U5 Concept 1 - Mendelian Genetics Review

The form of a gene that is always expressed if present is the form.

• A. recessive

• B. dominant

• C. homologous

• D. heterozygous

Which of Mendel's laws BEST explains why an organism with a heterozygous genotype will show a dominant phenotype?

• A. Law of Dominance

• B. Law of Segregation

• C. Law of Independent Assortment

• D. Chromosome Theory of Inheritance

Two parents have the genotype Gg for a genetic disorder caused by a recessive allele. What is the chance that any of their children will inherit the disorder?

• A. 25%

• B. 50%

• C. 75%

• D. 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

Which of Mendel's laws states that organisms inherit two copies of each gene and donate one copy to each of their offspring?

• A. Law of Dominance

• B. Law of Segregation

• C. Law of Independent Assortment

• D. Chromosome Theory of Inheritance

In pigs, the allele for a wavy, rough coat (R) is dominant to the allele for a soft, fine coat (r). A rough coat boar and a soft coat sow mate. They produce several litters, 50% are rough coat and 50% are smooth coat. What must be the genotypes of the parents to create this phenotypic ratio?

• A. Homozygous dominant and homozygous recessive

• B. Heterozygous and homozygous recessive

• C. Homozygous dominant and heterozygous

• D. Both heterozygous

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

If two parents with dominant phenotypes produce an offspring with a recessive phenotype, then probably

• A. one parent is homozygous recessive.

• B. only one parent is heterozygous.

• C. both parents are homozygous dominant.

• D. both parents are homozygous recessive.

• E. both parents are heterozygous.

Tags

NGSS.HS-LS3-2

Given a dihybrid cross for a plant, where P (purple) is dominant to p (white) and S (spherical seeds) is dominant to s (dented seeds), what is the predicted phenotypic ratios if two plants are mated that are both heterozygous for both traits?

• A. 1 purple, spherical: 1 purple, dented: 1 white, spherical: 1 white, dented

• B. 8 purple, spherical: 8 purple, dented: 0 white, spherical: 0 white, dented

• C. 9 purple, spherical: 3 purple, dented: 1 white, spherical: 3 white, dented

• D. 9 purple, spherical: 3 purple, dented: 3 white, spherical: 1 white, dented