Name______________________________

Period_____

6.2 Guided Reading

Natural Selection

As you carefully read through the text, answer the following questions as completely as possible!

Introduction

1. Explain how the deer mouse pictured in the textbook is well adapted for life in the forest.

Natural Selection

2. How are inherited traits different from acquired traits?

3. What are inherited traits influenced by?

4. Does natural selection affect inherited or acquired traits? Explain.

5. Natural selection explains how organisms in a population develop ________________ that allow them to ____________________ and ___________________.

6. Natural selection means that traits that offer an _______________________ will most likely be passed on to the offspring.

7. What are adaptations?

8. List the three components of when natural selection occurs.

9. In terms of natural selection, explain how fur color affects the Arctic Fox.

Mutation

10. How do we get variation among a population to occur? Explain.

11. Mutations are always harmful, sometimes they can be ________________, and sometimes we don’t even notice they have happened.

12. What can happen if a harmful mutation occurs? Explain.

13. What can happen if a mutation is helpful? Explain.

14. A mutation occurs when there is a change in the organism’s ____________ sequence.

15. Our DNA is what makes up our _______________ and determines our phenotype.

16. If there is a change in our DNA sequence it can create drastic changes tour ___________________ and phenotype.

Why so Many Species?

17. Scientists estimate that there are between _______ million and _______ million species on the planet.

18. As environments change over time, organisms must constantly _______________ to those environments.

19. _________________________ increases the chance that at least some organisms adapt and survive any major changes in the environment.