b5 - speciation/ classification

Question 1

species

Answer 1

a group of organisms which can interbreed to produce FERTILE offspring

Question 2

a population can evolve into new species - this requires

Answer 2

ISOLATION
- geographical isolation
- reproductive isolation

Question 3

how speciation occurs

Answer 3

• come from common ancestors
• a geographical barrier may form eg river
• species become geographically separate
• competition for resources drives adaptations
• the adaptions make organisms different so cant reproduce
• became so different females dont physically recognise males
• have been apart so long that mating rituals have changed

Question 4

why is it important to have a clear definition of species

Answer 4

some species are dying out - we need to know what a species is to monitor individuals of a species + protect the species

Question 5

peppered moth - evidence of evolution

Answer 5

• were more white moths due to camouflaged in sky
• was a mutant of black moths
• industrial revolution covered trees in soot
• more black moths as they were camouflaged

Question 6

who came up with peppered moth theory + who proved it

Answer 6

James W Tutt
Bernard Kettlewell

Question 7

what are fossils

Answer 7

fossils are remains of the existence of dead organisms
- sometimes traces of organisms are left (TRACE fossils)
- plants / insects sometimes trapped in amber
- trunks of trees found after being buried in mud containing volcanic ash

Question 8

how are fossils formed

Answer 8

• organism dies in water
• covered in sediment
• soft parts decay
• pressure from above turns sediment to rock
• minerals replace body tissues to form rock - hard parts more likely to fossilise

Question 9

why is oxygen not included in the fossilisation process

Answer 9

don’t want decomposers to cause decay
decomposers need O2 for respiration

Question 10

fossils - evidence for evolution

Answer 10

• shows organisms that lived in the past differ from those today (have evolved)

Question 11

why is the fossil record incomplete

Answer 11

• not all organisms fossilise
• are deep underground (uncovered by erosion or plate shift)

Question 12

antibiotics

Answer 12

chemicals that kill bacteria
discovered 1928 - Alexander Flemming

Question 13

antibiotic resistance

Answer 13

• there is variation
• mutation occurs
• few bacteria develops genes which make them resistant to antibiotics
• bacteria are exposed to antibiotic - most die
• more resources for resistant bacteria to multiply
• if the course of antibiotics completes all bacteria is killed
• if course incomplete the resistant bacteria thrive
• antibiotic is no longer effective

Question 14

MRSA superbugs

Answer 14

a bacteria that is resistant to antibiotics

Question 15

resistant rats

Answer 15

• there is variation
• a mutation causes resistance
• non resistant rats die and resistant survive/ reproduce
• pass on resistant gene
• over generations resistance gene increases

Question 16

alfred russel wallace

Answer 16

independently developed the theory of natural selection

Question 17

warning colouration and mimicry - evidence for natural selection

Answer 17

• random mutation of colouring
• those without colouring are eaten so die
• those with colouring survive and reproduce
• pass the colouring allele onto offspring
• over generations freq of colouring allele increases

Question 18

artificial classification

Answer 18

observable characteristics to group organisms according to similarities and differences

Question 19

natural classification

Answer 19

classify organisms according to their evolutionary history and true relationships

Question 20

carl line as

Answer 20

devised natural classification

Question 21

taxonomic system

Answer 21

hierarchy of levels - contains 5 kingdoms

Question 22

5 kingdoms

Answer 22

animals
plants
fungi
protocitista
prokaryotes

Question 23

kingdoms divided further into

Answer 23

kingdom
phylum
class
order
family
genus
species

Question 24

binomial naming

Answer 24

Genus species
eg Homo sapiens
genus has capital - typed in italics - underline if handwritten

Question 25

evolutionary trees

Answer 25

represent natural classification and evolution from a common ancestor

Question 26

evidence for natural classification

Answer 26

DNA sequencing protein analysis

Question 27

new top level

Answer 27

domain - 3 domains (due to advancement of molecular analysis)

Question 28

convergent evolution

Answer 28

independent evolution of similar features in different species