CH 223

Question 1

What is the smallest unit evolution operates on?

Answer 1

population

Question 2

What is the word for evolution on the level of populations?

Answer 2

microevolution

Question 3

genetic variation

Answer 3

differences in gene composition within a gene pool

Question 4

gene variability

Answer 4

average percentage of loci that are heterozygous

Question 5

nucleotide variability

Answer 5

variation at nucleotide level

Question 6

introns

Answer 6

noncoding segments of DNA

Question 7

exons

Answer 7

portions of DNA that do code

Question 8

Mutation

Answer 8

random change in the nucleotide sequence of an organisms DNA

Question 9

neutral variation

Answer 9

differences in the sequence of DNA that do not interfere with the fitness of the organism

Question 10

HW eq: allele freqs

Answer 10

p+q=1

Question 11

hw eq: genotype freqs

Answer 11

p^2+2pq+q^2=1

Question 12

5 conditions for hw

Answer 12

1. no mutations
2. extremely large pop
3. no gene flow
4. random mating
5. no natural selection

Question 13

Chi-square eq

Answer 13

x^2=£[O-E)^2/E]

Question 14

Mutation

Answer 14

Changes in dna cause new genes and alleles to arise

Question 15

Gene flow

Answer 15

Movement of alleles among pops

Question 16

Genetic drift

Answer 16

Random changes in allele freqs

Question 17

Founder effect

Answer 17

A few indivs isolated from source pop; allele freqs can vary

Question 18

Bottleneck effect

Answer 18

Sudden drop in pop due to enviro catastrophe

Question 19

Non random mating

Answer 19

Indivs with certain genotypes mate more or less than expected my chance

Question 20

Intrasexual selection

Answer 20

b/w same sex

Question 21

Intersexual selection

Answer 21

Diff sexes

Question 22

Sexual selection

Answer 22

Natural selection for mating success

Question 23

Natural selection

Answer 23

Unequal success in repro leads to certain alleles being passed on in greater proportions

Question 24

Directional selection

Answer 24

Favors one end of phenotype range

Question 25

Disruptional selection

Answer 25

Favors both extremes of phenotype range

Question 26

Stabilizing selection

Answer 26

Favors intermediate phenotypes

Question 27

True or false: genetic drift has a more sizable impact on small populations

Answer 27

True

Question 28

Diploidy

Answer 28

Maintains variation via hidden recessive alleles; heterozygotes remain carriers

Question 29

Balancing selection

Answer 29

2+ phenotypic forms remain stable

Question 30

Heterozygous advantage

Answer 30

Heterozygotes are fitter than homozygotes ie. sickle cell

Question 31

Frequency dependent

Answer 31

Fitness declines if phenotype is too common: unique is ideal

Question 32

Neutral variation

Answer 32

Gen variation that appears to confer no selective advantage or disadvantage

Question 33

Does natural selection make perfect organisms?

Answer 33

No. . . - selection can only act on existing variations - evolution is limited by historical constraints -adaptations are often compromises