28. Cell division in which the sister chromatids fail to separate properly is called
a. multiple alleles.
b. nondisjunction.
c. nonsynapsis.
d. trisomy.
29. When a person’s cells have an extra copy of chromosome 21, it usually results in
a. Down syndrome.
b. Turner’s syndrome.
c. Tay-Sachs disease.
d. Klinefelter’s syndrome.
30. An individual with the chomosomal genotype XYY would be
a. a nearly normal female.
b. a female with Turner’s syndrome.
c. a nearly normal male.
d. a male with Klinefelter’s syndrome.
33. The base-pairing rule for binding purines and pyrimidines in the DNA molecule is
a. C-U and A-G
b. A-G and C-T
c. A-T and C-G
d. C-A and G-T
38. In a test cross, if one parent’s genotype is homozygous dominant,
a. all of the offspring will have the dominant phenotype.
b. 3/4 of the offspring will have the dominant phenotype.
c. 1/2 of the offspring will have the dominant phenotype.
d. 1/4 of the offspring will have the dominant phenotype.
a. multiple alleles.
b. nondisjunction.
c. nonsynapsis.
d. trisomy.
29. When a person’s cells have an extra copy of chromosome 21, it usually results in
a. Down syndrome.
b. Turner’s syndrome.
c. Tay-Sachs disease.
d. Klinefelter’s syndrome.
30. An individual with the chomosomal genotype XYY would be
a. a nearly normal female.
b. a female with Turner’s syndrome.
c. a nearly normal male.
d. a male with Klinefelter’s syndrome.
33. The base-pairing rule for binding purines and pyrimidines in the DNA molecule is
a. C-U and A-G
b. A-G and C-T
c. A-T and C-G
d. C-A and G-T
38. In a test cross, if one parent’s genotype is homozygous dominant,
a. all of the offspring will have the dominant phenotype.
b. 3/4 of the offspring will have the dominant phenotype.
c. 1/2 of the offspring will have the dominant phenotype.
d. 1/4 of the offspring will have the dominant phenotype.