Chapter 13 - Population Genetics

Question 1

variations in population can be

Answer 1

structural
biochemical
physiological 
behavioural 
developmental
geographic

Question 2

cline

Answer 2

gradual change in a trait in members of a population across its geographic range

Question 3

monomorphic

Answer 3

no variation in a population

all members identical with regards to a particular phenotypic trait

Question 4

polymorphic

Answer 4

two or more variations of a particular trait in a population

Question 5

causes of variation

Answer 5

environmental factors

genetic factors

Question 6

gene pool

Answer 6

the sum total of all genes present in a population at any one time
allele frequencies

Question 7

population

Answer 7

the total number of one species inhabiting a particular geographical area

Question 8

allele frequency

Answer 8

frequencies of a particular allele in a population

no. alleles from dominant trait / total no. alleles

Question 9

freq A + freq a =

Answer 9

1

Question 10

fixed allele

Answer 10

when the frequency of one allele is equal to 1

all organisms are homozygous

Question 11

gene flow

Answer 11

movement of genes into and out of a population due to migration

Question 12

immigration

Answer 12

gene flow into a population

Question 13

emigration

Answer 13

gene flow out of a population

Question 14

what does migration cause

Answer 14

new alleles in population
change to gene pool
more genetic diversity

Question 15

genetic drift

Answer 15

unpredictable changes in allele frequencies from one generation to the next due to chance events
direction of change is random

Question 16

bottleneck effect

Answer 16

chance effects on allele frequencies in a population as a result of a major reduction in population size
survivors unrepresentative of original sample

Question 17

founder effect

Answer 17

unrepresentative sample of a population leave to colonise a new region

Question 18

fitness / fitness value

Answer 18

the value of their survival due to their selective advantages or disadvantages

Question 19

selecting agent

Answer 19

an environmental factor that causes differences to occur between phenotypes in a population

Question 20

selective advantage

Answer 20

higher genetic fitness of phenotype compared to others in population

Question 21

natural selection

Answer 21

the action of selecting agents in populations in the wild
no human intervention
over successive generations

Question 22

differential reproduction

Answer 22

when 1 phenotype produces more viable offspring than the other and so makes a greater contribution to the gene pool of the next generation

Question 23

theory of natural selection

charles darwin

Answer 23

variation
struggle for survival
selective advantage
inheritance

Question 24

artificial selection

Answer 24

breeding from individuals with the most desirable phenotypes
select parents for offspring
change more rapid and intense

Question 25

species

Answer 25

a group of organisms that can breed to produce fertile offspring