Genetics-2

Pea plants can have green or yellow seeds. In a pea plant that is heterozygous for seed color, the allele for yellow seeds masks the effects of the allele of green seeds. Which of the following terms best describes the allele for yellow seeds?

• codominant
• recessive
• dominant
• sex-linked

In mussels, the allele for brown coloring (B) is dominant, and the allele for blue coloring(b) is recessive. For which parental genotypes are 100% of the offspring expected to be blue?

• BbxBb
• bbxbb
• BBxbb
• BBxBB

In guinea pigs, the alleles for black hair(B) is dominant to the allele for brown hair(b). Two black-haired guinea pigs are crossed. One of the pigs is homozygous for black hair and one is heterozygous. What percentage of their offspring are expected to have black hair?

• 25%
• 50%
• 75%
• 100%

In a flowering plant species, red flower cover is dominant over white flower color. What is the genotype of any red-flowering plant resulting from this species?

• red and white alleles present on one chromosme
• red and white alleles present on two chromosomes
• a red allele present on both chromosmes
• a red allele present on at least one of the two homologous chromosomes.

Which will most likely cause a gene to mutate?

• water
• radiation
• soil

What advantage do organisms that reproduce sexually have or organisms that reproduce asexually?

• Organisms that reproduce sexually can reproduce faster

• Organisms that reproduce sexually don't need a mate

• Organisms that reproduce sexually have a better chance of survival if the environment changes

• Organisms that reproduce sexually are exactly like their parents.

Unattached earlobes (E) is dominant. Attached earlobes (e) is recessive. A woman with the genotype (Ee) and a man with the genotype (ee) have a child. What is the probability that the child is heterozygous?

• 0%
• 25%
• 50%
• 75%

If the allele for gray fur (G) is dominant to the allele for white fur (g) in mice, What will be the ratio if you cross a heterozygous gray mouse with a white mouse?

• 3GG : 0Gg : 1gg
• 2GG : 1Gg : 1gg
• 1GG : 2Gg : 1gg
• 0GG : 2Gg : 2gg

In cocker spaniels the allele for a black coat color (B) is dominant over the allele for a brown coat color (b). If a brown cocker spaniel is crossed with a heterozygous black cocker spaniel, which of the following genotypic ratios can be expected?

• 0BB : 2Bb : 2bb
• 1BB : 2Bb : 1bb
• 2BB : 0Bb : 2bb
• 2BB : 1Bb : 0bb

What is being depicted in this picture?

• sexual reproduction
• anaphase I of meiosis
• crossing-over
• replication