Natural selection

Question 1

what is ecology ?

Answer 1

the study of living things within their environment

Question 2

what is an ecosystem ?

Answer 2

a community of organisms and their surroundings
- basic unit of ecology
- numerous habitats - place where an organism lives

Question 3

what is a niche ?

Answer 3

interacts within its environment
- it is a producer so produces food for other organisms

Question 4

ecological niche - define

Answer 4

not only where a species lives but all of its activities its predators and how it interacts with the non living environment around it

Question 5

what is adaptation ?

Answer 5

process by which an organisms becomes fitted to its environment

Question 6

what are the three types of adaptations ?

Answer 6

• biological
• physiological
• anatomical

Question 7

what is physiological adaptation ?

Answer 7

changes to the metabolism of the organism which are advantageous to survival in their particular habitat

Question 8

what is anatomical adaptation ?

Answer 8

involves how body structures adapt to regulate heat loss

Question 9

what is behavioural adaptation ?

Answer 9

these the actions by the organisms which help them to survive and reproduce

Question 10

exotherms - define

Answer 10

cannot regulate their body temperature internally

Question 11

what is evolution ?

Answer 11

the development of new types of living organism from pre existing types by the accumulation of genetic differences over a long period of time

Question 12

when did Charles Darwin put forwards his ideas ?

Answer 12

1859

Question 13

how do you prevent fossils from being formed or found
?

Answer 13

• scavengers, bacterial action - decompose and dismember dead plants and animals
• stopping fossils being formed: never found, recovered or interpreted

Question 14

dating fossils, carbon dating

Answer 14

present in CO2
- C14 taken in by plants
- eaten by animals
- has a half life about 5700 years

Question 15

what is proteomics ?

Answer 15

the study of proteins coded for specific genes

Question 16

gene pool - define

Answer 16

the total variety of genes and alleles present in a sexually reproducing population

Question 17

speciation - define

Answer 17

is the process by which one species evolves into a new species

Question 18

how is speciation more likely to occur ?

Answer 18

• part of the population is isolated in some way - gene pool isolated population changes

Question 19

what is allopatric speciation ?

Answer 19

two populations are totally separated from each other by a physical barrier - prevents interbreeding

Question 20

what does geographical isolation lead to ?

Answer 20

allopatric isolation

Question 21

what is geographic isolation ?

Answer 21

before isolation - share a common gene pool
after isolation - natural selection, mutations and random genetic drift occur in both populations

Question 22

what is sympatric speciation ?

Answer 22

two populations can mix freely in the same area but some individuals accumulate changes in their gene pools - no physical barrier

Question 23

what occurs in reproductive isolation?

Answer 23

occurs when changes are brought about by natural selection

Question 24

what is stabilising selection ?

Answer 24

occurs when conditions are favourable and not changing
- maintains the favourable characteristics make species successful - eliminates alleles that are harmful or useless

Question 25

what is directional selection ?

Answer 25

occurs when environment are changing and there is clear advantage of the population changing in one direction

Question 26

how does evolution relate to bacterial antibiotic resistance ?

Answer 26

• bacteria develop random mutations
• survives non resistant killed less competition for nutrients
• evolutionary race

Question 27

evolutionary race

Answer 27

new antibiotics were discovered and were very effective
- ignored evolution resistance
- widespread use meant selective pressures increased along with evolutionary race

Question 28

what was the results of evolutionary race ?

Answer 28

• increased doses needed to treat the same infection
• resistant strains of the infection - new antibiotics was needed