Monohybrid Cross Practice

Can you curl your tongue up on the sides? Tongue-curling in humans is a dominant genetic trait. Suppose a man who is Tt for tongue-curling marries a woman who is also Tt for this trait. What are the possible genotypes of the offspring?

• TT, Tt, tt

• TT or tt

• Tt

• TT

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

Can you curl your tongue up on the sides? Tongue-curling in humans is a dominant genetic trait. Suppose a man who is Tt for tongue-curling marries a woman who is also Tt for this trait. What is the percent chance that their offspring will NOT be able to roll their tongue?

• 50%

• 100%

• 25%

• 0%

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

In dogs, there is a hereditary deafness caused by a recessive gene, “d.” A kennel owner has a male dog (Gilbert) that she wants to use for breeding purposes if possible. The dog can hear. What are the possible genotypes for Gilbert?

• DD or dd

• DD only

• Dd only

• DD or Dd

Tags

NGSS.HS-LS3-1

If the dog’s (Gilbert) genotype is Dd, the owner does not wish to use him for breeding so that the deafness gene will not be passed on. This can be tested by breeding the dog to a deaf female (dd). What are the chances that the offspring will be deaf if Gilbert is heterozygous?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

If the dog (Gilbert) is homozygous for having normal hearing, what are the chances the offspring will be deaf when mated with a deaf female?

• 0%

• 50%

• 25%

• 75%

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

In rabbits, black fur (B) is dominant over white fur. Show the cross of a heterozygous male with a homozygous white female. Complete a Punnett Square to support your answer, you will need it for number 7 too. What are the genotypic ratios of the offspring?

• 1 (BB): 2 (Bb) : 1 (bb)

• 0 (BB): 4 (Bb) : 0 (bb)

• 2 (Bb) : 2 ( bb)

• 3 (Bb) : 1 (bb)

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

Using the Punnett Square from #6. What is the percent chance that the offspring will be white?

• 75%

• 50%

• 25%

• 0%

Tags

NGSS.HS-LS3-3

Wrinkled seed (r) are recessive to smooth seeds. Show a wrinkled seed plant crossed with a heterozygous smooth seed plant. What is the chance that the offspring will be smooth and what will its genotype be?

• 50% RR

• 75% Rr

• 75% RR

• 50% Rr

Tags

NGSS.HS-LS3-3

Hornless (H) in cattle is dominant over horned (h). A pure bred hornless bull is mated with a pure bred horned cow. What will be the genotype and phenotype of the offspring using percent's? Make sure to make a punnett square as it will be needed to answer #10.

• 50% hornless (Hh) and 50% horned (hh)

• 100% hornless (Hh)

• 25% hornless (HH), 50% hornless (Hh), 25% horned (hh)

• 75% hornless (Hh), 25% horned (hh)

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1

Two of this offspring from #9 are mated. What would the phenotypic ratio be from this cross? Make a new punnett square using 2 of the offspring from #9. Remember hornless is dominant over having horns.

• 3 (hornless) : 1 (horned)

• 2 (hornless) : 2 (horned)

• 4 (hornless) : 0 (horned)

• 0 (hornless) : 4 (horned)

Tags

NGSS.HS-LS3-3

NGSS.HS-LS3-1