Question 4 - Past Year - 5 Mark Questions - Chapter 9 Class 10 - Heredity and Evolution

(a) What is genetics?

(b) What are genes? Where are the genes located?

(c) State and define three factors responsible for the rise of a new species.

Answer:

(a)

Genetics is the branch of biology that deals with the study of genes and heredity in organisms.

(b)

Gene is a physical and functional unit of heredity made up of DNA . Genes are located in the chromosomes.

(c)

Factors responsible for the rise of a new species are:

• Geographical isolation - New species are formed when the population of the same species splits into 2 separate groups which then get isolated from each other geographically by barriers such as mountain ranges, rivers or sea. 
• Genetic drift - Drastic changes in the frequencies of genes in a small population is called genetic drift. 
• Natural selection - It is the process of evolution of a species whereby characteristics which help individual organisms to survive and reproduce are passed on to their offspring , and those characteristics which do not are not passed on.