2.2 evolution

Question 1

what are three types of symbiotic interactions?

Answer 1

mutualism (+/+), commensalism (+/0), parasitism (+/-)

Question 2

in what kind of interaction does co-evolution usually occur?

Answer 2

A symbiotic interaction

Question 3

in co-evolution, how does a change in the traits of one species affect the other species?

Answer 3

it acts as a selection pressure

Question 4

what is co-evolution?

Answer 4

change in the genetic composition of one species (or group) in response to a genetic change in the other

Question 5

how is relative fitness calculated?

Answer 5

number of surviving offspring per individual of a particular genotype/number of surviving offspring per individual of the most successful genotype

Question 6

what is relative fitness?

Answer 6

the ratio of surviving offspring of one genotype compared with the most successful genotype

Question 7

what does an absolute fitness of 1 mean?

Answer 7

the number of individuals of that genotype is stable

Question 8

what does an absolute fitness of <1 mean?

Answer 8

there is a decrease in individuals of that genotype

Question 9

what does >1 mean?

Answer 9

there is an increase in individuals of that genotype

Question 10

what is absolute fitness?

Answer 10

the ratio that compares the frequency of a particular genotype from one generation to the next

Question 11

what is fitness?

Answer 11

a term used to measure an individual’s ability to be successful at surviving and reproducing, and refers to the genetic contribution made to the next generation

Question 12

what does q2 represent?

Answer 12

frequency of homozygous recessive genotype

Question 13

what dos 2pq represent?

Answer 13

frequency of heterozygous genotype

Question 14

what does p2 represent?

Answer 14

frequency of homozygous dominant genotype

Question 15

what does q represent?

Answer 15

frequency of recessive allele

Question 16

what does p represent?

Answer 16

frequency of dominant allele

Question 17

what is the equation used to calculate allele, genotype and phenotype frequencies in a population?

Answer 17

p2 + 2pq + q2 = 1

Question 18

what can the HW principle be used to determine?

Answer 18

whether a change in allele frequency is occurring in a population over time

Question 19

what does the Hardy-Weinberg principle state?

Answer 19

in the absence of evolutionary influences, allele and gene frequencies in a population will remain constant over generations

Question 20

name some abiotic selection pressures

Answer 20

• change of temperature
• light
• himidity
• pH and salinity

Question 21

name some biotic selection pressures

Answer 21

• competition<div>
• predation</div><div>
• disease</div><div>
• parasitism</div>

Question 22

<p>what are selection pressures?</p>

Answer 22

the environmental factors that influence which individuals in a population pass on their alleles

Question 23

what can cause the rate of evolution to be rapid?

Answer 23

when selection pressures are high

Question 24

how does natural selection affect the population?

Answer 24

non-random increase in the frequency of advantageous alleles and the non-random decrease in the frequency of deleterious alleles.

Question 25

how does sexual selection affect the population?

Answer 25

inbreeding or selection of mates for specific phenotypes will reduce heterozygosity.

Question 26

how do mutations affect the population?

Answer 26

increases or decreases allele frequencies, and may introduce new alleleforms

Question 27

what is gene flow?

Answer 27

movement of alleles due to immigration and emigration of individuals between populations

Question 28

what are some male rivalry strategies to gain access to females?

Answer 28

- acquiring and defending territories and harems - direct conflict - superior size and weaponry - alpha male approach

Question 29

which aspects of a male play a role in female choice and why?

Answer 29

male resources, appearance and courtship as it shows the levels of male fitness

Question 30

what does sexual selection refer to?

Answer 30

it is females who retain primary control over reproduction

Question 31

how do behavioural sex differences affect the organism?

Answer 31

they can decrease its chance of survival as it is more visible to predators, but allow for greater success in mating

Question 32

what are common examples of behavioural sex differences?

Answer 32

- pronounced coloration

- increased size

- striking adomments

- elaborate courtship behaviours

Question 33

what is the clearest sexual dimorphism amongst vertebrates?

Answer 33

gamete size

Question 34

describe the process of natural selection

Answer 34

- populations produce more offspring than the environment can support - individuals with variations that are better suited to the environment survive longer and reproduce more - meaning that favourable alleles are passed on to future generations

Question 35

how do founder effects alter a gene pool?

Answer 35

certain alleles may be under/over-represented, causing allele frequencies to change

Question 36

what are founder effects caused by?

Answer 36

the isolation of a few members of a population that are not representative of the original gene pool

Question 37

when do bottleneck effects occur?

Answer 37

when a population size is reduced for at least one generation

Question 38

how can genetic drift reduce genetic diversity?

Answer 38

it causes the random loss of rare alleles

Question 39

what kind of population does genetic drift have a greater impact on and why?

Answer 39

small, isolated populations - alleles are more likely to be lost from the gene pool

Question 40

what is genetic drift caused by?

Answer 40

chance events or unpredictable fluctuations

Question 41

what is genetic drift?

Answer 41

the random change in how frequently a particular allele occurs within a population

Question 42

what is a non-random process in evolution?

Answer 42

natural selection, sexual selection

Question 43

what is a random process in evolution?

Answer 43

genetic drift

Question 44

what is evolution?

Answer 44

the change over time in the proportion of individuals in a population differing in character traits