Question

The ultimate source of organic variation is
1. natural selection
2. sexual reproduction
3. hormonal action
4. mutation

Answer 1

Correct Answer - Option 4 : mutation

Concept:

• The variations between individuals belonging to the same species are termed Organic or natural variations. These may be caused due to genetic changes or environmental changes

Explanation:

Mutation:

• It is defined as the change of gene sequence in the organism’s genome by deletion, addition, or translocation such that it alters the genetic message carried by that gene.
• Mutations are permanent irreversible inheritable changes i.e. they are carried forward in the next generation & cannot be reversed thus, mutations are referred to as the ultimate source of organic variation 

 

• Natural selection was given by Charles Darwin, according to it those populations which are a better fit (reproductively fit) in an environment will be selected by nature and will survive more.
• Hormones are chemical messengers that the endocrine glands produce & release directly into the bloodstream. Hormones help regulate many bodily processes, such as hunger, sleep, and growth. They are not responsible for natural variations
• Sexual reproduction:  Involves the formation of the male and female gametes, either by the same individual or by different individuals of the opposite sex.