population and evolution

Question 1

Gene pool

Answer 1

all alleles of all genes of all individuals in a species

Question 2

allellic frequency

Answer 2

the number of times an allele appears in a population

Question 3

wardy weinburg

Answer 3

is a maths equation that shows allele frequency of a specific gene

Question 4

what does the hardy Weinburg equation assume?

Answer 4

no mutation occur 
no migration occurs 
no selection
large population 
random mating
isolated population

Question 5

variation in phenotype

Answer 5

differences in physical characteristics caused by genetic and environmental reasons

Question 6

mutations

Answer 6

These sudden changes to genes and chromosomes

may, or may not, be passed on to the next generation. Mutations are a main source of variation.

Question 7

meiosis

Answer 7

random segregation

crossing over of alleles

Question 8

fertilisation

Answer 8

random

Question 9

environment factors for variation in phenotype

Answer 9

Environmental influences include
climatic conditions (e.g., temperature. rainfall. and sunlight), soil
conditions, pH. and food availability.

Question 10

continuous features are shown in

Answer 10

normal curves

Question 11

The environmental factors that limit the population of a species are called

Answer 11

selection pressures

Question 12

the process that affects selections

Answer 12

organisms produce more offspring than can be supported by the
the available supply of food, light, space, etc.
• there is a genetic variation within the populations of all species.
• a variety of phenotypes that selection operates against.

Question 13

overpopulation

Answer 13

increases intraspecific competition

individuals best fitted outcompete and produces

Question 14

stabilising selection

Answer 14

preserves the average phenotype (phenotypes
around the mean) of a population by favouring average individuals,

selection against the extreme phenotypes

Question 15

directional selection

Answer 15

changes the phenotypes of a population by
favouring phenotypes that vary in one direction from the mean of the population.

selection for one extreme phenotype

Question 16

disruptive selection

Answer 16

favours individuals with extreme phenotypes

rather than those with phenotypes around the mean of the population.

Question 17

what affects allele frequency

Answer 17

selection

Question 18

speciation

Answer 18

the process where a new species develops from an existing species that have a common ancestor that could reproduce to have fertile young

Question 19

speciation process

Answer 19

one or more populations of a species become separated

different mutations will occur in a population

populations have different selections pressures

natural selection-

leads to different allelic frequency

Question 20

genetic drift

Answer 20

this happens in small populations where genetic variation is small
as there is a small number of alleles there is not an equal ratio for them to be passed on.