mark scheme answers

Question 1

what is the difference between endogenous pacemakers and exogenous zeitgebers

Answer 1

endogenous pacemakers are body clocks which regulate biological rhythms whereas exogenous zeitgebers are cues that entrain our biological rhythms

Question 2

explain the fight or flight response with reference to Xavier’s experience

Answer 2

•the fight/ flight response is generated by the sympathetic branch of the ANS
•the hypothalamus stimulates the SNS
•the SNS stimulates the adrenal gland to release adrenaline into the bloodstream and noradrenaline is released
•effects of adrenaline —
•once the stressor is gone the PNS acts to dampen the stress response and return the heart and breathing rate to normal levels

Question 3

explain the difference between infradian rhythms and ultradian rhythms

Answer 3

the rhythms have different durations: infradian rhythms have a duration of over 24 hours whereas ultradian rhythms are cycles that last less than 24 hoursb

Question 4

Explain how a drug (Zapurpain) might affect the process of synaptic transmission through inhibition

Answer 4

•the drug mimics the effect of inhibitory neurotransmitters, stimulation of postsynaptic receptors will result in inhibition of the postsynaptic receptor site
•when an inhibitory neurotransmitter binds to the post- synaptic receptors it makes the post- synaptic cell less likely to fire
•increases the negative charge of the neuron making it less likely to fire
•reduced brain activity may lead to reduced pain

Question 5

what is a similarity between fMRIs and ERPs?

Answer 5

•fMRIs and ERPs are both non- invasive and do not use radiation (risk- free)
•fMRIs and ERPs both measure brain activity linked to events/ tasks

Question 6

what is a difference between fMRIs and ERPs?

Answer 6

•fMRIs have poor temporal resolution whereas ERPs have good temporal resolution
•fMRIs have good spatial resolution whereas ERPs have poor spatial resolution

Question 7

outline split-brain research

Answer 7

•’split-brain’ patients have had their corpus callosum severed
•sperry’s methodology
•sperry’s tactile/ visual findings

Question 8

split brain research evaluation

Answer 8

•’split-brain’ research has enabled discoveries of lateralisation of function
•experiments on split-brain research were scientific
•lack of controls
•issues of generalisability

Question 9

use your knowledge of genotype and phenotype to explain how identical twins can be not identical people

Answer 9

•they have identical genotypes
•they to dot have identical phenotypes
•influenced by environmental factors

Question 10

describe the structure and function of a neuron

Answer 10

•neurons enable communication within the nervous system
•the cell body (soma) contains the generic material
•the dendrites expand from the cell body, they carry information towards the cell body
•dendrites can receive information from other neurons
•axons carry messages away from the cell body
•terminal buttons are at the end of axons, these make synaptic connections with other cells
•axon terminals contain neurotransmitters

Question 11

describe the divisions of the nervous systems

Answer 11

•the NS is divided into the central and peripheral nervous system
•the CNS compromises of the brain and spinal cord
•the PNS is further decided into the somatic NS and the autonomic NS
•the somatic NS consists of sensory and motor neurons to carry sensory and motor information to and from the CNS and also enables reflex actions
•the autonomic NS acts largely unconsciously
•the autonomic NS is divided into the sympathetic nervous system and the parasympathetic nervous system
•the sympathetic NS prepares us for fight or flight
•the PNS balances the sympathetic NS providing ‘rest and digest’ functions