State a function of each of the following parts of the human brain.

(i)  Cerebellum

(ii)  Hypothalamus

Identify the two most closely related organisms.

Identify the species to which the Bonobo is most distantly related.

Describe one type of barrier that may exist between gene pools.

(i)  (coordinates) unconscious motor functions/balance and movement

(ii)  (maintains) homeostasis/thermoregulation/appetite/thirst / coordinates endocrine systems / secretes hormones/regulating factors

(common) chimpanzee and bonobo

gibbon

named barrier;
description of its action;
results in terms of gene pools;
e.g.:
behavioural barrier;
different populations mate at different times of year thus preventing interbreeding;
allele frequencies become different in the two gene pools/separates gene pools / sympatric speciation;

The vast majority of candidates provided correct answers.

This part presented a cladogram of larger primates and the two subparts were interpreted correctly by the vast majority of candidates.

This part presented a cladogram of larger primates and the two subparts were interpreted correctly by the vast majority of candidates.

This part required candidates to name a barrier that may exist between gene pools and describe its action and the results in terms of gene pools. Mixed results were obtained here, although many candidates gained all the marks. Some candidates confused between types of barrier and types of evolution (e.g. geographic vs allopatric), were vague about its action and could not relate to gene pools.