Monohybrid Crosses

Chickens have different types of feathers. Frizzled feathers curl towards a chicken's head. Assume that feather type is determined by a single gene and that the allele for frizzled feathers is dominant over the allele for straight feathers. In a cross between two chickens with straight feathers, what percentage of the offspring can be expected to have frizzled feathers?

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

In labrador retrievers the allele for a black coat color (B) is dominant over the allele for a brown coat color (b). If a brown labrador retriever is crossed with a heterozygous black labrador retriever, which of the following genotypic ratios can be expected?

• 0 BB: 2 Bb: 2 bb

• 1 BB: 2 Bb: 1 bb

• 2 BB: 0 Bb: 2 bb

• 2 BB: 1 Bb: 0 bb

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A homozygous dominant round seeded plant is crossed with a homozygous recessive wrinkled seeded plant. What are the genotypes of the parents?

• RR X rr
• Rr X rr
• rr X rr
• RR X Rr

Tags

NGSS.HS-LS3-1

which are the gametes for parent who are heterozygous

• Hh x hh

• HH x HH

• Hh x Hh

• hh x hh

if all offsprings are hybrid, what are the parents

• HH x Hh

• HH x hh

• hh x hh

• Hh x Hh

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

If a heterozygous tall pea plant is crossed with a short pea plant, what are the possible genotypes of the future offspring?

• 100% Tt
• 50% Tt, 50% tt
• 75%Tt, 25%tt
• 25%TT, 50%Tt, 25%tt

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

T - tall and t = short
In the punnett square below, what belongs in the missing square

• tt
• Tt
• Bb
• TT

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

AA and Aa always show up as

• dominant
• recessive

Tags

NGSS.HS-LS3-1

What are the possible genotypes for this cross?

• TT = 25% Tt= 50% tt=25%
• all tall
• TT= 75% tt = 25%
• Tt = 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

In cacti, long arms (A) are dominant to short arms (a).  Suppose 2 heterozygous cacti are crossed.  What percentage of their offspring are expected to have short arms?

• 0%
• 25%
• 75%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2