Chapter 13—Patterns of Inheritance Key
1. The phenotype of an organism can often be determined
2. The character that we see as flower color in a pea plant is the result of
3. The genotype of an organism is
4. Consider this genotype: AaEE. How many genes are represented here?
5. Consider this genotype: AaEE. How many alleles are represented here?
6. Mendel’s principle of dominance implies that
7. Recessive traits
8. An allele which is visible only when homozygous is said to be
9. A genotype containing two identical alleles for a given character is said to be
10. A true breeding tall pea plant is crossed with a true breeding dwarf pea plant. All of the F1 offspring are tall.
What is the genotype of the tall parent plant?
11. A true breeding tall pea plant is crossed with a true breeding dwarf pea plant. All of the F1 offspring are tall.
What is the genotype of the dwarf parent plant?
12. A true breeding tall pea plant is crossed with a true breeding dwarf pea plant. All of the F1 offspring are tall.
What is the genotype of the F1 plants?
13. A true breeding tall pea plant is crossed with a true breeding dwarf pea plant. All of the F1 offspring are tall.
In words, how would you describe the genotype of the F1 plants?
14. In garden peas, tall (T) is dominant to dwarf (t). What offspring ratio would you expect from crossing a tall
(Tt) plant with a dwarf (tt) plant?
15. In garden peas, tall (T) is dominant to dwarf (t). What are the chances of getting a dwarf plant from crossing
a tall (Tt) plant with a dwarf (tt) plant? You must show your Punnett square to get full credit.
16. In garden peas, inflated pods (I) is dominant to pinched pods (i). What are the chances of getting pods that
are inflated from crossing a homozygous dominant plant with a heterozygous plant? You must show your
Punnett square to get full credit.
17. A tall pea plant (TT) and a different tall pea plant (Tt) have the same
18. A test cross can be performed to reveal
19. Mendel’s principle of segregation implies that the two alleles of a gene in a diploid organism
20. Diploid cells have chromosomes in
21. Homologous pairs of chromosomes correspond in
22. Mendel’s principle of independent assortment states that
23. A dihybrid cross
24. A parent heterozygous for two traits will produce ____ types of gametes with respect to those traits.
25. Characteristics such as kernel color in wheat that exhibit a wide range of variation are generally controlled
by
26. If two genes are on non-homologous chromosomes, they
27. When two or more genes are located on the same chromosome (and thus do not assort independently), they
are said to be
28. A useful tool for showing all possible combinations of gametes from a particular parental cross is a
29. If 76 out of 104 offspring express the dominant trait in a particular cross, the parents were most likely to be
30. In garden peas, yellow seed is dominant to green seed, and round seed is dominant to wrinkled seed. What
ratio in the F1 offspring would be expected from crossing a homozygous round, yellow seeded plant with a
homozygous wrinkled, green seeded plant.
31. The work of Gregor Mendel revolutionized the field of biology and laid the foundation for understanding
inheritance.
32. Mendel’s work proved that inheritance of traits was due to a blending of genetic information.
33. Mendel studied garden peas.
34. Pea plants naturally cross-fertilize.
35. Mendel knew about chromosomes and genes.
36. Genes are inherited as parts of chromosomes.
37. A dominant allele masks the expression of a recessive allele.
38. A individual with a heterozygous genotype displays the recessive phenotype.
39. Genes located on different chromosomes are inherited independently.
40. Independent assortment refers to the separation of homologous chromosomes during meiosis.
41. Segregation refers to the separation of homologous chromosomes during meiosis.
42. Segregation refers to the separation of homologous chromosomes during mitosis.
43. The chromosome theory of inheritance states that in order for a character to be inherited, there must be a
single gene for that trait present on a chromosome.
44. Crossing over greatly increases the new combinations of genes in gametes.
45. Independent assortment contributes to genetic variation.
46. All inheritance can be explained by dominant and recessive genes.
47. A heterozygous individual can have an intermediate phenotype when the character is the result of
incomplete dominance.
48. Incomplete dominance proves that inheritance is a blending phenomenon.
49. Some characters are the result of several interacting genes.
50. In order for a phenotype to be effected by the environment, the character must be polygenic.
51. ____________________ is the study of heredity.
52. Chromosomes that are the size, shape, and arrangement of genes are ____________________
chromosomes.
53. When only one allele is expressed in the heterozygous condition, its phenotype is ____________________.
54. A diploid organism having different alleles for the same gene is said to be ____________________.
55. The alternative forms of a gene that occupy the same locus on homologous chromosomes are
____________________.
56. A(n) ____________________ cross is one in which only one trait is studied.
57. The specific site on a chromosome occupied by a gene is called a(n) ____________________.
58. Groups of genes on the same ____________________ tend to be inherited together.
59. This genotype “Hh” is described as ____________________.
60. Homozygous is an example of a(n) ____________________.
61. A diagram used to predict the outcome of a genetic cross is a(n) ____________________.
62. You would perform a(n) ____________________ if you wanted to determine the genotype of an individual
with a dominant phenotype.
63. Segregation takes place during the cell division known as ____________________.
64. Independent assortment takes place during ____________________ of meiosis.
65. ____________________ leads to the different combinations of chromosomes (and alleles) that can are
present in the gametes as a result from meiosis.
66. Genetic maps can be deduced by studying ____________________ genes.
67. The occurrence of ____________________ can explain the failure of linked genes to be inherited together.
68. When the phenotype of a heterozygote is intermediate between those of its two parents, the alleles show
____________________.
69. Continuous variations in the phenotypes of offspring are seen with ____________________ inheritance.
70. The ____________________ in which an individual lives can affect an organism’s phenotype.
71. What is a test cross and what is its purpose?
72. Explain how an understanding of linkage has allowed scientists to produce genetic maps.
73. Discuss two features of sexual reproduction that contribute to genetic variation in the offspring.
74. You open a packet of corn seeds and divide the seeds into two piles. One pile of seeds is planted in a pot of
soil and placed on a sunny windowsill. The other pile of seeds is planted in the exact same way, but the pot is
placed in a dark cabinet. After 4 days, you place the pots next to each other and compare how the plants look
(their phenotypes). All of the plants in the sun have long, green leaves. All of the plants in the dark are yellow,
their leaves are not visible, and their stems are tall and spindly (these plants are etiolated). Based on your
understanding of inheritance, what is the most logical explanation for these phenotypic differences?