Monohybrids and Genetics

In cattle the allele for cloven hooves (H) is dominant over the allele for mule-foot hooves (h).

What is the probability of cloven hooves in the offspring of parents that are heterozygous for the trait?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-3

NGSS.HS-LS4-3

Albinism is an autosomal recessive condition. Which circle graph shows the genotype probability when an albino female mates with a male that is heterozygous for the albinism trait?

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Tomato plants usually have hairy stems. Hairless stems are present in tomato plants that are homozygous recessive for this trait. If the stem characteristics are determined by a single gene, what is the expected outcome of crossing two tomato plants that are heterozygous for hairy stems?

• 75% hairy stems: 25% hairless stems

• 100% hairy stems

• 100% hairless stems

• 50% hairy stems: 50% hairless stems

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

• 1 BB: 2 Bb: 1 bb

• 0 BB: 2 Bb: 2 bb

• 2 BB: 0 Bb: 2 bb

• 2 BB: 1 Bb: 0 bb

In horses, the gene for white hair ( W ) is dominant to the gene for non-white hair ( w ). A horse with genotype ( WW ) was crossed with a horse with genotype ( ww ).

What fraction of the offspring should be expected to have white hair?

• none

• one-half

• three-quarters

• all

Tags

NGSS.HS-LS3-1

In guinea pigs Black fur (B) is dominant to white(b), cross Bb x bb and determine genotypic ratio for offspring

• 2:2

• 0:2:2

• 1:2:1

• 2:2:0

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

In pea plants Tall stems (T)are dominant to short stems (t) cross a homozygous tall plant with a homozygous recessive plant, what is the phenotypic ratio

• 4:0

• 2:2:0

• 0:4

• 0:2:2

Tags

NGSS.HS-LS3-1

Which of the following is a phenotype?

• Aa
• red hair
• heterozygous
• DNA

If green is dominant over purple, then what is the genotype for this individual?

• Purple
• Green
• GG
• gg

Tags

NGSS.HS-LS3-1

Having two different alleles for a trait (example Hh):

• homozygous
• heterozygous
• dominant
• purebred