NCERT Question 10 - Chapter 9 Class 10 - Heredity and Evolution

Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?

Answer:

• In asexual reproduction, there is no fusion of gametes , and only 1 parent is involved. So the only reason for variation is errors during DNA copying .
• These variations are very minute and can only be seen over a long period of time since too much deviation can lead to unsurvivable alterations in the genetic makeup for the progeny.
• Sexual reproduction gives rise to more viable variations than asexual reproduction because 2 gametes from different individuals combine to produce an organism. 
• It involves 2 parents so the offspring (child) shows variation due to the presence of characteristics of both parents.
• These variations help adapt to the environment in a better, more efficient manner , and result in evolution and formation of new species over time .