Heredity Exam Spring 2023

What law BEST explains why an organism with ‘Tt’ will show only the dominant phenotype?

• Law of Independent Assortment

• Law of Filial Generations

• Law of Dominance

• Law of Segregation

Two heterozygous purple-flowering pea plants are crossed. If purple is dominant over white, what are the expected phenotypic results?

• 25% purple, 75% white.

• 100% purple.

• 75% purple, 25% white.

• 50% purple, 50% white.

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

• zygote

• heterozygous

• recessive

• dominant

According to the Punnett square below: B represents the dominant gene for blue feathers and b represents the recessive gene for red feathers. A homozygous dominant bird and a homozygous recessive bird mate. What percent chance does the offspring have for red feathers?

• 0%

• 50%

• 100%

• 75%

Which Mendelian law of inheritance states that organisms inherit two copies of each gene and donate one copy to each of their offspring?

• law of segregation

• law of genetic linkage

• law of inheritance

• law of independent assortment

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?

• 100%

• 75%

• 50%

• 25%

If an organism inherits one dominant allele and one recessive allele for eye color, its genotype would be:

• homozygous

• homologous

• haploid

• heterozygous

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?

• Rr × rr

• RR × rr

• RR × Rr

• Rr × Rr

Imagine two heterozygous parents.  Each has a dominant allele A for brown eyes and a recessive allele for blue eyes.  What would the genotypic ratio of the offspring be?

• 100% Aa

• 50% AA  50% Aa

• 25% AA 50% Aa 25% aa

• 50% Aa 50% aa

Match the description of the phenotypes expressed with the corresponding inheritance pattern.

A cross between a white horse and a chestnut (dark brown) horse produces all light brown horses.

• Polygenic inheritance

• Sex-Linked

• Incomplete dominance

• Codominant