Nsci 1051: State of the Planet

Exam 1—125 points

1. Just the facts…. (2 points each, 30 points total)

a) How many people are there on Earth today? _________________

b and c) The two primary gases in our atmosphere (and the percentage of total atmospheric composition they represent):

_______ at _______%

d) The amount of carbon dioxide in the atmosphere (include units) ______

e) If you average all the radiation emitted in the universe what color do you get?______

f) According to the weight of scientific evidence, the universe is approximately ______ years old.

g) Also according to the weight of scientific evidence, the earth is approximately ______ years old.

h) Life on land appeared approximately ______ years ago.

j) Tree ferns dominated the earth’s vegetation approximately 350 million years ago. When they died, they were often buried. Today we dig up those tree ferns and use them as ____________________.

k) In class, an article was presented about a worrying pollutant found in the air near the ruins of the World Trade Center. What is that pollutant? _________________

l and m) The two layers of the atmosphere are:

____________________ extending _______ miles above the surface

and..

____________________ extending _______ miles above the surface.

n and o) Plants capture approximately _______ % of available solar energy. The energy captured by plants is then transferred up the food chain to make herbivores (cows, grasshoppers, vegetarians, etc.) with approximately _____ % lost in the process.

p) If a plant (or any other living thing) ceases respiration (stops converting energy rich carbon molecules into usable energy), then the plant is _______________.

2. Describe how the greenhouse effect acts to keep the surface of the earth warmer than it otherwise would be. Include a diagram. (5 points)

3. The Mona Loa curve of atmospheric carbon dioxide is illustrated in the figure below. For 10 points, describe a) the overall trend and factors causing the overall trend and b) the reasons for an annual fluctuation. When is the annual low point for atmospheric carbon dioxide?

4. Describe what happens in photosynthesis. Include the chemical equation, but also describe what happens in plain English. (10 points)

5. I have a jade plant in my house that has been around, living in the same pot, for a number of years now. It doesn’t really get bigger any more, and I bet that if I took it out of its pot, I would find that the pot was pretty much full of roots. The question: is my jade plant a net source of oxygen? Why or why not? (10 points).

6. Explain (include diagrams, but diagrams alone are not sufficient)….

a) Why the equator receives more energy than the poles (10 points)

b) How Hadley cells work to distribute energy away from the equator and how Hadley cells are responsible for the bands of deserts and rainforests seen on the globe. (15 points)

c) Why is England surprisingly warm, while the surf off of warm, sunny Los Angeles is often chilly? (5 points)

7. What three biomes are found in Minnesota? Name them and draw their boundaries? Do the biome boundaries run straight North-South or East-West? Explain why or why not. (10 points)

8. List three factors that have historically determined the prairie-forest border in MN. (6 points)

9. Define Net Primary Productivity (NPP). (3 points)

10. In class, I mentioned the major biomes found in the continental United States. From your reading, describe two other biomes—tell me where the biomes are found and list the characteristics of the dominant vegetation in each of your two biomes. (6 points)

11. Explain the two current theories about what happened to the woolly mammoths of North America. (5 points)

12. EXTRA CREDIT. On my exams, the median score tends to be higher than the mean (average) score. Explain what this means and why it might not be surprising. (5 points)