Sex-linked traits notes

What are sex-linked traits?

Traits controlled by genes located on sex chromosomes, mainly the X chromosome.

Difference between X-linked and Y-linked traits

X-linked traits are on the X chromosome; Y-linked traits are on the Y chromosome.

True or false: Hemophilia is a sex-linked trait.

True, because it is an X-linked recessive disorder.

Fill in the blank: Color blindness is a common ___ trait.

X-linked recessive

Who is more likely to express X-linked traits?

Males, because they have only one X chromosome.

What is a carrier in genetics?

An individual who has one copy of a recessive allele for a trait but does not express it.

Example of a genetic disorder caused by an X-linked trait

Hemophilia or Duchenne muscular dystrophy.

True or false: Females can never be affected by X-linked traits.

False, because females can be affected if they inherit two copies of the allele.

What does it mean if a male has an X-linked trait?

He expresses the trait since he has only one X chromosome.

Difference between dominant and recessive X-linked traits

Dominant traits require one copy to be expressed; recessive traits require two copies in females.

What is a Punnett square used for?

To predict the genotypes and phenotypes of offspring from genetic crosses.

True or false: Both parents contribute equally to sex-linked traits.

False, mothers can pass X-linked traits to sons, but fathers cannot pass X-linked traits to sons.

Fill in the blank: Males have one X and one ___ chromosome.

Y