Epistasis and Complementation Practice Problems

Epistasis is the interaction of ______ different genes.

Two pure-breeding strains of a plant, designated P1 and P2, produce flowers of the same color, which is purple. Each of these strains, when crossed with a pure-breeding strain X, produces F₁ progeny plants that have pink flowers. Determine the genotype of the progenies in the F₁ generation.

Two pure-breeding strains of a plant, designated P1 and P2, produce flowers of the same color, which is purple. Each of these strains, when crossed with a pure-breeding strain X, produces F₁ progeny plants that have pink flowers. When pure-breeding P1 and P2 are crossed, the F₁ progeny plants have pink flowers and self-fertilization of the F₁ progeny resulted in 9/16 plants with pink flowers and 7/16 plants with purple flowers. Determine the genotype of the parents of F₁ progeny.

Two pure-breeding strains of a plant, designated P1 and P2, produce flowers of the same color, which is purple. Each of these strains, when crossed with a pure-breeding strain X, produces F₁ progeny plants that have pink flowers. When pure-breeding P1 and P2 are crossed, the F₁ progeny plants have purple flowers and self-fertilization of the F₁ progeny resulted in 9/16 plants with pink flowers and 7/16 plants with purple flowers. Determine the number of genes in which variable alleles segregate

What effects does open chromatin have on gene transcription?

The phenomenon of epistasis occurs when the expression of one gene masks the expression of another. Which of the following statements best describes epistasis?

What is the phenotypic ratio of a dominant epistatic interaction?

The gene for the ABO blood group is found on chromosome _____, whereas the gene for the Bombay blood group is located on chromosome _____.

A type of gene interaction during which some recessive alleles at one locus inhibit the expression of both dominant and recessive alleles at another locus is referred to as:

Which of the following is an example of epistasis?

A couple's blood group genotype is IᴬIᴮHH and IᴬIᴮHH. What genotypic and phenotypic ratios may be expected in the offspring?

The shape of summer squash is classified as either long, spherical, or disk-shaped. Disk-shaped fruits are produced when dominant alleles are present at two gene loci, A and B. Spherical-shaped fruits are produced when a dominant allele is present at either the A or B gene loci. Long-shaped fruits are produced when the plant is homozygous recessive for both genes A and B. When a plant that produces spherical-shaped fruits is crossed with a plant that produces long-shaped fruits, the phenotypic proportion of the progeny obtained is as follows: 1/2 spherical fruit and 1/2 long fruit. Based on the segregation data, determine the genotype of the parents.

The shape of summer squash is classified as either long, spherical, or disk-shaped. Disk-shaped fruits are produced when dominant alleles are present at two gene loci, A and B. Spherical-shaped fruits are produced when a dominant allele is present at either the A or B gene loci. Long-shaped fruits are produced when the plant is homozygous recessive for both genes A and B. Two pure breeding plants that produce spherical-shaped fruits are crossed, and all the resultant F₁ progeny plants produce disk-shaped fruits. If the F₁ progeny was self-fertilized, determine the phenotypic ratio of the F₂ progeny.

The shape of summer squash is classified as either long, spherical, or disk-shaped. Disk-shaped fruits are produced when dominant alleles are present at two gene loci, A and B. Spherical-shaped fruits are produced when a dominant allele is present at either the A or B gene loci. Long-shaped fruits are produced when the plant is homozygous recessive for both genes A and B. Identify the type of gene interaction.

he shape of summer squash is classified as either long, spherical, or disk-shaped. Disk-shaped fruits are produced when dominant alleles are present at two gene loci, A and B. Spherical-shaped fruits are produced when a dominant allele is present at either the A or B gene loci. Long-shaped fruits are produced when the plant is homozygous recessive for both genes A and B. Two pure breeding plants that produce spherical-shaped fruits are crossed, and all the resultant F₁ progeny plants produce disk-shaped fruits. Determine the genotypes of the parental plants.

The flower color in a plant is produced by the blending of pigments from two biosynthetic pathways involving three genes, which produce three enzymes that catalyze the steps involved in the pathways of pigment production. Flower colors produced by mixing pigments are yellow (Red + green) and purple (pink + blue). Pink, red, blue, and green flowers result from the production of single colored pigments, while white flowers result from the absence of pigment production. [Note: An uppercase letter indicates a dominant allele producing full enzymatic activity, and a lowercase letter indicates a recessive allele producing no functional enzyme]

A cross was done between pure-breeding plants that produced purple flowers with the one producing white flowers. If the F₁ progeny was self-fertilized, determine the phenotypic ratio of the F₂ progeny.

The flower color in a plant is produced by the blending of pigments from two biosynthetic pathways involving three genes, which produce three enzymes that catalyze the steps involved in the pathways of pigment production. Flower colors produced by mixing pigments are yellow (Red + green) and purple (pink + blue). Pink, red, blue, and green flowers result from the production of single colored pigments, while white flowers result from the absence of pigment production. [Note: An uppercase letter indicates a dominant allele producing full enzymatic activity, and a lowercase letter indicates a recessive allele producing no functional enzyme]

Determine the genotype of pure-breeding plants that produce red flowers.

The flower color in a plant is produced by the blending of pigments from two biosynthetic pathways involving three genes, which produce three enzymes that catalyze the steps involved in the pathways of pigment production. Flower colors produced by mixing pigments are yellow (Red + green) and purple (pink + blue). Pink, red, blue, and green flowers result from the production of single colored pigments, while white flowers result from the absence of pigment production. [Note: An uppercase letter indicates a dominant allele producing full enzymatic activity, and a lowercase letter indicates a recessive allele producing no functional enzyme]

Determine the genotype of pure-breeding plants that produce yellow flowers.

A dominant allele of a gene creates a product that results in blue pigment, and a dominant allele of another gene acts on this product to produce green pigment. The presence of a recessive allele in homozygous condition for the gene producing blue pigment masks the phenotypic expression of the second gene producing green pigment. What is the possible molecular explanation for this genetic system?

A cross was done between two true-breeding genotypes AABB and aabb and the F₁ progeny thus obtained was self-fertilized. The F₂ progeny has a phenotypic ratio of 13:3. Which of the following statements about this cross is correct?

A cross was done between two true-breeding genotypes AABB and aabb and the F₁ progeny thus obtained was self-fertilized. The F₂ progeny has a phenotypic ratio of 15:1. Which of the following statements about this cross is correct?

Two strains of a plant, designated P1 and P2, produce flowers of the same color, which is purple. Each of these strain is crossed with a pure-breeding strain A, which produce pink flowers. The F₁ progeny plants of each cross have pink flowers. Self-fertilization of the F1 progeny of each cross resulted in 1/4 plants with purple flowers and 3/4 plants with pink flowers. In how many genes do variable alleles segregate in the two crosses?

In which of the following epistatic interaction both genes are required for the correct phenotype?

What is the phenotypic ratio of a heterozygous cross in a complementary gene interaction?

What is the phenotypic ratio of a heterozygous cross in recessive epistasis?

In parakeets, two genes, B and Y, contribute to two different pigment-producing biosynthetic pathways that produce either blue or yellow pigment. The wild-type parakeets have feathers that are green with a mixture of blue and yellow. They are also found to have blue feathers (due to the absence of yellow pigment), yellow feathers (due to the lack of blue pigment), and white feathers (the absence of both pigments). Determine the genotype of the F1 progeny when a pure-breeding blue parakeet is mated to a pure-breeding yellow parakeet.

In parakeets, two genes, B and Y, contribute to two different pigment-producing biosynthetic pathways that produce either blue or yellow pigment. The wild-type parakeets have feathers that are green with a mixture of blue and yellow. They are also found to have blue feathers (due to the absence of yellow pigment), yellow feathers (due to the lack of blue pigment), and white feathers (the absence of both pigments). Using this information, determine the genotype of pure-breeding yellow parakeets.

In parakeets, two genes, B and Y, contribute to two different pigment-producing biosynthetic pathways that produce either blue or yellow pigment. The wild-type parakeets have feathers that are green with a mixture of blue and yellow. They are also found to have blue feathers (due to the absence of yellow pigment), yellow feathers (due to the lack of blue pigment), and white feathers (the absence of both pigments). Using this information, determine the genotype of pure-breeding blue parakeets.

When one gene's expression is altered by the expression of one or more other genes, this is known as _______.