1. Bellwork Think Link 1-30

2. 1. Every Organism passes on the instruction that specify its traits from one generation to the next. How are these instructions passed on? A. Through discussion B. Through genes C. Through cell walls D. Through books

3. B. Through genes

4. 2. Which of these pulls on Earth with the greatest amount of gravitational force? A. the moon B. the stars C. the sun D. the oceans

5. 3.A fertilized human egg contains 46 chromosomes. How many chromosomes were contributed to the fertilized egg by the mother? A. 92 B. 50 C. 46 D. 23

6. D. 23

7. 4.Which characteristic of an atom determines how it will react with other atoms? A. the arrangement of the protons in the atom. B. the arrangement of the electrons in the atom C. the number of neutrons in an atom D. the mass of the atom

8. B. The arrangement of electrons in an atom

9. 5.What is the major cause of the tides in the Earth’s ocean? A. gravitation pull of the sun and moon. B. revolution of Earth around the sun. C. spinning of Earth on its axis D. gravitational pull of Venus and Mars

10. A. Gravitational pull of the Sun and Moon

11. 6.The last major ice age caused the extinction of some species of plants and animals because they………. A. could not migrate to a warmer part of Earth. B. were able to find different kinds of food. C. were killed off by predators. D. could not adjust to flooding at the end of the ice age.

12. A. Could not migrate to warmer parts of the Earth

13. 7.Why does burning wood produce heat? A. Burning absorbs the mechanical energy contained in wood. B. Burning absorbs the heat energy contained in the wood. C. Burning released the chemical energy contained in the wood. D. Burning releases the electrical energy contained in wood.

14. C. Burning releases the chemical energy stored in the wood.

15. 8.A person pulls on a rope to raise a bucket. The simple machine at the top of the well would be…….. A. makes it harder to use force to raise the bucket. B. increases the weight of the bucket. C. increases the amount of force needed to raise the bucket D. changes the direction of the force used to raise the bucket.

16. D. Changes the direction of the force used to raise the bucket.

17. 9.In ______ reproduction, cells carrying genetic information unite to begin the development of a new individual. A. mitotic B. sexual C. abiotic D. asexual

18. B. sexual

19. 10. An airplane engine burns fuel in order to move the airplane. This causes the airplane to move because _______. A. it increases the force of gravity. B. it decreases the force of gravity. C. it produces a balanced force. D. it produces an unbalanced force.

20. D. It produces an unbalanced force.

21. 11. Plate movement that occurs under the ocean at the boundary of ocean can cause damage to land through____? A. P waves B. seismic waves C. tsunamis D. earthquakess

22. C. tsunamis

23. 12. Bacteria help break down dead plants in compost pile. What kind of factor are bacteria in compost piles? A. biotic B. abiotic C. metric D. electric

24. A. biotic

25. 13. Heat travels from one location to another in predictable ways. Heat from the sun is transferred by ____? A. convection B. conduction C. radiation D. transition

26. C. radiation

27. 14.In which layer of the atmosphere does the weather occur? A. ionosphere B. mesosphere C. stratosphere D. troposphere

28. D. troposphere

29. 15.A carbohydrate is _____. A. a compound B. an element C. a mixture D. a solution

30. A. A compund

31. 16.Vinegar is an acid and baking soda is a base. A chemical reaction occurs when vinegar and baking soda is mixed. A. The chemical reaction produces ice. B. the chemical reaction produces neutral substance. C. The chemical reaction produces unknown elements. D. the chemical reaction produces vinegar.

32. B. The chemical reaction produces a neutral substance

33. 17. Many mountains are sharp and jagged, but the Appalachian Mountains are rounded. What forces have acted on the Appalachian Mountains to give them the rounded shape? A. weathering B. volcanic eruption C. earthquakes D. tsunamis

34. A. weathering

35. 18.Speed equals distance divided by time. S=d/t Joseph traveled 100 miles in 2.5 hours. What was his speed? A. 4 miles per hour B. 25 miles per hour C. 40 miles per hour D. 250 miles per hour

36. C. 40 miles per hour

37. 19.Which substance will not break down during normal laboratory reactions, such as heating, exposure to electric currents, or reaction with acids? A. mixture B. chemical compound C. gelatin D. chemical element

38. D. Chemical element

39. 20. Soil is partially made up of weathered rocks. Which of the following is NOT a way that rocks are weathered? A. water dissolves minerals that hold rocks together. B. acid rain wears away rocks. C. bacteria decompose the minerals in rocks. D. Water freezes in cracks and breaks rocks.

40. B. Acid rain wears away rocks

41. 21. The number of insects in an ecosystem is determined by several factors. These factors keep insect populations in balance. Which factor would not affect the growth of insect populations in an ecosystem? A. number of birds and other predators in the ecosystem. B. slow erosion of the land forms in the ecosystem. C. seasonal climate changes in ecosystem. D. amount of food for insects in the ecosystem.

42. B. Slow erosion of the land forms in the ecosystem.

43. 22.Energy entering ecosystem as sunlight is changed by producers into chemical energy through ________. A. convection B. photosynthesis C. decomposition D. osmosis

44. B. Photosynthesis

45. 23.Which of these have the greatest effect on Earth’s climate because they hold such a large amount of heat? A. oceans B. rivers C. trees D. continents

46. A. Oceans

47. 24.Which of these is an abiotic factor in an habitat? A. climate B. predators C. prey D. camouflage

48. A. climate

49. 25. The chemical formula for sulfuric acid is H2SO4. How many different elements make up sulfuric acid? A. 8 B. 7 C. 3 D. 2

50. C. 3

51. 26.If the bird population suddenly decreased, the population of snakes would also decrease because the snakes would _______. A. not be able to feed on the mice population B. face a reduction in their food source. C. face increased predation by the eagle. D. be eaten by the fish population.

52. C. Face increased predation by the eagle.

53. 27. Which of the following is an example of sexual reproduction? A. some yeast undergoing budding B. a sponge forming from a piece of parent. C. an amoeba undergoing fission. D. a bullfrog fertilizing egg in a pond.

54. D. A bullfrog fertilizing eggs in a pond

55. 28.Which of the following provides the MOST information about environmental conditions on Earth in the time periods before humans appeared. A. the molecular structure of rocks and minerals that formed during that time. B. the fossils left behind by plants and animals that lived during that time. C. the arrangement of the continents during that time. D. the relative density of Earth’s layers during that time.

56. B. The fossils left behind by plants and animals during that time.

57. 29.Below is a diagram that shows the amount of energy available in the organisms of a food web. Organisms in level 1 provide the greatest amount of energy to the other organisms in an ecosystem. In which level of the pyramid do the top predators in a food web belong? A. level 1 B. level 2 C. level 3 D. level 4

58. D. Level 4

59. 30. What type of rock is produced by magma in Earth’s mantle moving into the crust? A. igneous B. metamorphic C. synthetic D. sedimentary

60. B. Metamorphic