Chapter 3.1: Extension to Mendel for Single-Gene Inheritance

Question 1

Define multiple alleles

Answer 1

gene with more than 2 alleles

Question 2

What is a gene with only one common, wild-type allele?

Answer 2

monomorphic

Question 3

How many alleles does each of the 3 histocompatibility genes have?

Answer 3

 Each of the 3 genes (HLA-A, HLA-B, HLA-C) has 400-1200 alleles

Question 4

What determines whether 2 alternative alleles of a single gene show complete dominance, incomplete dominance, or codominance?

Answer 4

 Whether 2 alternative alleles of a single gene show complete dominance, incomplete dominance, or codominance depends on the kinds of proteins determined by the alleles and the biochemical function of those proteins in the cell

Question 5

What is a gene with more than 2 alleles?

Answer 5

multiple alleles

Question 6

What is special about the Type AB blood type?

Answer 6

• Considered universal recipients, because they make neither anti-A nor anti-B antibodies, which if present, would target the surface molecules of incoming blood cells

Question 7

What is the dominance series for lentil seed coat patterns?

Answer 7

 Dominance Series: marbled-1 > marbled-2 > spotted = dotted > clear

Question 8

What are the 5 alleles for lentil seed coats?

Answer 8

 5 alleles: spotted, dotted, clear (pattern absent), and 2 types of marbled

Question 9

What are traits determined by 2 or more genes?

Answer 9

multifactorial

Question 10

Define codominant

Answer 10

trait shows up equally in the phenotype

Question 11

What cause sickle-cell disease?

Answer 11

o Sickle-cell disease is the result of a faulty hemoglobin molecule

Question 12

What are chance alternatives of the genetic material?

Answer 12

mutation

Question 13

What are genes with more than one common allele?

Answer 13

polymorphic

Question 14

Define mutation

Answer 14

chance alternatives of the genetic material

Question 15

Define polymorphic

Answer 15

genes with more than one common allele

Question 16

Define allele frequency

Answer 16

percentage of the total number of gene copies the allele accounts for

Question 17

What type of antibodies does a Type AB blood type produce?

Answer 17

 Type AB make neither antibody

Question 18

What type of antibodies does a Type O blood type produce?

Answer 18

 Type O produce both anti-A and anti-B antibodies

Question 19

What is a trait is intermediate of parents?

Answer 19

incomplete dominance

Question 20

What are the 3 alleles for ABO blood type?

Answer 20

 The gene for the ABO blood types has 3 alleles: I^A, I^B, and i

Question 21

What do the antibodies in blood do?

Answer 21

 These antibodies cause coagulation of cells displaying foreign molecule

Question 22

What is the most common allele in population; allele present in the population at a frequency greater than 1%?

Answer 22

wild-type allele (+)

Question 23

What type of antibodies does a Type A blood type produce?

Answer 23

 Type A produces anti-B antibodies

Question 24

What type of antibodies does a Type B blood type produce?

Answer 24

 Type B produces anti-A antibodies

Question 25

Define wild-type alleles (+)

Answer 25

most common allele in population; allele present in the population at a frequency greater than 1%

Question 26

What is the role of histocompatibility antigens in humans and where are they located?

Answer 26

 Carried by all of the body’s cells except the red blood cells and sperm, histocompatibility antigens play a critical role in facilitating a proper immune response that destroys intruders while leaving the body’s own tissues intact

Question 27

Relate sickle-cell disease to pleitropy

Answer 27

 The Hbβ^S allele of the β-globin gene affects more than one trait

Question 28

Define pleitropy

Answer 28

the phenomenon of a single gene determining a number of distinct and seemingly unrelated characteristics

Question 29

What is special about the Type O blood type?

Answer 29

• Considered universal donors because their red blood cells carry no surface molecules that will stimulate an antibody attack in a transfusion recipient

Question 30

What is the phenomenon of a single gene determining a number of distinct and seemingly unrelated characteristics?

Answer 30

pleiotropy

Question 31

Define mutant allele

Answer 31

a rare allele in the population

Question 32

Relate sickle cell disease to multiple alleles

Answer 32

 The β-globin gene has a normal wild-type allele (Hbβ^A) that gives rise to fully functional β-globin, as well as 400 mutant alleles

Question 33

What is trait shows up equally in the phenotype?

Answer 33

codominant

Question 34

What is a rare allele in the population?

Answer 34

mutant allele

Question 35

Define multifactorial

Answer 35

traits determined by 2 or more genes

Question 36

Define incomplete dominance

Answer 36

trait is intermediate of parents

Question 37

Define monomorphic

Answer 37

a gene with only one common, wild-type allele

Question 38

What is an an allele that negatively affects the survival of a homozygote?

Answer 38

recessive lethal allele

Question 39

Define common variants

Answer 39

high-frequency alleles of a polymorphic gene

Question 40

Define recessive lethal allele

Answer 40

an allele that negatively affects the survival of a homozygote

Question 41

What is the percentage of the total number of gene copies the allele accounts for?

Answer 41

allele frequency

Question 42

What is the high-frequency alleles of a polymorphic gene?

Answer 42

common variants