*Unit 5: Sex-Linked Crosses and Pedigrees

Question 1

Sex-linked genes

Answer 1

Genes found of the X Chromosome

Question 2

_____ are XY.

Answer 2

Males

Question 3

_____ are XX.

Answer 3

Females

Question 4

How many copies of genes do males have on the X Chromosome?

Answer 4

1 copy

Question 5

How many copies of genes do females have on the X Chromosome?

Answer 5

2 copies

Question 6

Recessive genes on the X chromosome show up more in _____.

Answer 6

males

Question 7

Hemophilia

Answer 7

A disorder that causes blood to clot incorrectly, causing patients to bleed from minor cuts

Question 8

Hemophilia is common in royal families because of _____.

Answer 8

inbreeding

Question 9

Red-green color blindness is most common in _____.

Answer 9

males

Question 10

List human examples of sex linkage.

Answer 10

~Hemophilia
~Red-green color blindness
~Male pattern baldness

Question 11

What are the parent genotypes of a heterozygous red-eyed female and a red-eyed male?

Answer 11

X(^R) X(^r) * X(^R) Y

Question 12

Pedigree

Answer 12

Shows how a trait is passed down in an family

Question 13

Carrier

Answer 13

~Indiviual who has 1 copy of a recessive allele
~doesn’t have disease
~Not always shown on pedigrees

Question 14

Pedigree symbol for female.

Answer 14

A blank/white circle

Question 15

Pedigree symbol for male.

Answer 15

A blank/white square

Question 16

Pedigree symbol for affected female.

Answer 16

A filled in/black circle

Question 17

Pedigree symbol for affected male.

Answer 17

A filled in/black square

Question 18

Pedigree symbol for female carrier.

Answer 18

A half white, half black circle

Question 19

Pedigree symbol for male carrier.

Answer 19

A half white, half black square

Question 20

If a trait is seen more in males, the gene is _____.

Answer 20

sex-linked

Question 21

If a trait is relatively even between males and females, the gene is _____.

Answer 21

autosomal

Question 22

If a person has a disease and neither parent had the disease, it must be _____.

Answer 22

recessive

Question 23

If carriers in a pedigree are shown, it must be a _____ trait.

Answer 23

recessive