts as a barrier to induce ..

Protoplast is a cell without cell wall. In plants, the cells are invariably surrounded by thick cell wall made of cellulose and pectin. During the process of tissue culture and using it for crop improvement, cell wall acts as a barrier to indu..

This was proposed by Weismann who did not agree with Lamarck's theory of inheritance of acquired characters. To prove his point, he cut off the tails of many successive generations of mice. This resulted in forced disuse of the tail. According to the theory of use and disuse, the tails should have..

Plasma membrane: The permeability of the plasma membrane decreases due to the accumulation of calcium in the membrane. Endoplasmic reticulum: In the cytoplasm of old cells, granular ER decreases. In the nerve cells, nissl granules are decreased. Mitochondria: Mitochondri..

Causes of Cancer - A chemical or other environmental agent that produces cancer is called a carcinogen. The world Health organisation estimates that carcinogens may be associated with 60 - 90% of all human cancer. Depending upon their mode of action carcinogens are of 3 types. (1) Carcinogens that ..

>Culturing of human cells invitro, help in understanding the biochemical basis of inheritance. Human cytology and karyotyping helps in ascertaining the number, shape size and structural features of chromosomes. Study of monogygotic twins helps in distinguishing between hereditary and envi..