Extension of Mendelian Genetics

Question 1

What is it called when 50% of the protein produced by a single dominant allele is sufficient to produce the dominant trait?

Answer 1

Simple Mendelian inheritance

Question 2

When a dominant allele is present but the protein is unable to exert its effects or other genes produce proteins that counteract its effects, what is that called?

Answer 2

Incomplete penetrance

Question 3

When 50% of the protein produced by a single copy of the functional allele in the heterozygote is not sufficient to produce the same trait as in homozygote making of that protein, what is it called?

Answer 3

Incomplete dominance

Question 4

What is overdominance?

Answer 4

When the heterozygote has a trait that confers greater reproductive success than either homozygote

Question 5

What is it called when the heterozygote expresses both phenotypes simultaneously? (No intermediate?)

Answer 5

Codominance

Question 6

What is the inheritance of genes located on the X-chromosome?

Answer 6

X-Linked inheritance

Question 7

What is it when the sex of the individual is able to influence their phenotype?

Answer 7

Sex-Influenced genes

Question 8

What is sex-limited inheritance?

Answer 8

This is when a trait occurs only in one sex out of the two sexes. In this inheritance pattern, sex hormones that are primarily only produced in one sex are essential for an individual to display a particular phenotype

Question 9

What is a lethal allele?

Answer 9

A lethal allele is one that has the potential to cause death to an organism

Question 10

What are the main factors that influence an organisms traits?

Answer 10

Genes and environment.

Question 11

Dominant allele, but not shown in phenoptype?

Answer 11

Incomplete penetrance

Question 12

What is norm of reaction?

Answer 12

Effects of the environment on a phenotype (i.e. arctic foxes)

Question 13

Which inheritance pattern has an intermediate?

Answer 13

Incomplete dominance

Question 14

Explain incomplete dominance at the molecular level

Answer 14

50% of the functional protein is not enough to produce the dominant trait.

Question 15

What are antigens?

Answer 15

They are molecular structures recognized by antibodies produced in the immune system

Question 16

Plasma membranes of red blood cells have groups of interconnected sugars called oligosaccharides that act as?

Answer 16

Surface antigens

Question 17

What are the surface antigens in human blood cells?

Answer 17

i, I_A and I_B

Question 18

What is hemizygous?

Answer 18

This means that males have a single copy of an X-linked gene.

Question 19

What are holandric genes?

Answer 19

Genes located on the Y chromosome

Question 20

When an allele is dominant in one sex and recessive in the other, which inheritance pattern is it?

Answer 20

Sex-influenced inheritance

Question 21

The genes that govern sex-influenced traits are?

Answer 21

Autosomal (not on the X or Y chromosome)

Question 22

Is baldness a sex-influenced inheritance pattern?

Answer 22

No, it isn’t. It is X-linked.

Question 23

What is an example of sex-influenced inheritance pattern?

Answer 23

Scurs in cattle

Question 24

The genes that affect sex-limited must be?

Answer 24

Autosomal or X-linked

Question 25

Sex-limited traits are responsible for?

Answer 25

Sexual dimorphism

Question 26

What is sexual dimorphism?

Answer 26

This is the reason we have, male and female, different morphological traits.

Question 27

What is an essential gene?

Answer 27

This is a gene that codes a protein that is needed for the survival of the organism and in its abscence, leads to the death of the organism.

Question 28

Semilethal alleles?

Answer 28

These are lethal alleles that are lethal only in some individuals

Question 29

What is pleiotropy?

Answer 29

When expression of a single gene has two or more phenotypic effects

Question 30

What is gene interaction?

Answer 30

Allelelic variants of two different genes affect a single trait.

Question 31

what is epistasis?

Answer 31

When the allele of one gene mask the effects of another

Question 32

What is gene redundancy?

Answer 32

When a gene compensates for the lack of function of another gene

Question 33

which antigen does a person with type O blood produce?

Answer 33

They produce the H-antigen

Question 34

Why is the oligosaccharide smaller in type O blood?

Answer 34

Because a sugar has not been attached to a specific site on the oligosaccharide. This is because the i allele (allele for type O) carries a loss of function allele that renders the protein ineffective and unable to aid the binding/attachment of a sugar to the oligosaccharide)

Question 35

What protein is encoded by the surface antigens I_A and I_B?

Answer 35

glycosyl transferase

Question 36

What deos glycosyl transferase recognize in I_A and I_B

Answer 36

I_A: uridine diphosphate N-acetylgalactosamine and attaches N-acetylgalactosamine to the oligosaccharide

I_B: UDP-galactose and attaches galactose to the oligosaccharide

Question 37

what is a gene knowckout?

Answer 37

this is when gene is made to deliberatly lose its function. They don’t usually have an effect because of gene redundancy

Question 38

what does a different complementation group mean?

Answer 38

It means different genes.