8th Grade Science

8^th Grade Science 3^rd Nine Weeks Name:

1. Nitrogen is vital for animals in the compositions of amino acids and nucleic acids. From the amino acids they make __ and from the nucleic acids they make __.

(a) DNA; proteins (b) hair; muscle (c) proteins; DNA

2. Photosynthesis in plants produces: (a) O₂ (b) H₂O (c) CO₂

3. Photosynthesis splits which molecule? (a) O₂ (b) H₂O (c) CO₂

4. A cycle involves a given material being:

(a) destroyed (b) created (c) continually reappearing in different forms

5. The ozone layer is important because it:

(a) filters out ultraviolet radiation (b) increases sunlight (c) poisons astronauts

6. Which form of nitrogen is LEAST accessible to plants?

(a) Ammonia (b) Nitrate (c) N₂ gas

7. The most abundant gas in our atmosphere is:

(a) oxygen (b) nitrogen (c) carbon dioxide

8. Water resides longest, on average, in: (a) deep groundwater (b) lakes (c) glaciers

9. Most rain falls over: (a) continents (b) oceans

10. Which material locks up carbon so it is relatively inaccessible to life?

(a) Granite (b) Sugar (c) Limestone (d) None of these

11. Animals carry out respiration using: (a) O₂ (b) H₂O (c) CO₂

12. Hydrologic refers to: (a) O₂ (b) H₂O (c) CO₂

13. About 2% of all water is in: (a) lakes (b) groundwater (c) glaciers

14. The tilt of Earth’s axis causes: (a) Rain (b) Seasons (c) Gravity

15. Area between Earth’s Tropics of Cancer and Capricorn is: (a) tropical (b) temperate (c) polar

16. Now, in the Northern Hemisphere where we live, it is winter. In places south of the equator, such as Australia and parts of Africa and South America, the season right now is:

(a) Spring (b) Summer (c) Fall (d) Winter

17. Heat flows from: (a) high temperature areas to low (b) low temperature areas to high

18. Air moves from areas of : (a) high pressure toward low (b) low pressure toward high

19. Average atmospheric pressure is: (a) 14.7 psi (b) 780 mm Hg (c) 101.3 kPa (d) All of these

20. Atmospheric pressure is greatest: (a) at sea level (b) on the tops of high mountains

21. For a summer night in August, the dewpoint is predicted to be 69° F. The low that night is 73° F. Is the grass wet with dew at 6:00 a.m. the next morning?

22. Which will feel hotter to the average person?

(a) 90 ° F at 90 % relative humidity (b) 90 ° F at 10 % relative humidity

23. The first sign of a warm front moving into a locality is usually:

(a) fog (c) high cirrus clouds

(b) snow (d) a rainbow

24. Falling barometric pressure predicts:

(a) Dry, stable weather (b) Changing weather, often with rain or storms

25. Lines connecting areas of equal atmospheric pressures are: (a) isotherms (b) isobars

26. Major tropical crops, such as bananas and manioc:

(a) do not grow well in cold climates (c) are high in starch

(b) are low in protein (d) all of these

27. All the top 4 food crops are: (a) grains (b) root crops (c) tropical

28. What we know in the USA as corn, the rest of the world calls: (a) maize (b) corn (c) barley (d) wheat

29. Which crop is planted on the most U.S. farmland? (a) Rice (b) Wheat (c) Barley (d) Corn

30. Farming and domestication of plants began about how long ago?

(a) 300 years ago (b) 2000 years ago (c) 10,000 years ago (d) 1 million years ago

31. The majority of landfill wastes in the USA comes from: (a) factories (b) households

32. Sunlight helps the human skin make: (a) Vitamin A (c) Vitamin C

(b) Folic Acid (d) Vitamin D

33. The first plants on a piece of newly cleared ground (whether done by man or nature) will be:

(a) short weedy plants (b) pines (c) hardwoods

34. In Mississippi, pines tend to grow on ___ and hardwoods in wetter low areas.

(a) creek bottoms (b) microdeserts (c) hilltops

35. An archeologist is examining the skull of an ancient person who lived to be over fifty years old. If this person was from a grain-producing agrarian culture, the teeth will most likely be;

(a) perfectly formed (b) extremely worn down (c) cracked open

36. The single most important crop in the world is: (a) Rice (b) Wheat (c) Barley (d) Corn

37. . “Permafrost” is found in: (a) tundra (b) taiga (c) rainforest

38. You would find deer mostly in: (a) tundra (b) temperate deciduous forest (c) rainforest

39. Between tropical rainforest and desert you typically find the:

(a) temperate grasslands (b) temperate deciduous forest (c) savannas

40. Which vegetation type indicates the most rainfall in Mississippi?

(a) Hardwood forest (b) Pine forest (c) Grasslands

41. Most US residents live in which type area? (a) Urban (b) Rural

42. Which type area gets more rainfall? (a) xeric (b) mesic

43. Cities have been termed “population sinks” because:

(a) more people move into cities than out (c) people die younger in cities

(b) people have fewer children in cities (d) all of these

44. The population of the southeastern US is: (a) increasing (b) decreasing (c) not changing

45. Which type egg is most vulnerable to ultraviolet radiation, and the subsequent population decline?

(a) amphibian (b) reptile (c) bird

46. Lays egg with a hard shell to prevent it from drying out: (a) amphibian (b) reptile (c) bird

47. Which juvenile tends to look least like the adult form? (a) amphibian (b) reptile (c) bird

48. Which hatches and spends its early life in water? (a) snake (b) newt (c) crocodilian (d) lizard

49. Charles Darwin formulated his theory of evolution after going to the South Pacific and observing:

(a) apes (b) finches (c) Komodo dragons

50. Which is considered evidence of evolution?

(a) Morphological differences (b) DNA similarities