Biology Principles of inheritance and variation class 12

In this course we will learn about Brief concept of inheritance and variation Genetics • Organisms reproduce- formation of offspring of the same kind. • The resulting offspring most often do not totally resemble the parent. • Branch of biology that deals with the inheritance and variation- Genetics. • Inheritance- the process by which characters are passed on from parent to progeny. • Variation-it is the degree by which progeny differ from their parents.

•   history • Human knew before 8000- 1000 B. C variation is due to sexual reproduction • Exploited variations present in wild         plants & animals to selectively breed & select organism with desirable characters • Artificial selection & domestication of   wild cow- Sahiwal cows in Punjab

1. Genetics is the branch of life science that deals with the study of heredity and variation. • Heredity is the transmission of characters from parents to their offsprings. • Variation is the difference among the offsprings and with their parents. • Hereditary variations: These are genetical and inheritable. • Environmental variation: These are acquired and non inheritable. Terminology

2. Gregor Johann Mendel: Father of Genetics • Known as the father of modern genetics • Gregor Mendel developed the principles of heredity while studying seven pairs of inherited characteristics in pea plants. • Although the significance of his work was not recognized during his lifetime, it has become the basis for the present-day field of genetics. and much more concepts.