Inheritance

Question 1

What is inheritance?

Answer 1

The acquisition of characteristics or qualities by transmission from parent to offspring

Question 2

How are traits passed on?

Answer 2

By factors

Question 3

What is the law of segregation?

Answer 3

When alleles in each parental plant segregate from one another during formation of reproductive cells

Question 4

How do alleles exists?

Answer 4

In pairs

Question 5

What is a allele?

Answer 5

Alternative form of a gene

Question 6

Observed traits are called

Answer 6

Phenotype

Question 7

What is a Recessive trait?

Answer 7

It doesn’t show up in an individual can still be passed to the next generation

Question 8

Each single phenotype still exhibits what ratio?

Answer 8

3:1

Question 9

What is the law of independent assortment?

Answer 9

Traits are inherited independently of each other

Question 10

Location of a gene

Answer 10

Locus

Question 11

What are the five basic patterns of inheritance?

Answer 11

Mendelian pedigree patterns

Question 12

Name them (pedigree)

Answer 12

1. X linked recessive
2. X linked Dominant
3. Autosomal Dominant
4. Y linked
5. Autosomal Recessive

Question 13

Characteristics of Autosomal Dominant?

Answer 13

1. Affects all generations (multiple)
2. Affects male and female
3. Can be passed from any gender
4. Affected child has affected parent

Question 14

Example of Autosomal Dominant Diseases

Answer 14

Huntingtons and Achondroplasia

Question 15

Numerals uses

Answer 15

YOU KNOW THIS

Question 16

Characteristics of Autosomal Recessive Disease

Answer 16

1. Affects any gender
2. Parents are usually unaffected
3. Parent is a carrier of the disease

Question 17

Example of Autosomal Recessive Pattern

Answer 17

Cystic fibrosis and sickle cell anemia

Question 18

X linked Recessive Characteristics

Answer 18

1. Affects mainly males
2. No male to male transmission
3. Mother is normally a asymptomatic carrier
4. Parents usually unaffected

Question 19

Examples of X- linked Recessive Pattern?

Answer 19

Haemophilia A, Red green color blindness

Question 20

Characteristics of X linked Dominant Pattern

Answer 20

Mating of affected male and normal female: All daughters affected and all sons normal
Mating of affected female and normal male: All offspring’s have a 50% chance of getting the disease

Question 21

Example of X linked Dominant disease

Answer 21

Incontinentia pigmenti

Question 22

Complications to Mendelian inheritance

Answer 22

1. Skewed X- inactivation
2. Incomplete penetration
3. Linkage
4. Mitochondrial inheritance
5. New mutations (mosaicism)
6. Late onset disease
7. Parental origin (imprinting)
8. Lethal alleles
9. Variable expression

Question 23

What is Skewed X-inactivation?

Answer 23

One mechanism by which women may be affected by an x-linked recessive disease while having just one mutant copy of the allele

Question 24

What is Mitochondrial inheritance?

Answer 24

All offspring of affected of mother are affected. Affected father cannot transmit disease. Mutations in mitochondrial DNA

Question 25

What causes the Mitochondrial inheritance

Answer 25

Ovum has a lot of mitochondria Sperm very little cytoplasm

Question 26

What does linkage violate?

Answer 26

Mendel’s law of independent assortment

Question 27

What is incomplete penetrance?

Answer 27

Individual inherits the mutant gene but does not express the disease

Question 28

What is late onset disease?

Answer 28

Mutant allele inherited but disease not present at birth

Question 29

Examples of late onset

Answer 29

Huntington’s disease, hereditary cancers

Question 30

What is variable expression?

Answer 30

All patient express the disease but they may express all symptoms or only a few

Question 31

Example of variable expression?

Answer 31

Marfan’s syndrome