Exam 3: Extensions to Mendels Laws

If a trait is controlled by two codominant alleles of one gene, what phenotypic ratio is expected in the offspring of a mating of two heterozygotes?

Which ratio would indicate that a phenotype is controlled by multiple genes?

In primroses, the dominant allele of gene K is necessary to synthesize blue flower pigment. Blue pigment synthesis is inhibited by a dominant allele of gene D. In other words, plants with the genotype K- D- will not produce pigment (and their flowers will be white) because of the presence of the D allele. -If two dihybrid plants (Kk Dd)are crossed, what is the ratio of blue to white offspring in the progeny?

A particular flower can be purple, blue, red, or white.A pure-breeding red plant is crossed with a pure-breeding white one, and the F₁ are then crossed to produce an F₂ generation.Which of the following phenotypic ratios in the F₂ indicate that flower color in these plants is controlled by two genes?

Achondroplasia is a form of dwarfism in humans. It is caused by a mutant allele of the fibroblast growth factor receptor gene (FGFR) that produces an overactive protein. Having one copy of the mutant allele results in dwarfism. Two copies of the mutant allele results in death before birth. -If two people with achondroplasia have a child together, what is the probability that their child will also have achondroplasia?

Two pure-breeding phlox plants were crossed, one with dark-blue flowers and the other with pink flowers. The F1 generation all had dark-blue flowers. When the F1 were crossed with each other, the F2 generation consisted of 176 plants: 101 with dark-blue flowers, 33 with light-blue flowers, 30 with red flowers, and 10 with pink flowers -What progeny types would result from crossing a homozygous plant with light-blue flowers to a homozygous plant with red flowers?

The inheritance pattern of daisy flower color provides an example of what type of gene interaction?

If a gene for a trait is monomorphic in a population and two random individuals mate, what would be the most likely phenotypic ratio for that trait in the offspring?

Two alleles of gene C control hair color in horses: C¹ and C².Horses homozygous for allele C¹ are red, heterozygotes are yellow, and C² homozygotes are cream.What type of allele interaction is described?