2. 11.1 Work of Gregor Mendel 11.2 Applying Mendel’s Principles 11.3 Other Patterns of Inheritance 11.4 Meiosis 100 200 300 400 500 600 700 800 900 1000 1100 1200

3. 1Each pea-plant gamete has how many alleles for the height gene? A 1 B 2 C 3 D 4

5. 2A mule is the result of a cross between a donkey and a horse. A mule is a A tetrad. B phenotype. C genotype. D hybrid.

7. 3Gregor Mendel removed the male parts from the flowers of some plants in order to A prevent hybrids from forming. B prevent cross-pollination. C stimulate self-pollination. D control crosses between plants.

9. 4If a pea plant has a recessive allele for green peas, it will produce A green peas if it also has a dominant allele for yellow peas. B both green peas and yellow peas if it also has a dominant allele for yellow peas. C green peas if it does not also have a dominant allele for yellow peas. D yellow peas if it does not also have a dominant allele for green peas.

11. 5When Gregor Mendel crossed a tall plant with a short plant, the F 1 plants inherited A one allele from each parent. B two alleles from each parent. C three alleles from each parent. D four alleles from each parent.

13. 6If a pea plant’s alleles for height are tt, what is true of its parents? A Both parents were tall. B Both parents were short. C Both parents contributed a recessive allele. D Both parents contributed a dominant allele.

15. 7When Gregor Mendel crossed true-breeding tall plants with true-breeding short plants, why was it impossible to observe segregation? A Alleles for height do not segregate in the F 2. B Alleles segregate only in the F 2 generation. C Alleles segregate best when two tall plants are crossed. D Alleles in the F 1 must be Tt to have height variety in the F 2.

17. 8A tall plant (TT) is crossed with a short plant (Tt). If the tall F 1 pea plants are allowed to self-pollinate, A the offspring will be of medium height. B all of the offspring will be tall. C all of the offspring will be short. D the offspring can be tall or short.

19. 9In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F 2 generation because A the allele for shortness becomes more common in the F 2 generation. B the allele for shortness becomes dominant in the F 2 generation. C the alleles for both heights segregated when the F 1 plants made gametes. D the alleles for tallness begin to disappear in the F 2 generation.

21. 10When you flip a coin, what is the probability that it will come up tails? A 1 B 1/2 C 1/4 D 1/8

23. 11The principles of probability can be used to A predict the traits of the offspring of genetic crosses. B determine the actual outcomes of genetic crosses. C determine which species should be used in genetic crosses. D decide which organisms are best to use in genetic crosses.

25. 12A heterozygous tall pea plant is crossed with a short plant. The probability that an F 1 plant will be tall is A 25%. B 50%. C 75%. D 100%.

27. 13Organisms that have two identical alleles for a particular trait are said to be A hybrid. B homozygous. C heterozygous. D dominant.

29. 14In the Punnett square shown in Figure 11–1, which of the following is true about the offspring resulting from the cross? A About half are expected to be short. B All are expected to be short. C About three fourths are expected to be tall. D All are expected to be tall. Figure 11 – 1 Tt Tt TT T Tt TTTTt T= Tall t= Short

31. 15What principle states that during gamete formation genes for different traits separate without influencing each other’s inheritance? A principle of dominance B principle of independent assortment C principle of probabilities D principle of segregation

33. 16The Punnett square in Figure 11–2 shows that the gene for pea shape and the gene for pea color A assort independently. B are linked. C have the same alleles. D are always homozygous. RrYy RYRyrYry RYRRYYRRYyRrYYRrYy Seed Shape R = Round r = Wrinkled RrYyRyRRYyRRyyRrYyRryy Seed Color Y = Yellow y = Green rYRrYYRrYyrrYYrrYy ryRrYyRryyrrYyrryy Figure 11 – 2

35. 17How many different allele combinations would be found in the gametes produced by a pea plant whose genotype was RrYY? A 2 B 4 C 8 D 16

37. 18Use Figure 11–3 to answer the following question. If a pea plant that is heterozygous for round, yellow peas (RrYy) is crossed with a pea plant that is homozygous for round peas but heterozygous for yellow peas (RRYy), how many different phenotypes are their offspring expected to show? A 2 B 4 C 8 D 16 RrYy RRYy RYRyRYRy RYRRYYRRYyRRYYRRYy RyRRYyRRyyRrYyRRyy rYRrYYRrYyRrYYRrYy ryRrYyRryyRrYyRryy Figure 11 – 3

39. 19Gregor Mendel’s principles of genetics apply to A plants only. B animals only. C pea plants only. D all organisms.

41. 20Why did Thomas Hunt Morgan use fruit flies in his studies? A Fruit flies produce a large number of offspring. B Fruit flies take a long time to produce offspring. C Fruit flies share certain characteristics with pea plants. D Fruit flies have a long life span.

43. 21 A male and female bison that are both heterozygous for normal skin pigmentation (Aa) produce an albino offspring (aa). Which of Mendel’s principles explain(s) why the offspring is albino? A dominance only B independent assortment only C dominance and segregation D segregation only

45. 22 Roan cattle show codominance for the color of their hair. There are alleles for red hair and white hair. What would you expect a heterozygous roan bull to look like if the trait showed incomplete dominance instead? A It would be red. B It would be white. C It would be spotted. D It would be pink.

47. 23 A breed of chicken shows codominance for feather color. One allele codes for black feathers, another codes for white feathers. The feathers of heterozygous chickens of this breed will be A black. B white. C gray. D speckled.

49. 24 Situations in which one allele for a gene is not completely dominant over another allele for that gene are called A multiple alleles. B incomplete dominance. C polygenic inheritance. D multiple genes.

51. 25 A cross of a black chicken (BB) with a white chicken (WW) produces all speckled offspring (BBWW). This type of inheritance is known as A incomplete dominance. B polygenic inheritance. C codominance. D multiple alleles.

53. 26Variation in human skin color is an example of A incomplete dominance. B codominance. C polygenic traits. D multiple alleles.

55. 27What determines the color of western white butterflies? A genes alone. B the environment alone C temperature and genes D exposure to sunlight and genes

57. 28Which of the following supports the claim that the environment can affect genetic traits? A Oak trees get taller as they grow. B Hydrangea flower color varies with soil pH. C Dandelion plants are self pollinating. D Pinion trees bear cones every other year.

59. 29The arctic fox is blue-gray in the summer and white in the winter. What most likely influence(s) this change? A genes and the environment B dominant alleles C the environment alone D codominant alleles

61. 30The number of chromosomes in a gamete is represented by the symbol A Z. B X. C N. D Y.

63. 31If an organism’s diploid number is 12, its haploid number is A 12. B 6. C 24. D 3.

65. 32 Gametes have A homologous chromosomes. B twice the number of chromosomes found in body cells. C two sets of chromosomes. D one allele for each gene.

67. 33 Gametes are produced by the process of A mitosis. B meiosis. C crossing-over. D replication.

69. 34 What is shown in Figure 11–4? A independent assortment B anaphase I of meiosis C crossing-over D replication Figure 11 – 4

71. 35 Chromosomes form tetrads during A prophase I of meiosis. B metaphase I of meiosis. C interphase. D anaphase II of meiosis.

73. 36 What reduces the number of chromosomes during meiosis? A Crossing-over occurs. B Metaphase occurs. C Replication occurs twice. D Replication does not occur.

75. 37 Unlike mitosis, meiosis results in the formation of A diploid cells. B haploid cells. C 2N daughter cells. D body cells.

77. 38 What is formed at the end of meiosis? A two genetically identical cells B four genetically different cells C four genetically identical cells D two genetically different cells

79. 39 At the end of meiosis, there are A two haploid daughter cells. B four haploid daughter cells. C two diploid daughter cells. D four diploid daughter cells.

81. 40 Which of the following assort independently? A chromosomes B linked genes C multiple alleles D codominant alleles

83. 41 Linked genes A are never separated. B assort independently. C are on the same chromosome. D are always recessive.

85. 42 Which trait is most likely linked to having a curved wing in the fruit fly in Figure 11–5? A dumpy wing B vestigial wing C arc (bent wings) D speck wing

87. 43 Gene maps are based on A the frequencies of crossing-over. B independent assortment. C genetic diversity. D the number of genes in a cell.

89. 44 If two genes are on the same chromosome and rarely assort independently, A crossing-over never occurs between the genes. B crossing-over always occurs between the genes. C the genes are probably located far apart from each other. D the genes are probably located close to each other.

91. 45 The farther apart two genes are located on a chromosome, the A less likely they are to be inherited together. B more likely they are to be linked. C less likely they are to assort independently. D less likely they are to be separated by crossing over.

93. 46A trait is a specific characteristic that varies from one individual to another. _________________________

95. 47True-breeding plants that produced axial flowers were crossed with true-breeding plants that produced terminal flowers. The resulting offspring all produced terminal flowers because the allele for terminal flowers is recessive. _________________________

97. 48During the formation of gametes in a hybrid tall plant, the tall allele and the short allele stay together. _________________________

99. 49If the alleles for a trait did not segregate during gamete formation, offspring would always show the trait of at least one of the parents. _________________________

101. 50The principles of probability can explain the numerical results of Mendel’s experiments. _________________________

103. 51The probability that a gamete produced by a pea plant heterozygous for stem height (Tt) will contain the recessive allele is 100%. _________________________

105. 52If Mendel had found that an F 2 cross of plants that were heterozygous for two traits had made offspring with two phenotypes, this finding would have supported the theory of independent assortment. _________________________

107. 53A trait in an unidentified plant is controlled by one gene that has two alleles. One allele is dominant over the other. According to Mendel’s principles, one fourth of the offspring made from a cross between two heterozygous plants will show the recessive trait. _________________________

109. 54If two speckled chickens are mated, according to the principle of codominance, 25% of the offspring are expected to be speckled. _________________________

111. 55Coat color in rabbits is determined by a single gene that has multiple alleles. _________________________

113. 56If an organism has 16 chromosomes in each of its egg cells, the organism’s diploid number is 32. _________________________

115. 57If an organism is heterozygous for a particular gene, the two different alleles will be separated during anaphase II of meiosis, assuming that no crossing-over has occurred. _________________________

117. 58Mitosis results in two cells, whereas meiosis results in one cell. _________________________

119. 59If an organism has four linkage groups, it has eight chromosomes. _________________________

121. 60Genes in the same linkage group are usually inherited separately. _________________________

123. 61The plants that Gregor Mendel crossed to produce the F 1 generation made up the ____________________ generation.

125. 62Due to the process of segregation, alleles separate during the production of ____________________

127. 63An organism has 38 chromosomes in a body cell. After mitosis each cell has 38 chromosomes. After meiosis each gamete has ____________________ chromosomes.

129. 64What is the probability of flipping a coin and getting heads 5 times in a row?

131. 65In the Punnett square shown in Figure 11–1, the genotypes of the offspring are ____________________. Tt Tt TT T Tt TTTTt T= Tall t= Short Figure 11 – 1

133. 66The principle of independent assortment states that ____________________ for different traits can segregate independently during the formation of gametes.

135. 67If pea plants that are homozygous for round, yellow seeds (RRYY) were crossed with pea plants that are heterozygous for round, yellow seeds (RrYy), the expected phenotype(s) of the offspring would be _________________________.

137. 68____________________’s principles can be used to study heredity in dogs, cats and sheep.

139. 69The reddish-brown pigment that gives color to a fruit-fly’s eye is controlled by three genes, so a fruit fly’s eye color is a __________________.

141. 70Western white butterflies that hatch in springtime have more pigment in their wings than those that hatch in summer. The darker wings help the butterflies stay warmer by absorbing more ____________________ than the lighter-colored wings.

143. 71The characteristics of an organism are determined by two factors: ____________________.

145. 72In four o’clock plants, flower color is controlled by two alleles that show _________________________.

147. 73An organism’s gametes have ____________________ the number of chromosomes found in the organism’s body cells.

149. 74Crossing-over occurs during the stage of meiosis called ____________________.

151. 75The relative locations of each known gene can be shown on a ____________________ map.