Unit 2:Organisms and evolution KA2.2-evolution

Question 1

define the term evolution

Answer 1

evolution is the change over time of the proportion of individuals in a population differing in one or more traits

Question 2

what can cause evolution to be rapid

Answer 2

selection pressures

Question 3

name the 2 types of selection pressures

Answer 3

biotic and abiotic

Question 4

name some biotic factors

Answer 4

competition, predation, parasitism and disease

Question 5

name some abiotic factors

Answer 5

changes in temperature, light, humidity, pH and salinity

Question 6

what are the 2 types of evolution

Answer 6

random and non-random

Question 7

example of random evolution

Answer 7

genetic drift, examples of this is population bottleneck and the founder effect

Question 8

types of non random selection

Answer 8

natural selection and sexual selection

Question 9

why does variation exist in a species

Answer 9

mutations

Question 10

description of male-male rivalry

Answer 10

large size or weaponry increases access to females through conflict

Question 11

description of female choice

Answer 11

female choice involves females assessing the fitness of males

Question 12

define genetic drift

Answer 12

the ratio of genotypes changing randomly overtime, resulting in some alleles being under or over represented

Question 13

describe population bottleneck

Answer 13

a population bottleneck is an event that drastically reduced the size of a population for at least one generation, leaving a population with a reduced genetic diversity

Question 14

describe the founder effect

Answer 14

founder effect occurs through the isolation of a few members of a population from a larger population

this new gene pool is not representative of the original one

Question 15

the 5 conditions for maintaining the hardy-weinberg principle

Answer 15

-no selection occurring
-no mutation
-no migration
-random mating
-large population

Question 16

define the term fitness

Answer 16

fitness is a measure of the tendency of some organisms to produce more surviving offspring than competing members of the same species

fitness can be describes in absolute or relative terms

Question 17

what does p mean in the hardy weinberg equation

Answer 17

frequency of the dominant allele

Question 18

what does q mean in the hardy weinberg equation

Answer 18

frequency of the recessive allele

Question 19

what does p squared mean in the hardy weinberg equation

Answer 19

frequency of the homozygous dominant genotype

Question 20

what does 2pq mean in the hardy weinberg equation

Answer 20

frequency of the heterozygous genotype

Question 21

what does q squared mean in the hardy weinberg equation

Answer 21

frequency of the homozygous recessive genotype

Question 22

what are the hardy weinberg equations

Answer 22

p+q=1
p squared + 2pq + q squared=1

Question 23

what is absolute fitness

Answer 23

the ratio of frequencies of a particular genotype from one generation to the next

Question 24

what is relative fitness

Answer 24

the ratio of surviving offspring of one genotype compared to other genotypes

Question 25

define the term co-evolution

Answer 25

the process by which 2 or more species evolve in response to selection pressures imposed by each other. A change in the traits of one species acts acts as a selection pressures imposed on the other

Question 26

definition of mutualism

Answer 26

-both organisms in the interaction are interdependent on each other for resources or other services -both organisms gain something from the relationship

Question 27

definition of commensalism

Answer 27

only one of the organisms benefits, but the interaction does not negatively affect the other

Question 28

definition of parasitism

Answer 28

the parasite benefits in terms of energy or nutrients and the host is harmed as a result of the loss of these resources

Question 29

define the term symbiosis

Answer 29

a co-evolved intimate relationship between members of 2 different species

Question 30

what does the red queen hypothesis state

Answer 30

in a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species