Key for exam 1

1. 65 million years ago

2. ~2500 BC

3. 4.5  to 4.6 billion years old

4. ~12,000 years ago

5. Two of the following

-- Rock layers and fossils from the east coast of South America are similar to the rock layers and fossils on the west coast of Africa.

-- Satellites show that the continents are now spreading apart by 1’’ per year.

-- The sea floor in the center of the Atlantic Ocean is younger than the sea floor near Africa or South America. This suggests it is spreading from the center.

-- Magnetic striping along the mid-Atlantic Ridge show the same pattern as point 3 above.

6. The great majority of the wheat came from CO2 in the air. CO2 is turned into glucose using energy from the sun through a process called photosynthesis. When glucose molecules are connected in a string, cellulose is formed, which is a representative component of plants.

7. Cellulose is a string of glucose molecules. A protein is a string of amino acids. DNA is a string of nucleotide bases.

8. I would compare population trends in populations that have wolves with populations that don’t have wolves. If H1 is true, only the populations with wolves will have declined in the years since wolves were released. If H2 is true, all populations should show a decline because they have shared the same winter climate.

9. The” bottom layers” (as labeled on the figure) were laid down first—on the bottom of the ocean. Then the seafloor was lifted up, the rock layers were tilted onto their side, and the uppermost rocks sheared off by erosion. Then the region was submerged on the bottom of the ocean, and the “top layers” were laid down. Finally, the ocean bottom was once again thrust to the surface..

10. Each three nucleotide bases in the DNA sequence “codes” for an amino acid in a protein. A mutation like the one depicted is likely to cause ONE of the amino acids in the protein to be replaced by another amino acid.

11. CH4 +2O2 —>CO2 + 2H2O Or CH4 +4O —>CO2 + 2H2O

12. There are many possible answers. Here is one:

Lesson: Non-native species introduced into new areas can harm the local species.

 Explanation: Rabbits were intentionally released into Australia to provide hunting opportunities for colonists. The population grew exponentially, became a severe agricultural pest, and helped drive several native species extinct.

13. The population of the United States will double in 70/1 = 70 years, and therefore will equal 600 million people when Jessie is 75 years old.

14. The population of the earth is NOT growing exponentially. If it was, its doubling time would be constant, but the table above shows that the doubling time is decreasing. For example, it took 1400 years for the population to increase from 200 to 400 million people, but only 39 years for the population to go from 3.2 billion to 6.4 billion.

15. Overuse of natural resources can lead to environmental degradation, which can have a devastating impact upon society.