Modes Of Inheritance

Question 1

What is an autosomal dominant condition?

Answer 1

A condition where only one faulty allele is needed for the condition to be expressed

Question 2

Who do autosomal dominant conditions manifest in?

Answer 2

They mainfest in heterozygotes

Question 3

What are the effects of autosomal dominant conditions?

Answer 3

1. Gain of function
2. Insufficient amounts of protein being produced
3. Dominant negative effect

Question 4

What is an example of an autosomal dominant condition?

Answer 4

Huntingtons

Question 5

What type of pedigree pattern do autosomal dominant conditions show?

Answer 5

Vertical pedigree pattern

Question 6

What causes Huntingtons disease?

Answer 6

expansion of a CAG repeat which results in mutant proteins being produced which interfere with the functioning of normal nerve cells

Question 7

What is meant by gain of function?

Answer 7

Gain of function is where the protein becomes hyperactive, and it is this hyperactivity which results in the onset of the disease

Question 8

What is meant by a dominant negative effect?

Answer 8

Dominant negative effect is where the protein produced interferes with the functioning of the normal protein

Question 9

How do autosomal dominant conditions effect men and women?

Answer 9

They affect men and women equally

Question 10

What are autosomal recessive conditions?

Answer 10

where you need two copies of the allele in order for the condition to be expressed

Question 11

What are the usual effects of autosomal recessive conditions?

Answer 11

Loss of function - having both copies results in a completely malfunctioning protein

Question 12

What type of pedigree pattern do autosomal recessive conditions show?

Answer 12

Horizontal pedigree

Question 13

What can increase the risk of autosomal recessive conditions?

Answer 13

Consangious marriages

Question 14

Why can autosomal recessive conditions skip generations?

Answer 14

Due to the high chance of being a carrier

Question 15

How are men and women affected with autosomal recessive conditions?

Answer 15

They are affected equally

Question 16

What type of chromosomes are autosomal recessive genes located on?

Answer 16

Non-sex chromosomes

Question 17

What percentage of DNA is shared between first cousins?

Answer 17

12.5%

Question 18

Who do X-linked recessive conditions mainly affect?

Answer 18

Men

Question 19

How can females have an X linked recessive condition?

Answer 19

They have to be homozygous for the condition

Question 20

What is the chance of a daughter of an affected male being a carrier of an X Linked recessive condition?

Answer 20

100%

Question 21

What is an X linked recessive condition?

Answer 21

Where the alleles are located on the sex chroosomes, and since males have XY, a portion of their second chromosome is missing, meaning males have an increased risk of the condition as if they only need the one recessive allele to have the condition

Question 22

What happens to the daughters and sons of an affected father and unaffected mother of an X linked dominant condition?

Answer 22

Daughters - They are all affected
Sons - none affected

Question 23

Who do Y linked disorders affect?

Answer 23

Only men as females do not have Y chromosome

Question 24

What type of pedigree pattern do Y linked disorders show?

Answer 24

Vertical patern with only males affected

Question 25

Who are all your mitochondria inherited from?

Answer 25

Mother

Question 26

A mother has a mitochondrial condition. What happens to her children?

Answer 26

They are all affected

Question 27

Why do the expression of mitochondrial conditions vary massively in a family?

Answer 27

When the mitochondria replicate, genes can be lost or gained meaning there is an enourmous amount of variation

Question 28

What type of inheritance is it when children of unaffected parents are affected?

Answer 28

X Linked recessive

Question 29

What type of inheritance is it when all children of an affected mother are affected?

Answer 29

Mitochondrial