Question

Millions of years ago, the ancestors of giraffes had short necks and used to eat leaves from the bushes on the ground. A genetic mutation caused one giraffe's neck to be taller. This long-necked giraffe was able to eat leaves that were higher up on trees. This gave it an advantage as it was able to access more food than other giraffes. Over millions of years, all of the giraffes became long-necked. Which type of environmental factor caused this mutation to be inherited? (1 point) Responses A. food availability B. exercise requirement C. polluted environment D. radiation exposure

Answer 1

A. food availability

Explanation: The long neck became common because giraffes with that mutation had better access to food (a selective advantage) and therefore survived and reproduced more. Radiation or pollution can cause mutations to arise, but the factor that caused the trait to be inherited widely was the selection pressure from food availability.