evolution.

Question 1

why does a gene with is has a d9ominant allele increase rapidly

Answer 1

allele is dominant so only one allele needed for gene to be expressed

Question 2

symmetric speciation with trees of different flowering times

Answer 2

1. Occurs in the same habitat / environment / population;
2. Mutation/s cause different flowering times;
3. Reproductive separation / isolation
4. Different allele/s passed on / selected
5. Disruptive (natural) selection;
6. Eventually different species cannot (inter)breed to produce
   fertile offspring;

Question 3

allopatric speciation

Answer 3

1.mutation causes variation
2.allopatric speciation geographically isolated
Reproductively isolated
3.different selection pressures
4.different alleles passed on changing allele frequency
5. can no longer reproduce fertile offspring

Question 4

The mark-release-recapture method can be used to estimate the size of a
fish population

Answer 4

Capture/collect sample,
Ensure marking is not harmful
Allow (time for) fish to (randomly) distribute before
collecting a second sample;
(Population =) number in first sample × number in second
sample divided by number of marked fish in second
sample/number recaptured;

Question 5

Succession occurs in natural ecosystems. Describe and explain how
succession occurs.

Answer 5

1. (Colonisation by) pioneer species;
2. Pioneers/species/organisms change the
   environment/habitat/conditions/factors;
3. (Environment becomes) less hostile for other/new species
4. Change/increase in diversity/biodiversity;
5. (To) climax community;

Question 6

Describe how you could estimate the size of a population of sundews in a
small marsh.

Answer 6

use 2 tape measures at 90 degrees
random generator for coordinates
count frequency in quadrat
large sample and mean

Question 7

Explain how using the SIT could reduce transmission of dengue.

Answer 7

intraspecific competition
infertiel males cannot reproduce offspring

Question 8

how can you identify climax community

Answer 8

• stable populations
• same species present