With respect to Pavlov’s experiments with dogs, distinguish between the conditioned and unconditioned stimulus.

The bird known as the blackcap (Sylvia atricapilla) traditionally migrates from its summer breeding grounds in Central Europe to Spain and Portugal for the winter. State two adaptive advantages of bird migration.

Outline one way in which synchronized oestrus in female lions increases the chances of survival and reproduction of offspring.

Outline one way in which neurons can be altered by memory and learning.

Unconditioned stimulus triggers a response automatically/innately

Sight/smell of food «naturally» triggers salivation in dogs

Conditioned stimulus is a previously neutral stimulus «eg: sound of bell»

that becomes associated with the unconditioned stimulus «and is learned»

Triggers a conditioned response, salivation with sound before food

Award [2 max] if no reference to Pavlov’s investigation.

Food is more abundant

Temperature is more tolerable

More suitable habitat

Alternative 1
Females have their cubs/are lactating at same time

Can suckle/care for each other’s cubs while others hunt

Cubs are more likely to survive when they are raised in a nursery rather than by a solitary mother

Alternative 2
A group of male cubs, of same age, leave the pride at the same time

So can compete for dominance of another pride more effectively

Involve changes in neurons caused by slow-acting neurotransmitters

Neurons make new connections/increase number of synapses

«Short-term» memory depends on change in strength of existing neuronal connections

Long-term potentiation «LTP» is a lasting increase in strength of synaptic transmission

More receptors added to enhance synaptic transmission

This question was surprisingly poorly attempted considering that Pavlovian conditioning is not new to the syllabus. Although many candidates were able to achieve one or 2 marks, very few were able to score 3. Candidates tended to confuse stimulus and response and did not focus on conditioned and unconditioned stimuli.

Most were able to score at least one and many 2 marks for two advantages of bird migration during winter.

Many were also able to score 2 marks for this question on synchronized oestrus in lions.

This question on how neurons can be altered by memory and learning was the one with the weakest candidate answers in this option. Many were confused as to how this was different from question 4(b). Seldom was more than one mark awarded and then for increase in number of synapses.