Exam 13: Observing Patterns in Inherited Traits

MATCHING Classification.Answer the following questions using the group of answers below. a.4 b.6 c.8 d.12 e.24 -Animal species X is tetraploid (4n = 12).Following gene duplication and translocation, a given gene is found on each chromosome.How many alleles for this gene can be present in an individual of this species?

In sweet peas, genes C and P are necessary for colored flowers.In the absence of either (__ pp or cc __) or both (cc pp), the flowers are white.What will be the color of the offspring of the crosses listed below and in what proportions? (a) Cc Pp * cc pp (b) Cc Pp *Cc Pp (c) Cc PP * Cc pp (d) Cc pp * cc Pp

-Which offspring in the illustration above are homozygous recessive for both traits?

A cross of two Kerry horses always produces Kerry.A cross of a Kerry with a Dexter produces 1/2 and 1/2.Crosses of two Dexters produce two Dexters for every Kerry.Explain.

If black fur color is controlled by a dominant allele (B) and brown by its recessive allele (b), give the genotypes of the parents and offspring of a cross of a black male with a brown female that produces 1/2 black offspring and 1/2 brown offspring.

In a certain breed of chicken, an incomplete dominant gene controls color.The homozygous black, when crossed with the homozygous splashed-white, produces an intermediate gray color pattern referred to as blue.A second gene controls the shape of the comb.The dominant allele (R) produces rose, whereas the recessive allele (r) produces single.Give the F₁ and F₂ genotypic and phenotypic ratios of a cross between a pure-breeding black single and a pure-breeding splashed-white rose.

In which of the following does environment not play a role?

White fruit color in summer squash is influenced by a dominant allele W, whereas colored fruit must be ww.In the presence of ww, a dominant gene G results in yellow fruit, and if the individual had both recessive genes in the homozygous condition, it would be green.Give the F₂ phenotypic ratios resulting from a cross of a pure-breeding white of genotype WW GG with a green.

Which is easier to establish in a pure-breeding population, a dominant or a recessive gene?

The most accurate description of an organism with genotype AaBb is

In a certain variety of plants, a cross between a red-flowered plant and a white-flowered plant produced an all-red flower F₁.In the F₂ there were 140 red, 50 cream, and 65 white. (a) Offer an explanation for this F₂ ratio. (b) What ratio would be produced in a testcross of the F₁ hybrid? (c) What ratio would be produced if all the white F₂ plants were crossed among themselves?

Mendel's monohybrid experiment results led to his law of __________.

Pleiotropic genes

A __________ is a hybrid, with two nonidentical alleles (Aa).

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color.The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p).A tall purple crossed with a tall purple produces 3/4 tall purple and 1/4 tall white.What is the genotype of the parents?

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color.The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p).A tall plant with white flowers crossed with a dwarf plant with purple flowers produces all tall offspring with purple flowers.What is the genotype of the parents?

In radishes, two incompletely dominant genes control color and shape.Red and white radishes are homozygous, whereas the hybrid is purple.Long and round are homozygous and, if crossed, will produce an oval hybrid.Give the F₂ genotypic and phenotypic ratio produced by crossing pure-breed red long radishes with white round varieties.

In horses, black coat color is influenced by the dominant allele (B), and chestnut coat color is influenced by the recessive allele (b).Trotting gait is due to a dominant gene (T), pacing gait to the recessive allele (t).If a homozygous black trotter is crossed to a chestnut pacer, (a) what will be the appearance of the F₁ and F₂ generations? (b) which phenotype will be the most common? (c) which genotype will be the most common? (d) which of the potential offspring will be certain to breed true?

-A graph of phenotypic variation similar to the illustration above strongly suggests

-The illustration above shows the F₂ phenotypes from a monohybrid cross in snapdragons.What type of inheritance produces such an outcome?