Genetics Practice

Identical dominant alleles are

• hybrid

• homozygous dominant

• heterozygous recessive

• homozygous recessive

Homozygous is when...

• the alleles are the same
• the alleles are different
• the alleles are absent
• the alleles are present

Heterozygous is when...

• the alleles are the same
• the alleles are different
• the alleles are absent
• the alleles are present

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

Which of the following is a phenotype?

• Aa
• black hair
• heterozygous genes
• mutated DNA

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What is a dominant allele?

• A trait that is always shown (capital letter)
• A trait that can be hidden (lower case letter)
• Alleles that are the same
• Alleles that are different

Tags

NGSS.HS-LS3-1

In plants, tall (T) is dominant to short (t). Perform the following cross: Tt x Tt. What is the probability of producing a short plant?

• 0%
• 25%
• 50%
• 75%

Tags

NGSS.HS-LS3-3

In a flowering plant species, red flower color (R) is dominant over white flower color (r). What is the genotype of any red-flowering plant resulting from this species?

• rr
• R
• RR
• RR or Rr

Tags

NGSS.HS-LS3-1

What ratio of the offspring from the cross shown will be homozygous recessive for the  trait of tallness? 

• 0 in 4
• 1 in 4
• 2 in 4
• 4 in 4

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

A homozygous dominant brown mouse (BB) is crossed with a heterozygous brown mouse (tan is the recessive color). List the offspring genotype and phenotype.

• 50% homozygous dominant; 50% heterozygous and 100% tan
• 25% homozygous dominant; 75% heterozygous; 100% brown
• 50% homozygous dominant; 50% heterozygous and 100% brown
• 75% homozygous dominant; 25% heterozygous and 100% tan

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2