Sex Linked Trait Review

Which of the following genotypes shows a CARRIER for a trait?

• X^BX^b

• X^bX^b

• X^BX^B

• X^bY

Colorblindness is a recessive X-linked disorder.

Which genotype represents a male with normal vision?

• X^N Y^N

• Xⁿ Yⁿ

• X^N Y

• Xⁿ Y

Which of the following genotypes belongs in the red box in the Punnett square?

• X^BX^b
• X^bX^b
• X^bY
• X^BY

Different variations of a gene are called?

• Alleles
• DNA
• Chromosome
• Gene

Colorblindness is more common in males than in females because......

• fathers pass the allele for colorblindness to their sons only

• the allele for colorblindness is located on the Y chromosome

• the allele for colorblindness is recessive and located on the X chromosome

• males who are colorblind have two copies of the allele for colorblindness

What would the genotype be of a colorblind male?

• X^NY

• X^NYⁿ

• XⁿY

• XⁿYⁿ

How many recessive genes does a carrier female have for colorblindness?

• 1

• 2

• 0

• 3

Colorblindness is a sex-linked recessive trait. A colorblind woman marries a male with normal color vision. What is the percent chance of them having a color blind son?

• 0%

• 25%

• 50%

• 75%

The woman who is colorblind marries a man with normal vision. What is the probability that their sons will be colorblind?

• 0%

• 25%

• 50%

• 100%

Which best explains why males cannot be carriers of X-linked traits?

• Males only have one X chromosome

• Males have two copies of the X chromosome

• Males can be heterozygous for a particular trait

• Males do not have an X chromosome