Gene Interactions Part 2

Question 1

most ___ reflect the action of many genes that act
sequentially or jointly, and the phenotype can be affected
by alleles that lack complete dominance and the
environment.

Answer 1

phenotypes

Question 2

is when a characteristic can change gradually, such as a person’s height or weight

Answer 2

continuous variation

Question 3

Crosses between true-breeding strains
can produce ___ with phenotypes
different from both parents

Answer 3

hybrids

Question 4

dominance that . Looks like neither parent

Answer 4

incomplete dominance

Question 5

dominance that Looks like both parents

Answer 5

codominance

Question 6

the phenotype of the
heterozygous hybrid is usually an
intermediate between the
homozygous parents.

Answer 6

incomplete dominance

Question 7

segregation of both phenotype and genotype of incomplete dominance is

Answer 7

1:2:1

Question 8

Alleles contribute different
amounts of functional ____ in incomplete dominance;
total amount determines
phenotypе.

Answer 8

protein

Question 9

Both alternative traits can be visualized in the F1.

Example: spotted lentil plant crossed to a dotted lentil plant.

F1 hybrids look like both parents.

Answer 9

codominance

Question 10

is when both alternative traits are expressed in the
F1 of a cross of two pure breeding parents.

Answer 10

codominance

Question 11

An equal expression of both alleles

Answer 11

codominance

Question 12

example of co dominance

Answer 12

roan coat in cattle

Question 13

Some alleles are neither dominant nor
recessive, and many traits are controlled by
multiple alleles or multiple genes.

t/f

Answer 13

true

Question 14

The expression of a trait involves more than two
alleles

Answer 14

multiple alleles

Question 15

example of multiple alleles expressing one trait

Answer 15

ABO blood group

Question 16

• When heterozygote exceeds the
  phenotypic measurements of the
  homozygous parents

Answer 16

overdominance

Question 17

Considering the position of the homozygous dominant
and recessive parents in the figure below, indicate the
location of the heterozygote if the following dominance
relationships are observed

A) Co-dominance

Answer 17

AA (homozygous dominant) –
Aa (heterozygote, co-dominant) – aa (homozygous recessive)

Question 18

B) Complete dominance

Considering the position of the homozygous dominant
and recessive parents in the figure below, indicate the
location of the heterozygote if the following dominance
relationships are observed

Answer 18

AA (homozygous dominant) –
Aa (heterozygote, complete dominance) –
aa (homozygous recessive)

Question 19

C) Over dominance

Considering the position of the homozygous dominant
and recessive parents in the figure below, indicate the
location of the heterozygote if the following dominance
relationships are observed

Answer 19

AA (homozygous dominant) –
Aa (heterozygote, overdominance) – aa (homozygous recessive)

Question 20

D) Incomplete dominance
Considering the position of the homozygous dominant
and recessive parents in the figure below, indicate the
location of the heterozygote if the following dominance
relationships are observed

Answer 20

AA (homozygous dominant) –
Aa (heterozygote, incomplete dominance) –
aa (homozygous recessive)

Question 21

The product of both alleles (A and a) are expressed
hence it is in between the AA and aa

Answer 21

co-dominance

Question 22

The presence of a dominant allele in the Aa
would mean expressing the dominant trait.

Answer 22

complete dominance

Question 23

The Aa could exceed either AA or aa.

Answer 23

overdominance

Question 24

– The Aa is intermediate.

Answer 24

incomplete dominance

Question 25

Genes of the same cells are located on the same nucleus

Answer 25

non-allelic interaction or gene interaction

Question 26

Considers the possibility that an allele of a gene could interact with or alter the expression of the allele of another gene

Answer 26

non allelic interaction

Question 27

*2 genes 1 phenotype

Answer 27

additive gene action

Question 28

___ in genetics refers to a phenomenon where two different mutations in the genome that individually cause a mutant phenotype, when combined in a heterozygote, result in a wild-type (normal) phenotype. This typically occurs when the mutations are in different genes, and each gene provides what the other lacks, thereby "complementing" each other.

Answer 28

complementation

Question 29

* There is complete dominance in both gene pairs. New phenotypes are formed from the interaction between dominant genes and interaction between recessive genes.

Answer 29

novel phenotype

Question 30

One gene's allele masks the phenotype of the other gene's alleles.

Answer 30

epistasis

Question 31

Four genotypic classes produce fewer than four phenotypes.

Answer 31

epistasis

Question 32

different types of epistasis

Answer 32

recessive epistasis dominant epistasis

Question 33

when the recessive allele of one gene masks the effects of either allele of the second gene.

Answer 33

recessive epistasis

Question 34

when the dominant allele of one gene masks the effects of either allele of the second gene

Answer 34

dominant epistasis

Question 35

Appears like incomplete dominance because some of the progeny look like neither parent, but the ratio is wrong.

Answer 35

recessive epistasis

Question 36

a recessive mutation in one gene masks the phenotypic effects of another

Answer 36

recessive epistasis

Question 37

You can tell this genotype is caused by more than one gene because there are 4 phenotypes not 3 in F2 (9:3:3:1)

Answer 37

2 genes 1 phenotype (additive gene action)

Question 38

one good copy of each gene is needed for expression of the final phenotype (9:7 ratio)

Answer 38

complementary gene action

Question 39

one gene can mask the effect of another gene

Answer 39

epistasis

Question 40

ratio for recessive epistasis

Answer 40

9:3:4

Question 41

ratio of dominant epistasis

Answer 41

12:3:1

Question 42

only double mutant phenotype (15:1 ratio)

Answer 42

duplicate gene

Question 43

Each genotype results in a unique phenotype (ratio of 9:3:3:1)

Answer 43

additive gene interaction

Question 44

At least one dominant allele from each of two genes needed for phenotype (ratio is 9:7)

Answer 44

complementary

Question 45

Homozyous recessive genotype at one locus masks expression at second locus (9:3:4)

Answer 45

recessive epistasis

Question 46

Dominant allele at one locus masks expression at second locus (12:3:1)

Answer 46

dominant epistasis

Question 47

One dominant allele from either of twogenes needed for phenotypе (15:1)

Answer 47

duplicate genes

Question 48

genotype does not necessarily define phenotype, the proportion of individuals with a given phenotype express the phenotype determine the ___

Answer 48

penentrance

Question 49

the degree or intensity with which a particular genotype is expressed in a phenotype in a given individual

Answer 49

epxressivity

Question 50

some both eyes affected, some only one

Answer 50

retinoblastoma

Question 51

One gene may contribute towards several visible characteristics.

Answer 51

pleiotrophy

Question 52

In addition to coat color, a specific allele at this locus also causes lethality.

Answer 52

pleiotropy

Question 53

The phenomenon of a single gene determining multiple distinct traits is known as

Answer 53

pleiotropy

Question 54

examples of pleiotropy

Answer 54

recessive lethal alleles sickle cell syndrome

Question 55

Hereditary congenital deafness in dogs (and cats) is *associated with defects in ___ ___ cells

Answer 55

neural crest

Question 56

Hereditary congenital deafness in dogs (and cats) is *associated with defects in neural crest cells ⚫which are precursors for both

Answer 56

melanocytes

Question 57

⚫required for pigmentation of the coat and eyes

Answer 57

melanocytes

Question 58

they have a subtle, secondary effect which alters the phenotypes produced by the primary genes.

Answer 58

modifier genes

Question 59

The environment may influence the effect of a genotype on the phenotype.

Answer 59

modifying environment

Question 60

The environmental influence of a genotype on the phenotype= phenocopу

Answer 60

modifying environment

Question 61

an individual showing features characteristic of a genotype other than its own, but produced environmentally rather than genetically.

Answer 61

phenocopy

Question 62

The degree to which an allele is expressed may depend on the environment. ➢ Some alleles are heat-sensitive, for example.

Answer 62

environmental effects

Question 63

Traits influenced by such alleles are more sensitive to temperature or light than are the products of other alleles

Answer 63

environmental alleles

Question 64

How many gametes will be produced for the following allele arrangements? shortcut formula is

Answer 64

2n (n=# of heterozygotes)

Question 65

How many gametes will be produced for the following allele arrangements? RrYy

Answer 65

4 gametes

Question 66

How many gametes will be produced for the following allele arrangements? AaBbCCDd

Answer 66

8 gametes

Question 67

How many gametes will be produced for the following allele arrangements? MmNnOoPPQQRrssTtQq

Answer 67

= 64 gametes