Explain the mechanism of hereditary change with define heredity ?
Answers
mechanism of hereditary changes- 1. In 1902, Walter and sutton observed the paired chromosomes in the cells of grasshopper; until then it was not known to anyone.
2. research started in the direction of finding the nature of genetic material when it was proved that genes are carried via chromosomes.
3. through which in 1944, trio of scientists ostwald avery, mclyn mecarthy and colin macleod proved that except viruses, all living organisms have DNA as genetic material
Heredity: The process of transfer of traits from parents to the progeny is referred to as heredity.
The transfer of physical and mental characters may take place either through asexual reproduction or sexual reproduction.
The progeny acquire the genetic code of information or DNA of their parents.
Variations because of heredity between individuals can cause species to evolve by natural selection.
Mechanisms:
Mating: The process where the union of the male germ cell spermatozoa with the female ovum takes place.
Growth: The process of repeated division of the zygote.
Chromosomes: The formation of nucleus which carries elementary traits are called as chromosomes.
Gene: The development of a structure that is responsible for the development of a trait.
Chance factor: Only 24 of 48 chromosomes of the sperm or the ovary will form the progeny.