Give reasons why acquired characters are not inherited.

Acquired characters are the results of our body’s response to external stimuli such as food, disease, and climate change. This results in the development of a particular trait where a change of phenotype is observed. But for characters to get inherited through generations, the genotype of an organism should be changed. In acquired characters, there is no change in the DNA of germ cells. Hence, acquired characters cannot be inherited.

Acquired characters are traits that an organism develops during its lifetime due to environmental influences, habits, or use and disuse of organs (for example, muscles developed by exercise or scars from injuries). These are not inherited by offspring. The main reasons are:

1. No change in genetic material (DNA)
Acquired characters affect only the body (somatic cells) and do not alter the DNA present in reproductive cells (gametes). Since inheritance depends on genes, and genes remain unchanged, these traits cannot be passed on.

2. Changes are limited to somatic cells
Traits developed during life occur in body cells, not in germ cells (sperm or egg). Only germ cells transmit information to the next generation, so acquired traits are not inherited.

3. Separation of germ cells and body cells
According to the concept of germplasm, there is a clear separation between germ cells and somatic cells. Any modification in body cells does not influence the genetic information of germ cells.

4. Experimental evidence
Experiments like cutting the tails of mice for several generations showed that offspring were still born with normal tails. This proves acquired traits are not inherited.