2. A change in ocean current causes the climate on an island to become drier. As a result, the grasses that cover the island change from dark green to light brown. Over time, how might a species of grass toads that hide in the grasses and are subject to predation respond to these changes?

3. Their coloration will change to brown.

4. A river caused one population of giraffes to become separated into two populations. Members of these two populations were later brought together but were not able to breed. What is this an example of?

5. Speciation

6. A storm blew several butterfly- eating birds to a distant island. The island, which previously had no birds, was filled with butterflies of all colors. One year later, all of the butterflies were dark green and brown. What is likely the explanation for the change in the butterfly population.

7. The surviving butterflies had a trait that protected them from the birds.

8. Over time, animals may change behavior or physical appearance in response to changes in the environment. What is this called?

9. Adaptation

10. What is the process by which individuals that are better adapted to their environment survive and reproduce more successfully than others do?

11. Natural Selection

12. When an effective insecticide is used on a population of insects, most of the insects are killed. However, a few may survive due to genes that make them resistance to the insecticide. What is the BEST explanation of why this occur?

13. Insects that survived sprayings passed their resistance genes to their offspring.

14. When penicillin was first developed it was hailed as a miracle drug. People said that bacterial diseases would be completely wiped out. However, over time many of these species of bacteria are no longer killed with penicillin. What is one likely cause of this phenomenon?

15. Rapid bacterial mutations due to environmental pressures

16. What are organisms that get energy by breaking down the remains of dead organisms called?

17. Decomposers

18. What is a biotic part of the a desert?

19. Anything Living

20. What is the environment in which an organism lives called?

21. Habitat

22. What symbiotic relationship is characterized by organisms that help other?

23. mutualism

24. How many chromosomes will be unable to do what?

25. Produce offspring

26. How many chromosomes are presented in a normal human sex cell?

27. 23

28. How would a gene be described?

29. As the code instructions for a trait

30. if the body cells of an organism have 10 chromosomes, then the sex cells produce during meiosis would have

31. 5 chromosomes

32. On what structure are genes found?

33. chromosomes

34. The function of chromosomes is directly related to which of the following?

35. Passing trait

36. What is heredity?

37. Traits passing from parents to offspring

38. What makes up chromosomes?

39. Many genes joined together

40. How can the process of meiosis be described?

41. Reducing the number of chromosomes by one half

42. Mitosis produces __________________while meiosis produces ________________.

43. Body cells Sex cells

44. Unlike mitosis, what is the end result of meiosis?

45. Four genetically different cells are form

46. What is the haploid number of chromosomes for a human sperm or egg cell?

47. 23

48. What is the number of chromosomes for in a body cell (somatic) known as?

49. diploid

50. What occurs in meiosis, but not in mitosis?

51. Gametes (sex cells) are made

52. How is DNA like RNA? How is different?

53. Answers will vary

54. If a scientist is trying to decide if a molecule is a RNA or DNA, for what should he test?

55. thymine

56. In DNA, what can be said about the amount of thymine (T) as compared to the amount of adenine (A) and the amount of cytosine (C) as compared to guanine (G)?

57. There is an equal amount of thymine and adenine; there is an equal amount of cytosine as guanine. (A always pairs with T; G always pairs with C)

58. What type of mutations has occurred if a DNA sequence that initially reads ATTGCCGAT now reads ATTGCCAT after being copied?

59. Deletion

60. What type of mutation has occurred if a DNA sequence that initially reads ATTGCCGAT now reads ATTGCCAGAT after being copied?

61. Insertion

62. When does a mutation occur?

63. When there is a change in the order of the bases in an organism’s DNA

64. A per plant has alleles for green and yellow seed colors. According to Mendel’s law of segregation of characteristics, what must a gamete of the plant carry?

65. Only one allele

66. A pea plant has white flowers and yellow seeds. What does Mendel’s law of independent assortment say about these traits?

67. Inheritance of one trait does not affect the other.

68. A poodle with black fur (BB) is crossed with a poodle with brown fur (bb). Using a Punnett square, what is the probability that the offspring will be black?

69. 100%

70. All characteristics are determined by what?

71. A minimum of 2 genes.

72. Alleles for different traits are distributed to sex cells and offspring independently of one another. This is an example of which of Mendel’s laws?

73. Independent Assortment

74. An organism with the geneotype Dd is crossed with an organism of the same geneotype. Using a Punnett square, what is the ratio of offspring displaying the recessive allele?

75. During the formation of gametes, the two alleles responsible for a trait separate from each other. Alleles for a trait are then “recombined” at fertilization, producing the geneotype or the traits of the offspring. This is an example of which of Mendel’s laws?

76. Segregation

77. If two first-generation self-pollinating plants are crossed, Pp by Pp, what is the probability that offspring plants will show the recessive trait, pp?

78. 1/4

79. If you cross two rabbits that have the geneotype Bb, how many possible genotypes can be found in the offspring?

80. Three

81. In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation. Offspring that are hybird for a trait will have only the dominant trait in the phenotype. This is an example of which of Mendel’s laws?

82. Dominance

83. In a plant, tall (D) is the dominant allele. Short (d) is the recessive allele. Which GENOTYPE would a short offspring have?

84. dd

85. The likelihood that an offspring will have a genetic disorder, such as sickle cell disease, depends on what factors?

86. The traits passed on by the parents

87. What are the possible genotypes of the offspring if you cross a white flower( with the genotype pp) with a purple flower( with the genotype PP)?

88. All Pp