What is genetic variation?

• Differences in traits among animals of the same type

• The process of natural selection

• The extinction of a species

• The eruption of a volcano

Why is genetic variation important for survival?

• It helps animals adapt to changing environments

• It causes extinction

• It makes animals identical

• It prevents natural selection

How does natural selection work according to the passage?

• The environment selects traits that help survival

• Animals choose their traits

• Genetic variation is eliminated

• All animals react the same way to changes

What happened to the rock pocket mice after the volcanic eruption?

• Dark-colored mice became more common

• Light-colored mice became more common

• All mice became extinct

• The mice moved to a new area

What is an example of a trait that might help animals survive in a colder environment?

• Thicker fur

• Lighter color

• Slower speed

• Smaller size

What could happen if a group of animals lacks genetic variation during a sudden environmental change?

• They might go extinct

• They will all survive

• They will all adapt quickly

• They will become predators

What does the passage compare genetic variation to?

• Different ingredients to make a cake

• A single type of cake

• A predator in the environment

• A volcanic eruption

According to the text, what happens when the environment 'selects' which traits are most helpful?

• 
  The animals with those traits move to a new place.

• The animals with those traits are more likely to survive and have babies.

• The animals with those traits change their behavior.

• The animals with those traits become sick.

What does the text say can happen if a group of animals does not have enough genetic variation when the environment changes?

• They will quickly adapt to the new environment.

• They might all die, which is called extinction.

• They will start to eat different foods.

• They will grow bigger and stronger

What does the text imply about animals that survive due to natural selection?

• They are always the biggest and strongest.

• They are lucky.

• They have traits that help them in their environment.

• They can change their traits whenever they want.