De Vries gave his mutation theory on organic evolution while working on -
- Althaea rosea
- Oenothera lamarckiana
- Pisum sativum
- Drosophila melanogaster
Answer
(2) Oenothera lamarckiana
Solution
As per NCERT, Hugo de Vries, based on his work on evening primrose, brought forth the idea of mutations — large differences arising suddenly in a population.
⇒ Evening primrose is Oenothera lamarckiana.
⇒ He believed it is mutation which causes evolution (saltation: single-step large mutation).
Answer: (2)