More Than One Answer Can Be Correct.
Which of the following statements describes an example of natural selection?

An aloe vera plant possessing a trait for extra thick leaves survives a long drought in a desert, while an aloe vera plant that has thinner leaves does not.
A species of corn is genetically modified to produce a natural insecticide, resulting in an increased harvest.
A farmer breeds a certain cow that produces large quantities of milk in order to produce more cows with the same trait.
Owls sleep during the day, while many other animals sleep during the night.

Question

More Than One Answer Can Be Correct.
 Which of the following statements describes an example of natural selection?

An aloe vera plant possessing a trait for extra thick leaves survives a long drought in a desert, while an aloe vera plant that has thinner leaves does not.
   A species of corn is genetically modified to produce a natural insecticide, resulting in an increased harvest.
   A farmer breeds a certain cow that produces large quantities of milk in order to produce more cows with the same trait.
   Owls sleep during the day, while many other animals sleep during the night.

alison123 · Answer

natural selection is something that occurs in nature on its own, so the choices when the substances are being manipulated are gone (b and c). Natural selection occurs when a species ends with an advantage or disadvantage and usually ends up impacting the survival and reproduction of that species. a is the only one that fits that