Genetic Diversity & Adaptation

Question 1

what is genetic diversity?

Answer 1

the number of different alleles of genes in a population

Question 2

what is a gene pool?

Answer 2

the number of different alleles of a gene there is in a population

Question 3

what is a gene?

Answer 3

a base sequence of DNA which codes for a polypeptide or a functional RNA

Question 4

what is allele frequency?

Answer 4

number of times an allele occurs in a population

Question 5

what 2 things increase genetic diversity within a population?

Answer 5

a random mutation in DNA
different alleles being introduced into the population from another population OF THE SAME SPECIES

Question 6

what is a mutation?

Answer 6

a change in the base sequence of DNA

Question 7

what are the 2 ways that decreases the genetic diversity in a population?

Answer 7

when a few organisms start a new colony
when an event causes a big reduction in a population

Question 8

what is natural selection?
(MASSRIFT)

Answer 8

a random MUTATION results in a new advantageous ALLELE which makes them more likely to SURVIVE and REPRODUCE. their offspring will INHERIT the advantageous alleles and over many generations the allele FREQUENCY will increase. this is stabilising/directional TYPE of selection

Question 9

what is evolution?

Answer 9

the gradual change in species over time

Question 10

what are the 2 key factors in evolution?

Answer 10

adaptation
selection

Question 11

what does natural selection cause?

Answer 11

organisms becoming better adapted to their environment

Question 12

what are adaptions?

Answer 12

features which help an organism to survive in their environment

Question 13

what are the 3 types of adaption?

Answer 13

behavioural
anatomical
physiological

Question 14

what is a behavioural adaption?

Answer 14

an organism change their behaviour in order to survive

Question 15

what is an example of a behvioural adaption?

Answer 15

possums “play dead” when they sense danger or feel threatened

Question 16

what is a physiological adaption?

Answer 16

a chemical process inside an organism’s body which increases their chance of survival

Question 17

what is an example of a physiological adaption?

Answer 17

brown bears lower their metabolism over winter when hibernating

Question 18

what is an anatomical adaption?

Answer 18

a structural feature of an organism which increases their chance of survival

Question 19

what is an example of an anatomical adaption?

Answer 19

whales have a large layer of blubber which allows them to hunt in cold seas where their food is

Question 20

what are the 2 types of selection?

Answer 20

stabilising
directional

Question 21

when does stabilising selection occur?

Answer 21

in populations where the environment is stable

Question 22

what does stabilising selection select?

Answer 22

the average

Question 23

what does stabilising selection select against?

Answer 23

the extreme phenotypes

Question 24

what does stabilising selection reduce?
(4 points)

Answer 24

variability
range
opportunity for evolutionary change
range of possible characteristics

Question 25

what is an example of stabilising selection?

Answer 25

birth mass in humans:
very large or very small babies have a higher neonatal mortality rate than medium babies

Question 26

where is the selection pressure during directional selection?

Answer 26

at one end of the distribution

Question 27

what does directional selection favour?

Answer 27

one extreme

Question 28

what does directional selection do to the distribution?

Answer 28

skews it in one direction forming a new mode

Question 29

what does directional selection do?

Answer 29

increases the evolutionary change

Question 30

what is an example of directional selection?

Answer 30

antibiotic resistance n bacteria

Question 31

what happens to the allele frequency in directional selection?

Answer 31

the allele frequency increases gradually over time

Question 32

what happens to the allele frequency in stabilising selection?

Answer 32

the allele frequency reduces over time