Complexities Relating Genotype to Phenotype

Question 1

What is wild type allele?

Answer 1

Functional protein

Question 2

What is mutant allele?

Answer 2

Often non-functional or unstable protein

Question 3

Where can you find wild type and mutant allele?

Answer 3

In diploids

Question 4

Finish the sentence:

Many wild type alleles are…

Answer 4

Dominant

Question 5

Finish the sentence:

Many mutant type alleles are…

Answer 5

recessive

Question 6

What is a problem that can occur with dominant alleles?

Answer 6

They aren’t always complete

Question 7

Define incomplete dominance:

Answer 7

heterozygotes show an intermediate phenotypes

Question 8

Give an example of incomplete dominance:

Answer 8

red and white flowers can produce pink flowers

Question 9

Define co-dominance:

Answer 9

heterzogyotes show phenotype of both allels

Question 10

Give an example of co-dominance

Answer 10

Blood

Question 11

Define multiple alleles:

Answer 11

More than two alleles for a gene

Question 12

What do multiple allele establish?

Answer 12

Dominance hierarchy

Question 13

Define pleiotropy:

Answer 13

One gene contributes to more than one trait

Question 14

Give an example of pleiotropy:

Answer 14

Genes involved in cilia and flagella

Question 15

Define lethal alleles:

Answer 15

Gene which if contains both of lethal gene will produce not be born

Question 16

What is the problem with lethal alleles?

Answer 16

Cause skewed phenotypic ratios

Question 17

What is sickle-cell syndrome an example of?

Answer 17

Dominance and pleiotropy

Question 18

Is sickle-cell physiological levels co-dominance or incomplete dominance?

Answer 18

incomplete dominance

Question 19

Is sickle-cell biochemical levels co-dominance or incomplete dominance?

Answer 19

co-dominace

Question 20

What can gene combinations rise?

Answer 20

Novel phenotypes

Question 21

How many major genes at least determine coat colour in mammals?

Answer 21

5

Question 22

Define epistasis:

Answer 22

A gene interaction in which the effects of an allele at one gene hide the effects of alleles at another gene

Question 23

What can complementation tests determine?

Answer 23

Determine if a phenotype arises from mutations in the same or separate genes

Question 24

What does penetrance measure?

Answer 24

The percentage of individuals with a given genotype who exhibit the phenotype associated with the genotype

Question 25

What does expressivity measure?

Answer 25

Extent to which given genotype is expressed at the phenotypic level

Question 26

Main interactions between alleles of a gene:

Answer 26

• Dominance
• Incomplete dominance
• Co-dominance
• Pleitropy
• Lethal alleles

Question 27

Main interactions between genes:

Answer 27

• Gene combinations
• Epistasis
• Genetic complementation tests