Answer:
A question is never clear
Answer:
Kettlewell thought that if natural selection caused the change in the moth population, the following must be true: Heavily polluted forests will have mostly dark peppered moths. Clean forests will have mostly light peppered moths. Dark moths resting on light trees are more likely than light moths to be eaten by birds.
It was used till the 1960s. Hope i helped.
Protects the growing tip of the plant
