Genetics Test Questions

Genetics Practice Test

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____ 1. Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that
a.|peas show easily observed variations in a number of characters, such as pea shape and flower color.|
b.|it is possible to control matings between different pea plants.|
c.|it is possible to obtain large numbers of progeny from any given cross.|
d.|peas have an unusually long generation time.|
e.|many of the observable characters that vary in pea plants are controlled by single genes.|

____ 2. What is the difference between a monohybrid cross and a dihybrid cross?
a.|A monohybrid cross involves a single parent, whereas a dihybrid cross involves two parents.|
b.|A monohybrid cross produces a single progeny, whereas a dihybrid cross produces two progeny.|
c.|A dihybrid cross involves organisms that are heterozygous for two characters and a monohybrid only one.|
d.|A monohybrid cross is performed for one generation, whereas a dihybrid cross is performed for two generations.|
e.|A monohybrid cross results in a 9:3:3:1 ratio whereas a dihybrid cross gives a 3:1 ratio.|

____ 3. A cross between homozygous purple-flowered and homozygous white-flowered pea plants results in offspring with purple flowers. This demonstrates
a.|the blending model of genetics.|
b.|true-breeding.|
c.|dominance.|
d.|a dihybrid cross.|
e.|the mistakes made by Mendel.|

____ 4. The offspring of Mendel's classic pea cross always looked like one of the two parental varieties because
a.|one phenotype was completely dominant over another.|
b.|each allele affected phenotypic expression.|
c.|the traits blended together during fertilization.|
d.|no genes interacted to produce the parental phenotype.|
e.|different genes interacted to produce the parental phenotype.|

____ 5. What was the most significant