Topic 11

Question 1

Genetic structure

Answer 1

description of genetic variation among individuals within a population

Question 2

Gene flow

Answer 2

exchange of genetic material among populations resulting from dispersal

Question 3

Genetic variation depends on number and variability of..

Answer 3

selection pressures acting on individuals with in a population

Question 4

Low variation

Answer 4

few selection pressure w low variability

Question 5

High variation

Answer 5

many selection pressures w high variability

Question 6

To quantify the level of genetic variation in a population

Answer 6

-level of heterozygosity. more alleles in the gene pool more possible combinations of alleles is higher genetic variation

Question 7

General pattern

Answer 7

smaller populations ten to have lower genetic diversity (variation) than larger population

Question 8

2 mechanisms aperating to decrease geneitc diversity over time

Answer 8

• genetic drift

- interbreeding

Question 9

Genetic drift =

Answer 9

random changes in allele frequencies within a population due to chance

Question 10

Random

Answer 10

no discrimination between (or selection of) individuals with favourable or unfavourable traits

Question 11

Chance

Answer 11

unpredictable change in environmental conditions

Question 12

Genetic drift occurs in..

Answer 12

all populations and is a mechanisms of evolution

Question 13

In small populations genetic drift..

Answer 13

occurs at a faster rate and is more likely to result in loss of an allele

Question 14

Inbreeding

Answer 14

mating between relatives

Question 15

In small populations the choice of mates ..

Answer 15

can be limited resulting in increased probability of mating w relatives

Question 16

Interbreeding tends to..

Answer 16

increase homozygosity and decrease heterozygosity (related indiv. share similar traits

Question 17

Eventually populations can become exclusively homozygous and if rare recessive genes are harmful homozygosity for recessive genes can result in..

Answer 17

reduces fitness and increase mortality

Question 18

Interbreeding depression

Answer 18

loss of vitality and increased incidence of disease due to the expression of deleterious recessive alleles when genetic diversity decrease

Question 19

Black robin in New Zealand

Answer 19

populations reduced significantly. 1980 5 individuals were remaining but one female. more 250 individuals but lower fitness 30% hatching failure. because good proportion of sperm are abnormal (non motile) so many eggs are never fertilized

Question 20

2 key concepts needed to maintain genetic diversity

Answer 20

• effective population size

- minimum viable population

Question 21

Effective population size

Answer 21

subset of males and females within a poulation that successfully breed. defines the number of indiv. passing genes to successive generations

Question 22

Minimum viable population

Answer 22

number of individuals necessary to ensure the long term survival of a species.

Question 23

Whatys crtitcal in conservation biology

Answer 23

-minimum viable populations. allows us to calculate how large a population of a particular species should be to assure its long term survival