Chapter 5.3

Question 1

Hemophilia

Answer 1

referred to as the “royal disease” due to its spread to the royal families of Europe through Queen Victoria’s descendants

Question 2

What is hemophilia?

Answer 2

the inability to form blood clots to prevent bleeding out

Question 3

Chromosome theory of inheritance

Answer 3

• genes are located at specific positions on chromosomes
• segregation and assortment of these chromosomes during meiosis is responsible for inheritance patterns

Question 4

Gene locus (gene loci)

Answer 4

site on a chromosome that a specific gene occupies

Question 5

Who does hemophilia affect?

Answer 5

Mostly males, 1 in 10,000

Question 6

Where do alleles of a gene reside on homologous chromosomes?

Answer 6

at the same locus

Question 7

What makes an organism heterozygous/homozygous

Answer 7

homologous chromosomes having same/different alleles at a particular locus

Question 8

Genetic linkage

Answer 8

tendency for alleles for different genes on the same chromosome to be inherited together

Question 9

Linked genes

Answer 9

genes with loci that are close together

Question 10

Recombination frequency

Answer 10

frequency with which certain genes turn up together

Question 11

What is recombination frequency used for?

Answer 11

to map distance between gene loci on a chromosome

Question 12

Gene map

Answer 12

diagram that shows relative locations and distances of genes on a chromosome

Question 13

Where is the gene involved in white eye inheritance found?

Answer 13

on the x chromosome

Question 14

If genes are located on separate chromosomes…

Answer 14

they assort independently during meiosis

Question 15

If genes are located on the same chromosomes…

Answer 15

less likely to assort independently

Question 16

What is the only way that alleles assort independently?

Answer 16

if they separate during crossing over

Question 17

The closer genes are on a chromosome (black and gray fruit flies)

Answer 17

the greater degree of genetic linkage

Question 18

Where were the first studies of gene mapping done?

Answer 18

Fruit flies

Question 19

Who discovered sex-linked genes

Answer 19

Thomas Hunt Morgan

Question 20

What genes do fruit flies have relationship in?

Answer 20

Sex and eye colour

Question 21

What colour eye is rare for fruit flies?

Answer 21

White

Question 22

Sex-linked gene

Answer 22

any gene located on a sex-chromosome

Question 23

Hemophilia (blood fails to clot normally) is also called

Answer 23

bleeder’s disease

Question 24

Fruit fly model

Answer 24

shows why recessive sex-linked traits are so much more common in males than females

Question 25

Duchenne muscular dystrophy

Answer 25

immune system disorder which is x-linked - causes progressive muscle weakness

Question 26

Y-linked disorders

Answer 26

caused by mutations in genes located on the Y-chromosome

Question 27

Sex determining region (SRY)

Answer 27

gene for testis determining factor

Question 28

How much does red-colour blindness affect males?

Answer 28

4-8%

Question 29

How much does red-colour blindness affect FEMALES

Answer 29

0.4%

Question 30

What do mutations in SRY result in?

Answer 30

XY females who cannot develop reproductive system