Target Exam

CUET

Subject

Biology

Chapter

Evolution

Question:

Variation caused by mutation, according to Hugo deVries are :

Options:

Random and directional

Random and directionless

Small and directional

Small and directionless

Correct Answer:

Random and directionless

Explanation:

The correct answer is Option (2) → Random and directionless

In the first decade of twentieth century, Hugo deVries based on his work on evening primrose brought forth the idea of mutations – large difference arising suddenly in a population. He believed that it is mutation which causes evolution and not the minor variations (heritable) that Darwin talked about. Mutations are random and directionless while Darwinian variations are small and directional. Evolution for Darwin was gradual while deVries believed mutation caused speciation and hence called it saltation (single step large mutation).