Genetics Probability

A dihybrid cross is created from plants that are heterozygous for both round seeds and yellow seed color. What is the ratio of offspring that have round seeds and yellow seed color?

• 1:16

• 3:16

• 9:16

• 16:16

Tags

NGSS.HS-LS3-2

NGSS.HS-LS4-3

The Punnett square predicts the ratio of genotypes in the offspring, based on the genotypes of the parents. The Punnett square below examines the chance of offspring having freckles, which is a dominant trait.

Based on the Punnett square, what is the probability that the offspring will have freckles?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Which term describes an organism that has identical alleles for a trait?

• homozygous

• heterozygous

• dominant

• recessive

The offspring of a particular cross are 100 percent heterozygous for the trait of plant height. What were the most likely genotypes of the parents?

• Tt x tt

• Tt x Tt

• tt x tt

• TT x tt

Tags

NGSS.HS-LS3-2

Mendel crossed two plants that were heterozygous for the trait of flower color. Which genotypes could he have used to represent the cross?

• PP x PP

• Pp x Pp

• pp x pp

• Pp x PP

Tags

NGSS.HS-LS3-2

In pea plants, tallness (T) is dominant to shortness (t). What are the predicted percentages of the genotypes of the offspring if a homozygous short plant is crossed with a heterozygous tall plant?

• 25 percent Tt, 75 percent tt

• 25 percent tall, 75 percent short

• 50 percent Tt, 50 percent tt

• 50 percent tall, 50 percent short

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The Punnett square predicts the ratio of genotypes in the offspring, based on the genotypes of the parents. In this cross, tallness (H) is dominant to shortness (h).

Based on the Punnett square, what is the phenotype of the offspring?

• Hh

• HH

• tall

• short

In a monohybrid cross between two heterozygous individuals (Aa), what is the probability of obtaining a homozygous recessive offspring?

• A) 0%

• B) 25%

• C) 50%

• D) 75%

Tags

NGSS.HS-LS3-1

If a plant with genotype AaBb is crossed with a plant with genotype aabb, what is the probability of obtaining an offspring with genotype aabb?

• A) 1/16

• B) 1/8

• C) 1/4

• D) 1/2

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

In a dihybrid cross, what is the probability of obtaining an offspring with a phenotype that is recessive for both traits?

• A) 1/16

• B) 3/16

• C) 9/16

• D) 1/4

Tags

NGSS.HS-LS4-3