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Flashcards in Exam 3 Part 1 Deck (26)
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1

Discrete traits

no severity/degree
very distinct phenotypes

2

discrete phenotypes

clearly defined by 1 or a few genes

3

quantitative traits

measurable in numeric terms
-quantifyable
have continuous variation

4

continuous variation

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

5

quantitative traits controlled by...

multiple genes and environmental factors

6

quantitative genetics

studyof inheritance of quantitative traits

7

contributing alleles

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

8

One gene variates

F2
1:2:1

9

two gene variation

F2
1:4:6:1

10

three gene variation

F2
1:6:15:20:15:6:1

11

distribution

summary of continuous phenotypic variance for a group

12

population

all individuals

13

sample

representatitive subset of population

14

sample should be...

randomly selected - unbiased
large enough

15

environmental effects on quantitative traits

causes variation within each genotypic class
blurred lines between phenotypic classes

16

how environmental effects are studied

with modern genotyping methods such as PCR

17

VG

genotypic variance
contribution of alleleic differences at multiple genes

18

VE

environmental variance
contributions from nongenetic sources

19

VgxVe

genotype by environment variance

20

Vp

phenotypic variance
Vp=Vg+Ve=(VgxVe)

21

heritiability

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

22

0 heritiability

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

23

0.5 heritability

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

24

1 heritability

all variation is genetically based

25

Quantitative Trait Loci

QTL
loci that play a role/influence quantitative traits

26

genetic architecture of a trait

all QTL and how they interact
use molecular tools and statistics to link quantitative phenotypes and QTLs