Class VI - Gene interactions

A 15:1 F2 phenotypic ratio of a dihybrid cross is typical of:

• redundancy

• overdominance

• modifiers

• epistasis

Same phenotype caused by mutations in different genes

• modifiers

• X-linked

• complementation

• redundancy

Here are the results of a complementation test. How many genes are mutated across these 7 strains strains?

• 2

• 1

• 4

• 3

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A phenomenon where two affected, recessive parents have unaffected offspring

• complementation

• lethal alleles

• pleiotropy

• X-linked

Tags

NGSS.HS-LS3-1

A mutation in a single gene impacts flower color and plant height. This is an example of:

• epistasis

• modifiers

• pleiotropy

• overdominance

You expect a 3:1 ratio of phenotypes from a F2 monohybrid cross. Instead you observe 2:1. What might be happening?

• allele is lethal in homozygotes

• there are modifiers

• there is redundancy in the genome

• the gene has pleiotropic functions

Tags

NGSS.HS-LS3-2

You cross two brown mice together and get a 9:3:4 phenotypic ratio of brown:black:white mice. What is happening????

• redundancy

• pleiotropy

• lethal alleles

• modifiers

Deep in the heart of a top secret McDonald's research facility, you breed two purple Grimaces together and a get 9:7 ratio of purple to white Grimaces. What could explain this outcome?

• Overdominance

• Epistasis

• Modifiers

• Incomplete penetrance

Human males have 1. ___ copies of the X chromosome, making genes on this chromosome 2. ___

• 1. 2

  2. 2. Homozygous

• 1. 1. 1

  2. 2. Homozygous

• 1. 1. 1

  2. 2. Hemizygous

• 1. 1. 2

  2. 2. Hemizygous