A plant with orange-spotted flowers was grown in the greenhouse from a seed collected in the wild. The plant was self-pollinated and gave rise to the following progeny: 88 plants with orange-spotted flowers, 34 plants with yellow-spotted flowers, 32 plants with solid orange flowers, and 8 plants with solid yellow flowers.

a. (1 point) What can you conclude about the dominance relationships of the alleles responsible for flower color and pattern? How many genes are involved?

There are two genes involved, one for flower color and one for flower pattern. There are two alleles for the flower color gene, with the orange allele (Y) dominant to the yellow allele (y). There are two alleles for the flower pattern gene, with the spotted allele (R) dominant to the unspotted allele (r).

b. (1 point) What was the genotype of the original plant with orange-spotted flowers?

the original plant was heterozygous for both genes: YyRr

c. (3 points) On a separate sheet of paper, draw a diagram that illustrates what happened to these alleles during meiosis in the original plant. Clearly label:

(a) the meiotic divisions (i. e. meiosis I and meiosis II)

(b) the homologous chromosomes, sister chromatids, genes and alleles

(c) all the genetically different gametes that could form and how frequently each type should be observed.

A plant with orange-spotted flowers was grown in the greenhouse from a seed collected in the wild. The plant was self-pollinated and gave rise to the following progeny: 88 plants with orange-spotted flowers, 34 plants with yellow-spotted flowers, 32 plants with solid orange flowers, and 8 plants with solid yellow flowers.

a. (1 point) What can you conclude about the dominance relationships of the alleles responsible for flower color and pattern? How many genes are involved?

b. (1 point) What was the genotype of the original plant with orange-spotted flowers?

c. (3 points) On a separate sheet of paper, draw a diagram that illustrates what happened to these alleles during meiosis in the original plant.  Clearly label:

(i) the meiotic divisions (i.e. meiosis I and meiosis II)

(ii) the homologous chromosomes, sister chromatids, genes and alleles

(iii) all the genetically different gametes that could form and how frequently each type should be observed

Explanation:

The question seeks to examine basic knowledge of the foundations of genetics.

1a. There are two genes involved in the dominance relationships of the alleles responsible for flower color and pattern, one serves the purpose of flower color and one for flower pattern. There are two alleles for the flower color gene, with the orange allele (Y) dominant to the yellow allele (y). It should be noted that two alleles  are responsible for the flower pattern gene –  with the spotted allele (R) dominant to the unspotted allele (r).

b. The genotype of the original plant is characteristically heterozygous for both genes: YyRr

c. The figure below shows how i, ii and iii relates under the law of independent assortment.

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements