UNIT 1: Key area 7 - evalution

Question 1

what is evolution?

Answer 1

change in organisms over generations
as result of genomic variations

Question 2

natural selection is ?

Answer 2

non random increase in frequency of DNA sequences surviving or not

and non random reduction in frequency of deleterious sequences

Question 3

evolution in stages (summary)

Answer 3

evolution makes to much offspring that the world can support

all species show variation from one another

many offspring die due to struggle for existence before they can make babies

only the fittest and best adapted for eh world and their environment will survive long enough to make more offspring

Question 4

give three examples of slection pressures

Answer 4

predation competition and disease

Question 5

changes in phenotype frequency are a result of what ?

Answer 5

stabilising
directional
or disruptive selection

Question 6

speciation is ….?

Answer 6

new biological species by evolution result of isolation, mutation and selection

Question 7

define species

Answer 7

group of organisms that consist of similar individuals capable of interbreeding or exchanging genes among themselves.

Question 8

what is a isolation barriers ?
why do these exist ?

Answer 8

something stopping sun populations from interaction and sharing genetics

these are essential for speciation to occur

Question 9

stabilising selection

Answer 9

average phenotype

Question 10

directional selection

Answer 10

one extreme of phenotype

Question 11

disruptive selection

Answer 11

two or more phenotypes

Question 12

define horizontal gene transfer

Answer 12

when genera are transferred between individuals in the same generation

Question 13

prokaryotes can…?

Answer 13

exchange genetic material horizontally
making it faster than evolutionary change

Question 14

vertical gene transfer is where …?

Answer 14

genes are transferred from partner to baby in result of sexual or asexual reproduction

Question 15

where is natural selection more rapid ?

Answer 15

in prokaryotes

Question 16

when does allopatric barrier occur ?

Answer 16

when gene flow between two or more populations is stopped by a geographic barrier

Question 17

examples of geographical barriers

Answer 17

rivers
mountains
desert

Question 18

sympathetic speciations is ?

Answer 18

when two or more populations live in the snow environment but are still genetically isolated

Question 19

when does sympatric speciation occur ?

Answer 19

result of behavioural and a olivia o barrier

Question 20

examples of ecological barriers

Answer 20

different habitats, breeding areas, or pH

Question 21

behavioural barrier examples

Answer 21

differnt timings, locations or mating