Chapter 12Chapter 12Review SheetReview Sheet

What are the sex What are the sex chromosomes?chromosomes?

• X• Y

Sex Chromosomes of Sex Chromosomes of females?females?

• XX

Sex Chromosomes of MalesSex Chromosomes of Males• XY

A mutation where a piece of A mutation where a piece of one chromosome breaks off one chromosome breaks off

and attaches to another and attaches to another chromosomechromosome

• translocation

A change in a gene due to A change in a gene due to incorrect copyingincorrect copying

• mutation

A diagram of a family and A diagram of a family and the occurrence of traitsthe occurrence of traits

• pedigree

Blood type is controlled by Blood type is controlled by ______________ alleles______________ alleles

• multiple

What is genetic counseling?What is genetic counseling?• Risks for having kids• Should they even have kids?• Check with pedigrees and punnett

squares

What kind of trait is found in What kind of trait is found in EVERY generation?EVERY generation?

• Dominant trait

If both parents have a If both parents have a recessive trait, what is the recessive trait, what is the chance that their kids may chance that their kids may

have it too?have it too?

• 25% (1 out of 4)

Type of trait that occurs Type of trait that occurs mostly in malesmostly in males

• Sex-linked

Examples of sex-linked Examples of sex-linked disordersdisorders

• color-blindness• hemophilia

Who determines the sex of Who determines the sex of children?children?

• father

Too many or too few Too many or too few chromosomeschromosomes

• nondisjunction

When you replace a defective When you replace a defective gene with a healthy genegene with a healthy gene

• Gene therapy

A person who is heterozygous A person who is heterozygous for a trait is also called a for a trait is also called a

• carrier

What is hemophiliaWhat is hemophilia• Blood clotting disorder

What causes Down What causes Down syndrome?syndrome?

• 3 #21 chromosomes

Punnett Square with 2 parents Punnett Square with 2 parents that have a recessive gene that have a recessive gene

(not sex-linked)(not sex-linked)

Males determine sex-how?Males determine sex-how?

Punnett Square that has Punnett Square that has sex-linked traitsex-linked trait

What is Down Syndrome and What is Down Syndrome and how can a karyotype show you how can a karyotype show you

that?that?

Know how to match children Know how to match children with parents based on blood with parents based on blood

type.type.