| Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. |
| 1. | Mendel discovered predictable patterns in the inheritance of traits. _________________________
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| 2. | Garden peas are difficult to grow because they mature slowly. _________________________
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| 3. | When Mendel cross-pollinated two varieties from the P generation that exhibited contrasting traits, he called the offspring the second filial, or F2, generation. _________________________
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| 4. | The contrasting forms of each character studied by Mendel appeared in a 3:1 ratio in the F2 generation. _________________________
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| 5. | A dominant allele masks the effect of a recessive allele. _________________________
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| 6. | The allele for a recessive trait is usually represented by a capital letter. _________________________
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| 7. | Heterozygous individuals have two of the same alleles for a particular gene. _________________________
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| 8. | The inheritance of sex-linked traits can be studied by making a pedigree of several generations of a family. _________________________
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| 9. | Refer to the illustration above. The father listed in the pedigree is most likely heterozygous for the trait. _________________________
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| 10. | Refer to the illustration above. Child #3 probably has the dominant phenotype. _________________________
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| 11. | Albinism is caused by a recessive allele. _________________________
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| 12. | The phenotype that results from an inherited pair of alleles depends on the instructions in the genes only. _________________________
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| 13. | Traits for different characters that are usually inherited together are said to be combined. _________________________
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| Multiple Choice
Identify the choice that best completes the statement or answers the question. |
| 14. | The passing of traits from parents to offspring is called a. | genetics. | c. | development. | b. | heredity. | d. | maturation. |
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| 15. | The difference between Mendel’s experiments in the area of heredity and those done by earlier researchers was that a. | earlier researchers did not have microscopes. | b. | earlier researchers used detailed and numerical procedures. | c. | Mendel expressed the results of his experiments in terms of numbers. | d. | Mendel used pea plants with both purple and white flowers. |
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| 16. | a. | meiosis. | c. | genetics. | b. | crossing-over. | d. | pollination. |
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| 17. | The “father” of genetics was a. | A. Knight. | c. | Gregor Mendel. | b. | Hans Krebs. | d. | Charles Darwin. |
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| 18. | Garden peas are good subjects for studying heredity because they a. | are difficult to grow. | c. | produce few offspring. | b. | mature quickly. | d. | have few traits. |
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| 19. | Mendel obtained his P generation by allowing the plants to a. | self-pollinate. | c. | assort independently. | b. | cross-pollinate. | d. | segregate. |
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| 20. | Step 1 of Mendel’s garden pea experiment, allowing each variety of garden pea to self-pollinate for several generations, produced the a. | F1 generation. | c. | P generation. | b. | F2 generation. | d. | P1 generation. |
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| 21. | F2 : F1 :: a. | P : F1 | c. | F1 : P | b. | F1 : F2 | d. | P : F2 |
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| 22. | An allele that is always expressed whenever it is present is called a. | dominant. | c. | recessive. | b. | phenotypic. | d. | superior. |
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| 23. | The discovery of chromosomes provided a link between the first law of heredity that stemmed from Mendel’s work and a. | pollination. | c. | mitosis. | b. | inheritance. | d. | meiosis. |
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| 24. | The law of segregation states that a. | alleles of a gene separate from each other during meiosis. | b. | different alleles of a gene can never be found in the same organism. | c. | each gene of an organism ends up in a different gamete. | d. | each gene is found on a different molecule of DNA. |
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| 25. | Mendel’s law of segregation states that a. | pairs of alleles are dependent on one another when separation occurs during gamete formation. | b. | pairs of alleles separate independently of one another after gamete formation. | c. | each pair of alleles remains together when gametes are formed. | d. | the two alleles for a trait segregate independently when gametes are formed. |
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| 26. | The phenotype of an organism a. | is used to represent its genetic composition. | b. | is the physical appearance of a trait. | c. | occurs only in dominant individuals. | d. | cannot be seen. |
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| 27. | If an individual possesses two recessive alleles for the same trait, the individual is said to be a. | homozygous for the trait. | c. | heterozygous for the trait. | b. | haploid for the trait. | d. | mutated. |
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| 28. | When an individual heterozygous for a trait is crossed with an individual homozygous recessive for the trait, the offspring produced will a. | all have the same genotype. | b. | show two different phenotypes. | c. | show three different phenotypes. | d. | all have the same phenotype. |
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| 29. | Tallness (T) is dominant to shortness (t) in pea plants. Which of the following represents a genotype of a pea plant that is heterozygous for tallness? |
| 30. | homozygous : heterozygous :: a. | heterozygous : Bb | c. | probability : chance | b. | gg : Gg | d. | factor : gene |
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| 31. | Mendel’s finding that the inheritance of one trait had no effect on the inheritance of another became known as the a. | law of dominance. | b. | law of universal inheritance. | c. | law of separate convenience. | d. | law of independent assortment. |
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| | In humans, having freckles (F) is dominant to not having freckles (f). The inheritance of these traits can be studied using a Punnett square similar to the one shown below. |
| 32. | Refer to the illustration above. The child represented in box 1 in the Punnett square would a. | be homozygous for freckles. | b. | have an extra freckles chromosome. | c. | be heterozygous for freckles. | d. | not have freckles. |
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| 33. | Refer to the illustration above. The parents shown in the Punnett square could have children with a phenotype ratio of a. | 1:2:1. | c. | 3:1. | b. | 4:0. | d. | 2:2. |
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| 34. | Refer to the illustration above. Which box in the Punnett square represents a child who does not have freckles? a. | box 1 | c. | box 3 | b. | box 2 | d. | box 4 |
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| 35. | Refer to the illustration above. The child in box 3 of the Punnett square has the genotype |
| | In rabbits, black fur (B) is dominant to brown fur (b). Consider the following cross between two rabbits. |
| 36. | Refer to the illustration above. The device shown, which is used to determine the probable outcome of genetic crosses, is called a a. | Mendelian box. | c. | genetic graph. | b. | Punnett square. | d. | phenotypic paradox. |
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| 37. | Refer to the illustration above. Both of the parents in the cross are a. | black. | c. | homozygous dominant. | b. | brown. | d. | homozygous recessive. |
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| 38. | Refer to the illustration above. The phenotype of the offspring indicated by box 3 would be a. | brown. | c. | a mixture of brown and black. | b. | black. | d. | white. |
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| 39. | Refer to the illustration above. The genotypic ratio of the F1 generation would be a. | 1:1. | c. | 1:3. | b. | 3:1. | d. | 1:2:1. |
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| 40. | What is the expected genotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross? |
| 41. | What is the expected genotypic ratio resulting from a heterozygous ´ heterozygous monohybrid cross? |
| 42. | What is the expected phenotypic ratio resulting from a homozygous dominant ´ heterozygous monohybrid cross? |
| 43. | The unknown genotype of an individual with a dominant phenotype can be determined using a a. | ratio. | c. | probability formula. | b. | dihybrid cross. | d. | test cross. |
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| 44. | What is the probability that the offspring of a homozygous dominant individual and a homozygous recessive individual will exhibit the dominant phenotype? |
| 45. | Probability is calculated by dividing the number of one kind of possible outcome by the a. | number of other kinds of outcomes. | b. | total number of all possible outcomes. | c. | number of genes being considered. | d. | total number of offspring produced. |
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| 46. | If a characteristic is sex-linked, the gene for it is found on a. | a sex chromosome. | c. | a linked chromosome. | b. | an autosome. | d. | an allele. |
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| 47. | Since the allele for colorblindness is located on the X chromosome, colorblindness a. | cannot be inherited. | c. | is sex-linked. | b. | occurs only in adults. | d. | occurs only in females. |
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| 48. | A diagram in which several generations of a family and the occurrence of certain genetic characteristics are shown is called a a. | Punnett square. | c. | pedigree. | b. | monohybrid cross. | d. | family karyotype. |
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| 49. | In humans, eye color and height are controlled by a. | simple dominance. | c. | polygenic inheritance. | b. | multiple alleles. | d. | incomplete dominance. |
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| 50. | Which of the following traits is controlled by multiple alleles in humans? a. | eye color | c. | colorblindness | b. | blood type | d. | albinism |
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| 51. | What would be the blood type of a person who inherited an A allele from one parent and an O allele from the other? a. | type A | c. | type AB | b. | type B | d. | type O |
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| 52. | Which of the following is not an outcome of the environment modifying a phenotype? a. | the changing of the color of an animal’s fur as the temperature changes | b. | the increased intelligence of a person who attended school for many years | c. | the very short stature of a kind of tree that grows at a high altitude in comparison with the same kind of tree growing at a lower altitude | d. | the pink-flowered snapdragons that result from crosses between red-flowered and white-flowered snapdragon plants |
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| 53. | Genes that are close together on a single chromosome are considered to be a. | alleles. | c. | independent. | b. | homozygous. | d. | linked. |
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