Chapter 8 - Sex Link Disorders

Question 1

If there is a x chromosome recessive disorder, who is ALWAYS affected?

Answer 1

If a male is passed a x recessive disorder, it is always present because there is only one x.

Question 2

In theory (punette square), a male with a x recessive disorder reproduces with a “normal” female. Who is affected? What would the offspring look like?

Answer 2

All females are affected are effected, no males will be affected.

Question 3

In theory (punette square), a phenotypically normal female with x recessive disorder reproduces with a “normal” male. What would the offspring look like?

Answer 3

50% of male offspring will have it, and 50% of the female offspring will be a carrier.

Question 4

In theory (punette square), an affected female who has a x recessive disorder reproduces with a “normal” male. What would the offspring look like?

Answer 4

All the females are carriers, all the males will be affected.

Question 5

In a x dominant disorder, whether it be the male or the female is affected reproduced with a “normal” partner. What would the offspring look like?

Answer 5

All would be affected and would have the disease present.

Question 6

If there is a y linked disorder, is it possible for a female to be affected?

Answer 6

No.

Question 7

If there is a y inked disorder, is it possible for a male to be just acarrier and not actually have the disease?

Answer 7

No, due to the fact that there is only one y in the genotype of a male, it is always present.

Question 8

What is an example of a x recessive disorder? What are the symptoms?

Answer 8

Hemophilia:

-no clotting of blood vessels

Question 9

What is an example of a x dominant disorder? What are the symptoms?

Answer 9

Aicardi Syndrome:

• infantile spasms
• effects brain development
• present as early as 3 months

Question 10

What is an example of a x dominant disorder? What are the symptoms?

Answer 10

Aicardi Syndrome:

• infantile spasms
• effects brain development
• present as early as 3 months

Question 11

What is an example of a y disorder? What are the symptoms?

Answer 11

Azoospermia:

- the inability to produce sperm

Question 12

What is the definition of Chromosomal Disorders?

Answer 12

The addition or deletion of entire chromosomes.

Question 13

Name some examples of a Chromosomal Disorder?

Answer 13

Down’s Syndrome
‘Super-male’
Kleinfeter

Question 14

What causes Down’s Syndrome

Answer 14

“Trisomy 21” or an extra copy of the 21st chromosme

Question 15

What is the genotype of a “supermale”?

Answer 15

xyy

Question 16

What is the genotype of people who have kleinfeter?

Answer 16

xxy