Chapter 24: Quantitative Genetics

Question 1

Quantitaive Genetics

Answer 1

genetic analysis of complex characteristics

Question 2

Disconinuous (Qualitative) Traits

Answer 2

possess only a few phenotypes

Question 3

What exhibits only a few, easily distinguishable phenotypes?

Answer 3

discontinuous (qualitative) traits

Question 4

Continuous (Quantitative) traits

Answer 4

characteristics vary along a scale of measurement with many overlapping phenotypes

Question 5

What trait has multiple alleles at multiple alleles at multiple loci?

Answer 5

continous (quantitative) traits

Question 6

What does quantitative refer to?

Answer 6

number of genes involved

Question 7

What trait exhibits a continuous range of phenotypes?

Answer 7

continuous (quantitative) traits

Question 8

Why are relationships between genotype and phenotype complex?

Answer 8

-may be polygenic
-may have environmental influences

Question 9

What is determined by genetic and environmental factors, and can be measured in whole numbers?

Answer 9

meristic characteristics

Question 10

What characteristic is measured by presence or absence?

Answer 10

threshold characteristic

Question 11

What characteristic looks like a mendalian trait?

Answer 11

threshold characteristics

Question 12

What characteristics are susceptible to disease?

Answer 12

threshold characteristics

Question 13

What does polygenic inheritance?

Answer 13

refers to quantitative characteristics controlled by cumulatice effects on many genes

Question 14

What does each polygenic inheritance character still follow (as long as they aren’t linked)?

Answer 14

mendel’s rules

Question 15

What are polygenic inheritance characteristics possibly influenced by?

Answer 15

environmental factors

Question 16

As the number of _____ affecting the trait increases, the number of phenotypic classes ____

Answer 16

loci; increases

Question 17

What is n?

Answer 17

number of loci with a segregating pair of alleles that affect the characteristic

Question 18

What are the chromosomal regions containing genes that influence a quantitative trait?

Answer 18

quantitative trait loci (QTLs)

Question 19

What is accomplished by genome comparison?

Answer 19

mapping QTLs

Question 20

What was relied on before QTLs?

Answer 20

DNA fragmenting patterns

Question 21

What is phenotypic variation due to genetic variability?

Answer 21

heritability

Question 22

Pleiotropy

Answer 22

different phenotypes impacted by the same gene(s)

Question 23

How many traits are needed for pleiotropy?

Answer 23

needs two characteristics to be related