Natural selection

Question 1

fitness

Answer 1

the relative chance that an individual will contribute to the gene pool of the next generation

Question 2

environmental slection pressure

Answer 2

a factor in the environment that impacts an organisms ability to survive and reproduce

Question 3

selective advantage

Answer 3

a phenotype that makes an individual more likely to survive

Question 4

natural selection

Answer 4

the differential survival and reproduction of individuals in a species due to selective advantages and disadvantages conferred by heritable differences their phenotype

Question 5

evolution

Answer 5

the continual process of change in species of living things, key mechanism is natural selection

Question 6

acquireed characteristic

Answer 6

a characteristic that an individual develops during its lifetime

Question 7

are selection pressures allows favoured to one phenotype

Answer 7

no, slective pressures only interact with the organism to provide opposition to its continual survival, some slection pressures will be neutral and no individuals will be favoured

Question 8

examples of selective pressure

Answer 8

co2 concentration, light avaliablity, predators

Question 9

selection agent

Answer 9

the elements of the environment that exerts a selection pressure

Question 10

selection pressure

Answer 10

the environmental factor which causes differential death in members of a species due to phenotypic variation

Question 11

how does natural selection result in evolution

Answer 11

favourable phenotypes are more likely to survive, reproduce and pass on alleles to offspring than those with less favourable phenotypes, over many generations, the genotypes associated with the favourable phenotype will increase in frequency

Question 12

how many steps involved in natural selection

Answer 12

5

Question 13

first step of natural selection

Answer 13

phenotypic variation exists within a population

Question 14

second step of natural selection

Answer 14

selective pressures influence or act on these variations

Question 15

third step of natural selection

Answer 15

organisms with phenotypes that are selected foor will survive more, reproduce more, have moore offspring and pass their alleles to their offspring

Question 16

fourth step of natural selection

Answer 16

less favourable phenotypees will reproduce less

Question 17

fifth step of natural selection

Answer 17

over many generations the selected for trait will increase in frequency

Question 18

words to remember steps in natural selection

Answer 18

1. variation 2. selective pressure 3. favourable reproduce 4. non-favourable dont reproduce 5. frequency over generations

Question 19

4 darwin observattion

Answer 19

1. phenotypic variation exists within a species 2. offspring inherit the trait of their offspring 3. species priduce more offspring than required to replace themselves 4. there is a struggle to survive

Question 20

darwins inferences

Answer 20

individuals whose give them more chance to survive and reproduce, produce more offspring than other individuals
the unequal chance of reproduction will lead to accumulation of favourable traits in the population over generations

Question 21

sexual selection

Answer 21

a form of natural selection in which the selection pressure is the ability to obtain a mate

Question 22

what causes sexual dimorphism

Answer 22

sexual selection

Question 23

why is sexual selection harmful

Answer 23

attributes that give an individual more liklihood to obtain a mate can be a threat to survival (e.g attrcat predators)

Question 24

4 requirements of natural selection

Answer 24

variation, slection pressure, selective advantage and heritability

Question 25

directional selection

Answer 25

when a selection pressure changes to result ina selective advantage for individuals which are less common in a population

Question 26

what does directional selection result in

Answer 26

shift in allele and phenotype frequency

Question 27

what effect does natural selection have on genetic diveristy

Answer 27

reduces it by eliminating alleles that give individuals a selective disadvanteg

Question 28

result of natural selection on allele frequencies

Answer 28

stabilicies them by reducing the frequencies of traits at either extreme range of phenotypes ina populationdis

Question 29

disruptive selection

Answer 29

change in selection pressure that changes the selective advantage to be for either end of a distribution but a disaddvantage for the most common phenotype