Punnett Squares and Probability

In cattle, the allele for a black-haired coat (B) is dominant over the allele for a red-haired coat (b). What combination of parental alleles will produce all purebred, black-haired offspring?

• bb x bb

• Bb x Bb

• BB x bb

• BB x BB

Tags

NGSS.HS-LS3-2

In pea plants, the trait for green seed pods (G) is dominant over the trait for yellow seed pods (g). Which cross will produce the maximum number of offspring with green seed pods?

• GG × gg

• Gg × gg

• Gg × Gg

• gg × gg

Short tails (T) are dominant to long tails (t). What is the probability of a long-tailed mouse in the cross Tt x tt?

• 25%

• 50%

• 75%

• 100%

In pea plants, purple flowers are dominant over white flowers. A plant that is homozygous for purple flowers is crossed with a plant homozygous for white flowers.

If the offspring from this cross are allowed to self-pollinate (cross with themselves), what will be the ratio of purple to white flowers in the second generation?

• 2:2

• 4:0

• 1:3

• 3:1

The Punnett square shows a cross between a heterozygous tall (Tt) and a homozygous short (tt) pea plant.

What are the correct genotypic and phenotypic ratios of the resulting offspring?

• genotype: 1:1; phenotype: 1:1

• genotype: 2:1; phenotype: 1:2

• genotype: 3:1; phenotype: 3:3

• genotype: 4:1; phenotype: 1:4

Examine the Punnett square showing the inheritance of flower color in plants.

If (R) represents the dominant color red, and (r) represents the recessive color white, what is the possibility that the two plants will have white offspring?

• 0%

• 50%

• 75%

• 100%

Tags

NGSS.MS-LS3-2

Examine the Punnett square that shows the probable offspring of a cross between two watermelons where G represents solid green and g represents striped watermelons.

What would be the genotypes for the parents?

• GG x GG

• gg x gg

• GG x Gg

• Gg x Gg

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The Punnett square shows four combinations of alleles for black fur (B) and white fur (b).

Which genotype should replace the question mark?

• BB

• Bb

• bb

• b

Tags

NGSS.MS-LS3-2

In chickens, the trait for yellow legs (Y) is dominant over the trait for white legs (y). A breeder wants to cross his chickens to have offspring with an equal ratio of chicks with yellow and white legs. Which Punnett square best represents the outcome that the breeder desires?

• 
• 
• 
• 

In rabbits, fur can be brown (B) or white (b). Cross a brown rabbit (Bb) and a white rabbit. What can be predicted about the offspring?

• Half of the offspring will have brown fur, and the other half will have white fur.

• None of the offspring will have exactly the same genotype as either of the parents.

• All offspring will have a mixture of brown and white fur.

• All offspring will be hybrids for the alleles that control fur color.