Question 1

What is an autosomal chromosome (autosome)?

Accepted Answer

Any numbered chromosome that is not a sex chromosome

Question 2

What is a wild-type phenotype?

Accepted Answer

Typical/most-common phenotype for a trait in a given species

(opposite of a mutant phenotype)

Question 3

What is a mutant phenotype?

Accepted Answer

Traits that are different from the normal for a given species

(opposite of wild-type)

Question 4

What are sex-linked traits?

Accepted Answer

Genetic characteristics determined by genes on sex chromosomes

(often affect one gender much more than the other; e.g., DMD, hemophilia, red-green color blindness)

Question 5

Why are do some genetic disorders affect one gender more than the other?

Accepted Answer

Some genetic disorders have a recessive allele on the X chromosome

Women have two X chromosomes, while men only have one, so women have to get two copies of the gene to have the disorder

Question 6

What is Duchenne muscular dystrophy (DND)?

Accepted Answer

A sex-linked disorder caused by the absence of an essential muscle protein, causing loss of strength and coordination

(much more common in men)

Question 7

What is hemophilia?

Accepted Answer

A sex-linked disorder caused by the absence of a protein vital to clotting blood

(much more common in men)

Question 8

What is red-green color blindness?

Accepted Answer

A sex-linked disorder that causes the inability to distinguish red and green

(more common in men)

Question 9

What is X inactivation?

Accepted Answer

A process females undergo during embryonic development, where cells randomly inactivate one of the two X chromosomes

(the inactivated X chromosome is known as the Barr body)

Question 10

What is Barr body?

Accepted Answer

The inactivated X chromosome in all female cells, as a result of X inactivation

Question 11

What are holandric traits?

Accepted Answer

Traits inherited via the Y chromosome, only affecting males

(hypertrichosis pinnae, which causes excessive hair in the ear, only affects males)

Question 12

What are linked genes?

Accepted Answer

Genes likely to be inherited together because they lie physically close on the same chromosome

(do not follow Mendel's law of independent assortment)

Question 13

Why are linked genes less susceptible to being mixed up by crossover?

Accepted Answer

Linked genes are physically close to each other, so crossover is less likely to affect them

Question 14

What is a linkage map?

Accepted Answer

Tables to visualize the order and relative frequency of genes on a chromosome

(created by finding recombination frequencies for gene pairs)

Question 15

What is a centimorgan (map unit)?

Accepted Answer

A unit for measuring genetic linkage

(one centimorgan is equal to 1% crossover frequency)

Non-Mendelian Genetics, AP Biology Flashcards