Dihybrid cross

A male beetle has the genotype Ttbb. If this beetle mates with a female with genotype TTBb, what is the chance their offspring will have the genotype TtBb?

• 12.5%
• 25%
• 50%
• 75%

Tags

NGSS.HS-LS3-3

A vampire bat mom is homozygous dominant for red eyes (RR) and heterozygous for fluffy ears (Ff).
The vampire bat father is homozygous recessive for black eyes (rr) and has fluffy ears.
If some of the vampire bat babies have smooth ears, what percentage of babies will have the same eyes and ears as their mom?

• 25%
• 50%
• 75%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A speckled hen has black and white spots. The chicken mates with a black rooster with no white spots. If feather color is a co-dominant trait, which of the following are the most likely traits for their offspring?

• 21 chicks with black and white spots
• 9 chicks with black and white spots, 11 chicks solid black
• 30 chicks with black and white spots, 7 chicks all black
• 12 chicks all white, 14 chicks all black

What is the genotype for a pea plant heterozygous for round seeds (R), and homozygous recessive for green seeds (y)?

• Ry
• RRyy
• RrYy
• Rryy

Tags

NGSS.HS-LS3-2

Which of the following genotypes is heterozygous?

• Bb
• BB
• bb
• B

Which of the following genotypes is homozygous dominant?

• A
• Aa
• AA
• aa

Cross Two Homozygous plants
(RRYY x rryy)
R = round seeds, r  = wrinkled seeds Y = yellow seeds, y = green seeds
What percent will have Round and Yellow seeds? 

• 0%
• 25%
• 50%
• 100%

What fraction of offspring from the cross AaBB x Aabb will be heterozygous for both traits?

• 1/16
• 4/16
• 8/16
• 3/16

Tags

NGSS.HS-LS3-3

Aa, DD, bB, yy are all examples of

• genotypes
• phenotypes

Which of the following genotypes is homozygous dominant?

• A
• Aa
• AA
• aa