Inheritance And Disease

Question 1

Where do you inherit mitochondrial DNA come from

Answer 1

All mitochondria/mitochondrial DNA is inherited from the mother

Question 2

What does imprinting mean

Answer 2

One allele is active while the other is inactive

Question 3

What is mosaicism

Answer 3

An error in cell division, the same cells have different genetic make up

Question 4

What does Mendelian inheritance mean

Answer 4

Mendelian inheritance refers to certain patterns of how traits are passed from parents to offspring

Question 5

What are the different types of Mendelian inheritance

Answer 5

Autosomal recessive
Autosomal dominant
X-linked

Question 6

How does an autosomal recessive manifest

Answer 6

An autosomal recessive disease manifests in a homozygous state

Question 7

For offspring to inherit a autosomal recessive how many defective genes do they need to inherit

Answer 7

For an autosomal recessive disease to be inherited 2 defected genes need to be inherited 1 from each parent

Question 8

What is the chance of getting an autosomal recessive disease

Answer 8

25%

Question 9

What is the chance of been a carrier of an autosomal recessive disease

Answer 9

50%

Question 10

What is the chance of an affected child’s sibling been a carrier of an autosomal recessive disease

Answer 10

66.6%

Question 11

Who is more affected by autosomal recessive disease

Answer 11

Males and females are affected equally

Question 12

What is an example of an autosomal recessive disease

Answer 12

Cystic fibrosis

Question 13

What does a autosomal dominant disease manifest in

Answer 13

An autosomal dominant disease manifests in a heterozygous state

Question 14

Who is affected most by autosomal dominant diseases

Answer 14

Males and females are affected equally

Question 15

Does autosomal dominant disease affect single or multiple generations

Answer 15

Multiple generations

Question 16

Why can an offspring get a autosomal dominant disease if the parents are unaffected

Answer 16

Gonadal mosaicism
Mother has reduced penetrance
Mother has variable expression

Question 17

How many defect genes do you need to inherit a autosomal dominant disease

Answer 17

Only one gene is needed so a 50% chance that offspring can be affected

Question 18

What is an example of an autosomal dominant disease

Answer 18

Huntingtons disease

Question 19

What causes an x-linked disease

Answer 19

Caused by a mutation on the X chromosomes

Question 20

How is an x-linked disease passed to offspring

Answer 20

The transmission of an x-linked is never male to male because the son will get the X chromosome from the mother so transmission will be female to male

Question 21

Who is more affected by x-linked diseases

Answer 21

Males are more affected
Females will be carriers of the disease but wont suffer

Question 22

Are x-linked diseases recessive or dominant

Answer 22

X-linked diseases can be both recessive and dominant

Question 23

What is an example of a recessive x-linked disease

Answer 23

Duchennes muscular dystrophy

Question 24

What is an example of a dominant x-linked disease

Answer 24

Alports syndrome

Question 25

What does homozygous mean

Answer 25

A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes

Question 26

What does heterozygous mean

Answer 26

Diploid organism is heterozygous at a gene locus when its cell contains two different alleles of a gene

Question 27

What could be the cause of a disease

Answer 27

Genetic cause
Multifactorial cause
Environmental cause

Question 28

What are examples of genetic diseases

Answer 28

Down syndrome
Cystic fibrosis
Huntingtons disease
Haemophilia

Question 29

What are examples of multifactorial diseases

Answer 29

Spina bifida
Cleft palate
Diabetes
Schizophrenia

Question 30

What are examples of environmental factors which could causes disease

Answer 30

Poor diet
Infection
Drugs
Accident