Genetic Processes Exam Review

What is monosomy?

A chromosomal disorder where an individual is missing one chromosome (2n - 1).

What is an example of monosomy?

Turner syndrome, which only affects females.

What is trisomy?

A disorder wehre an individual has an extra chromosome (2n + 1).

What is an example of trisomy?

Down syndrome, which causes delayed function.

What is a karyotype?

A picture of chromosomes arranged in pairs by size and shape to detect abnormalities.

What can a karyotype identify?

Extra/missing chromosomes and chromosomal disorders.

What is crossing-over?

Exchange DNA between homologous chromosomes during prophase I of meiosis.

Why is crossing over important?

Increases genetic diversity.

What is the Law of Dominance?

Dominant alleles mask recessive alleles.

What is the law of segregation?

The 2 alleles encoding a trait are packaged into separate gametes.

What is the law of independent assortment?

The inheritance of alleles for one trait does not affect the inheritance of alleles for another trait.

What is amniocentesis?

Testing fetal cells from amniotic fluid to detect genetic disorders.

What is chorionic villus sampling (CVS)?

Taking placental tussue for genetic testing earlier in pregnancy.

What is genetic screening?

Testing for genetic diseases for carrier status.

What is genotype?

The genetic makeup (AA, Aa, aa).

What is a gene locus?

The location of a gene on a chromosome.

What is a test cross?

Crossing an unknown dominant individual with a homozygous recessive to determine genotype.

What are multiple allele?

More than two possible alleles exist in a population.

Why are males more affected by x-linked disorders?

Males only have one X chromosome, so recessive traits are expressed more easily.

Key trait of X-linked dominant disorders?

Affected fathers pass trait to all daughters, not sons.

Key trait of X-linked recessive disorders?

Mostly affects males; females are often carriers.