Chapter 3

Question 1

1) When an F1 hybrid does not resemble either pure breeding parents
2) Intermediate phenotype where both parental alleles contribute to the phenotype
3) 1:2:1 phenotypic ratio exactly reflects the genotype can ratio
4) recessive may not be expressing a viable protein (snap dragons)

Answer 1

Incomplete dominance

Question 2

1) Both traits show up equally in the heterozygotes phenotype in the F1 cross (spotted dotted lentils) 2)1:2:1 in the F2 generation 3) blood group alleles (a and b sugars)

Answer 2

Codominant

Question 3

Novel phenotype determined by 2 or more genes, or from interactions between genes and the environment (green lentils) 9:3:3:1

Answer 3

Multifactorial

Question 4

A given gene may have more than two alleles.

Sugar adding enzyme in blood

Answer 4

Multiple alleles

Question 5

Alleles are listed in order from most to least dominant

Answer 5

Dominance series

Question 6

Chance alterations of the genetic material that are spontaneous in nature

Answer 6

Mutations

Question 7

Percentage of the total number of gene copies

Answer 7

Allele frequency

Question 8

The most common alleles of each gene In a population, or if present, at a frequency of greater than 1%, often designated +

Answer 8

Wild type

Question 9

Rare allele

Answer 9

Mutant allele

Question 10

A gene with only one common wild type allele,
Agouti,
More than 99% frequency

Answer 10

Monomorphic

Question 11

Some genes have more than one common allele,

ABO blood type system

Answer 11

Polymorphic

Question 12

High frequency alleles of a polymorphic gene,

ABO blood type system

Answer 12

Common variants

Question 13

When a single gene determines a # of distinct and seemingly unrelated characteristics,

Mutations can influence multiple biochemical processes

Answer 13

Plieotropy

Question 14

An allele that negatively affects the survival of a Homozygote, 1:2 phenotypic ratio indicates a missing genotype

Answer 14

Recessive lethal alleles

Question 15

Extension: Incomplete dominance or codominance,
On crossing F1, Phenotypes are 1:2:1,
Unlike either Homozygote

Answer 15

Extension to complete dominance

Question 16

Extension: multiple alleles
Multiplicity of Phenotypes
Series of 3:1 ratios

Answer 16

Extension to two alleles

Question 17

Extension: recessive lethal alleles
2:1 instead of 3:1
Heterozygotes survive but may have visible Phenotypes

Answer 17

Extension to all alleles are equally viable

Question 18

Extension: Plieotropy,

One gene affects Several traits, affected several ways depending on dominance relationships, Different ratios

Answer 18

Extension to one gene determines one trait

Question 19

Two genes working in tandem To produce purple sweet pea flowers, a dominant allele of each gene (producing white flowers) must be present (in opposite parents) to produce that color
9:7 in the F2; A-B- is the only purple phenotype

Answer 19

Complementary gene action

Question 20

A gene interaction in which the effects of an allele at one gene hide the effects of alleles at another gene. Can be either dominant or recessive.

Answer 20

Epistasis

Question 21

Homozygous for a recessive allele of the second gene is required to hide the effects of another gene to cause a masking phenomenon

9:3:4 in Chocolate labs

Answer 21

Recessive Epistasis

Question 22

Dark color in dog coats

Answer 22

Eumelanin

Question 23

Light color of dog coats

Answer 23

Pheomelanin

Question 24

Epistasis when the dominant allele of one gene hides the effects of another gene

Chickens

Answer 24

Dominant Epistasis

Question 25

15:1 | Specify nearly identical proteins that perform the same function

Answer 25

Redundant gene action

Question 26

One dominant allele of each of 2 genes is Necessary to produce phenotype 9:7 Sweet pea flowers

Answer 26

Complementarity

Question 27

Homozygous recessive of one gene masks both alleles of another 9:3:4 Labrador retriever coat color

Answer 27

Recessive Epistasis

Question 28

Dominant allele of one gene masks the effects of both alleles of another gene 12:3:1 Summer squash color

Answer 28

Dominant Epistasis 1

Question 29

Dominant allele of one gene hides effects of dominant allele of other gene 13:3 Chicken feathers

Answer 29

Dominant Epistasis 2

Question 30

Only one dominant allele of either of 2 genes is necessary to produce a phenotype 15:1 Maize leaves

Answer 30

Redundancy

Question 31

A mutation at any one of a number of genes can give rise to the same phenotype, deafness

Answer 31

Heterogeneous trait

Question 32

When what appears to be an identical recessive phenotype arises in two separate breeding lines. Are mutations in the same gene responsible for the phenotype in both lines? If offspring receiving the two mutations (one from each parent) expresses the wild type complementation has occurred

Answer 32

Complementation test

Question 33

Dominant allele which also acts as a recessive lethal in mice

Answer 33

Agouti

Question 34

OAC, case of complementation, aaBB x AAbb

Answer 34

Ocular cutaneous albanism

Question 35

How members of a population with a particular genotype show the expected phenotype, %, occourance

Answer 35

Penetrance

Question 36

Degree or intensity with which a particular genotype is expressed in a phenotype, can be variable (retinoblastoma) or unvarying (like peas) seriousness of disease

Answer 36

Expressivity

Question 37

Alter the Phenotypes produced by the alleles of other genes, subtle, T mutation in mice

Answer 37

Modifier genes

Question 38

Environment acting on phenotype, temperature sensitive enzyme

Answer 38

Siamese variant

Question 39

Temp sensitive shibire gene in fruit flies, lethal only under certain conditions

Answer 39

Conditional lethal

Question 40

Conditions under which an organism remains viable

Answer 40

Permissive conditions

Question 41

Conditions that are lethal

Answer 41

Restrictive conditions

Question 42

A change in phenotype similar to that of mutant genes, not heritable, thalidomide, pku

Answer 42

Phenocopy

Question 43

Discrete trait like pea plant height

Answer 43

Discontinuous trait

Question 44

Continuous phenotypic variation, skin color, height in humans, polygenic

Answer 44

Continuous trait

Question 45

Population in which individuals differ in alleles of many genes

Answer 45

Outbred population

Question 46

Homozygotes may survive beyond birth but die before passing on a disease allele (Tay Sachs)

Answer 46

Delayed lethality

Question 47

Homozygote may pass on recessive lethal alleles (cancer)

Answer 47

Late-onset diseases

Question 48

All ____________ early lethal mutant alleles must be new mutations.

Answer 48

Dominant, they have never been passed on.

Question 49

Plieotropy, recessive lethality, different dominance relations. Hb alpha (wild type) and Hb beta genes. 400 mutants Hb beta s causes sickle-cell.

Answer 49

Sickle-cell anemia

Question 50

Hb beta a and Hb beta s show dominance recessive (shape), codominance (shape at high altitudes), and incomplete dominance (concentration of cells), and dominance recessive (susceptiblity to malaria).

Answer 50

relationships in sickle cell-anemia

Question 51

The allele that does the masking is ___________ to the gene that is being masked (the hypostatic gene).

Answer 51

Epistatic

Question 52

Gene _____ determine black and chocolate coat color in labs.

Answer 52

B alleles

Question 53

Recessive allele __ of __ gene is Epistatic to ___ and determines yellow coat color In labs.

Answer 53

e, E, B

Question 54

9:3:4 ratio in the ____ indicates __________ Epistasis.

Answer 54

F2, recessive

Question 55

_______ ________ in humans causes rare Bombay blood type.

Answer 55

Recessive Epistasis

Question 56

H, H__

Answer 56

Gene for substance _____ is epistatic to the ABO gene. All type A, type AB, type B, and type O are ____.