Topic 12: Genotype, Phenotype And Inheritance

Question 1

What is the definition of genotype?

Answer 1

DNA sequence of a individual which determines the specific characteristics or phenotype of that person

Question 2

What is the definition of phenotype?

Answer 2

An organism’s observable physical and biochemical characteristics directly influenced by the genotype and/or environment

Question 3

What is the definition of gene?

Answer 3

A stretch of DNA sequence at a specific chromosomal location that carries the code for a polypeptide or untranslated RNA

Question 4

What is the definition of allele?

Answer 4

A version or variant of a gene

Question 5

If 2 individuals are affected (autosomal recessive), how much of their offsprings will be affected?

Answer 5

100%

Question 6

If 2 heterozygotes or carriers (autosomal recessive) had offsprings, what are the chances that their offspring will be affected?

Answer 6

25%

Question 7

Are males and females equally affected by autosomal recessive?

Answer 7

Yes

Question 8

Can autosomal recessive diseases skip generations?

Answer 8

Yes

Question 9

Are both the parents of a individual with an autosomal recessive disease carriers?

Answer 9

Yes

Question 10

What is an example of a autosomal recessive disease?

Answer 10

Cystic fibrosis

Question 11

What are the chances of having affected offspring if an individual is affected by an autosomal dominant disease?

Answer 11

50% no matter the partner is affected or not

Question 12

Are males and females equally affected by autosomal dominant diseases?

Answer 12

Yes

Question 13

Are both of the parents of an affected individual with autosomal dominant disease affected as well?

Answer 13

No, just one of them needs to be affected

Question 14

Can autosomal dominant diseases skip generations?

Answer 14

No, they’re found in every generation

Question 15

What is an example of a autosomal dominant disease?

Answer 15

Huntington’s disease

Question 16

Are males and females equally affected by X-linked recessive diseases?

Answer 16

No

Question 17

Are the parents of a affected male with X-linked recessive disease affected as well?

Answer 17

Mother must at least be a carrier, dad doesn’t have to be

Question 18

Are the parents of an affected female with X-linked recessive disease affected as well?

Answer 18

Father affected, mom at least a carrier

Question 19

Are the offsprings of an affected male with X-linked recessive disease affected as well?

Answer 19

They will at least be carriers

Question 20

Are males and female equally affected by X-linked dominant diseases?

Answer 20

Yes

Question 21

Are females and males equally affected by Y-linked diseases?

Answer 21

No only male

Question 22

What is mitochondrial inheritance?

Answer 22

All individuals inherit mitochondria from mother

Question 23

What is polygenic inheritance?

Answer 23

More than one gene involved in producing a phenotype

Question 24

What is multi factorial inheritance?

Answer 24

Genetic and environmental factors contribute to the trait