TOPIC 7.3-7.4 evolution may lead to speciation + pop in ecosystems

Question 1

sympatric speciation

Answer 1

Not geographically isolated - occurs in same pop.
Reproductive isolation - cannot breed to produce fertile offspring.
Changes in allele freq
Diff alleles passed on
Gene pools remain separate
Disruptive selection

Question 2

allopatric speciation

Answer 2

No interbreeding as geographic isolation
Separate gene pools
Variation due to mutation
Different selection pressures –> Selection for diff adv features. selected organisms survive & reproduce.
Different reproductive success –> Change/inc in allele freq
Adapted organisms breed

Question 3

mark-release-recapture method

Answer 3

Capture sample, mark and release
Method of marking doesnt harm/ make visible to predators.
Leave sufficient time for them to ran distribute before collecting a second sample.

Pop = num in 1st sample × num in 2nd sample divided by num of marked in 2nd sample

Question 4

population of trees in the forest evolved adaptations to the mountain environment.
Use your knowledge of selection to explain how (3)

Answer 4

Variation in org colonisers
Some better (adapted for) survival (in mountains)
Greater reproductive success
Allele freq change

Question 5

succession

Answer 5

Colonisation by pioneer species which change env conditions and make it less hostile for new species eg. provide food for other species
New species colonise once theres a change.
Other species eaten/ outcompeted as sucession continues.
Inc biodiversity to climax community (final/stable community) = abiotic factors constant

Question 6

population

Answer 6

organisms of one species in a habitat

Question 7

community

Answer 7

organisms of all species in a habitat

Question 8

predator prey relationship

Answer 8

prey pop inc = more food for predator so predator pop inc –> more prey killed so prey pop dec
less food for predator = predator pop dec so less prey killed = prey pop inc

Question 9

interspecific competition

Answer 9

diff species

Question 10

intraspecific competition

Answer 10

same species

Question 11

niche

Answer 11

role of species in its habitat. unique (adv) bc less competition for food/resource