Exam 3 Part 1

Question 1

Discrete traits

Answer 1

no severity/degree

very distinct phenotypes

Question 2

discrete phenotypes

Answer 2

clearly defined by 1 or a few genes

Question 3

quantitative traits

Answer 3

measurable in numeric terms
-quantifyable
have continuous variation

Question 4

continuous variation

Answer 4

phenotypes are distributed along a continuum; sereis of intermediate phenotypes that fall between
2 extremes

Question 5

quantitative traits controlled by…

Answer 5

multiple genes and environmental factors

Question 6

quantitative genetics

Answer 6

studyof inheritance of quantitative traits

Question 7

contributing alleles

Answer 7

additive alleles.
number of copies of these alleles influence the degree of severity of a trait
Alleles A and B result in red pigment, a and b do not product pigment

Question 8

One gene variates

Answer 8

F2

1:2:1

Question 9

two gene variation

Answer 9

F2

1:4:6:1

Question 10

three gene variation

Answer 10

F2

1:6:15:20:15:6:1

Question 11

distribution

Answer 11

summary of continuous phenotypic variance for a group

Question 12

population

Answer 12

all individuals

Question 13

sample

Answer 13

representatitive subset of population

Question 14

sample should be…

Answer 14

randomly selected - unbiased

large enough

Question 15

environmental effects on quantitative traits

Answer 15

causes variation within each genotypic class 
blurred lines between phenotypic classes

Question 16

how environmental effects are studied

Answer 16

with modern genotyping methods such as PCR

Question 17

VG

Answer 17

genotypic variance

contribution of alleleic differences at multiple genes

Question 18

VE

Answer 18

environmental variance

contributions from nongenetic sources

Question 19

VgxVe

Answer 19

genotype by environment variance

Question 20

Vp

Answer 20

phenotypic variance

Vp=Vg+Ve=(VgxVe)

Question 21

heritiability

Answer 21

how much of the phenotypic differences are due to genetic factors
0, 0.5, 1

Question 22

0 heritiability

Answer 22

none of the variation in phenotype bt individuals results from genetic differences

Question 23

0.5 heritability

Answer 23

half of the phenotypic variation is due to genetic differences between individuals and half is due to environment

Question 24

1 heritability

Answer 24

all variation is genetically based

Question 25

Quantitative Trait Loci

Answer 25

QTL

loci that play a role/influence quantitative traits

Question 26

genetic architecture of a trait

Answer 26

all QTL and how they interact

use molecular tools and statistics to link quantitative phenotypes and QTLs