1. How will Earth's characteristics change if it moved farther from the sun?

A. It would be much colder.

B. It would be much hotter.

C. It would have water in abundance.

D. It would have properties conducive to life.

2. How will the habitable zone be affected if the sun grows bigger and hotter?

A. It will be nearer the sun then be farther from it.

B. It would be farther from the sun.

C. It would not be affected at all.

D. It would be nearer the sun.

3. How does the distance of the planet from the sun affect its ability to support life?       A. Planets that are too near the sun have conditions conducive for life.

     B. Planets that are too far from the sun have conditions conducive for life.

     C. A planet should be not too far nor too near the sun to be able to support life.

     D. There is no relationship between a planet's distance from the sun and its ability to support life.

4. How do plate tectonics enable Earth to support life?

     A. It protects it from solar flares. 

     B. It helps regulate its temperature.

     C. It prevents the burning of its surface.

     D. It protects it from meteoroids and asteroids.

5. How does the presence of the ozone layer contribute to make Earth habitable?

     A. It makes the water cycle possible.

     B. It allows for the recycling of nutrients.

     C. It protects Earth from the Earth's internal heat.

     D. It protects the planet from ultraviolet rays from the sun.

6. Which of the following is NOT a type of life forms on Earth?

      A. Archaea

      B. Asteroids

      C. Bacteria

      D. Plants

7. Suppose someone asks you how Earth can support life, what will be your answer?       I. It has liquid water that is renewable.

     II. Its temperature is very conducive for life.

      III. Its atmosphere is just like the other planets.

      IV. Its magnetic field protects it from solar flares.

A. I and II      B. I, II, and III      C. III and IV          D. I, II, and IV

8. Why is Earth unique?

     I. Earth is not located in the habitable zone.

     II. There are different types of organisms on Earth.

     III. Earth is the only known planet where life forms exist.

     IV. The Earth's atmosphere is very conducive to life's existence.

       A. I and II             B. I, II, and III           C. III and IV             D. II, III, and IV

9. Why is the presence of water on Earth so important to life?

     I. It flows in a natural cycle. 

     II. It is very minimal on Earth's surface.

     III. Many organisms depend on water for survival.

     IV. Earth is the only known planet with water in it.

    A. I and II               B. I, II, and III             C. III and IV             D. I, III, and IV

10.  Which of the following element or compound is the least important to life?

         A. Carbon dioxide

         B. Mercury

         C. Oxygen

         D. Water