SCI9 - HEREDITY

Which of the following is true of dominant and recessive alleles?

• Recessive traits are expressed only if the dominant allele is absent

• An individual can only have either dominant or recessive alleles

• When both alleles are present, the resulting phenotype is the "blend" of the two traits

• Phenotype is only determined by recessive alleles

A male bird is homozygous recessive for both wacky wings (w) and flashy feathers (f). He is crossed with a female who is homozygous dominant (normal wings and normal feathers) for both traits. What are the genotypes of these birds? (male; female).

• wwFF; WwFf

• wwff; WWFF

• WwFf; wwff

• WWFF; wwff

A dog breeder crosses two dogs that are heterozygous for brown coats. Some of the puppies have brown coats, and some have black coats. Assuming that coat color is controlled by a single gene, which of the following statements is most likely true?

• The allele for brown coat has mutated into an allele for black coats

• The allele for brown coat is recessive to the allele for black coat.

• The allele for brown coat is dominant to the allele of black coat.

• The alleles for brown and black coats are on different chromosomes.

In humans, L = lactase persistence (ability to break down lactose); l = lactose intolerance (inability to break down lactose). Which is the correct genotype and phenotype combinations is correctly labeled?

• Ll = homozygous dominant, lactase persistence

• LL - homozygous recessive; lactose intolerance

• ll = homozygous recessive; lactose intolerance

• Ll = heterozygous; lactose intolernace

When white-coated cattle (W) are mated with red-coated cattle (R), the offspring are roan (WR), meaning their coats contain both white and red hairs. This is an example of codominance.

A farmer breeds two roan cattle with one another.

What is the chance that their offspring will be roan?

• 0%

• 25%

• 50%

• 75%

In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s).

Which of the following pairs of terms are correctly matched?

• Ss - phenotype; smooth pod - genotype

• ss - genotype; constricted pod - phenotype

• ss - phenotype; constricted pod - genotype

• SS - genotype; constricted pod - phenotype

In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s).

Which of the following pairs of terms are correctly matched?

• Ss - phenotype; smooth pod - genotype

• ss - genotype; constricted pod - phenotype

• ss - phenotype; constricted pod - genotype

• SS - genotype; constricted pod - phenotype

In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s).

Which of the following pairs of terms are correctly matched?

• Ss - phenotype; smooth pod - genotype

• ss - genotype; constricted pod - phenotype

• ss - phenotype; constricted pod - genotype

• SS - genotype; constricted pod - phenotype

In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s).

Which of the following pairs of terms are correctly matched?

• Ss - phenotype; smooth pod - genotype

• ss - genotype; constricted pod - phenotype

• ss - phenotype; constricted pod - genotype

• SS - genotype; constricted pod - phenotype

In pea plants, the allele for smooth pods (S) is dominant over the allele for constricted pods (s).

Which of the following pairs of terms are correctly matched?

• Ss - phenotype; smooth pod - genotype

• ss - genotype; constricted pod - phenotype

• ss - phenotype; constricted pod - genotype

• SS - genotype; constricted pod - phenotype