Genetics and Heredity Review

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

• recessive

• dominant

• zygote

• heterozygous

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

phenotypic results?

• 100% purple.

• B. 75% purple, 25% white.

• 50% purple, 50% white.

• 25% purple, 75% white.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-3

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

• Law of Dominance

• Law of Segregation

• Law of Independent Assortment

• Law of Filial Generations

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

• haploid

• homozygous

• heterozygous

• homologous

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?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

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 genetic linkage

• law of segregation

• law of independent assortment

• law 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?

• RR × rr

• Rr × rr

• RR × Rr

• Rr × Rr

Tags

NGSS.HS-LS3-1

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

Tags

NGSS.HS-LS3-2

TT is

• heterozygous

• homozygous

Tt is

• heterozygous

• homozygous