Download Topic Option A Neurobio

Option A: Neurobiology & Behaviour (25 hours)
A.1 Neural development (BCC p513)
Essential idea: Modification of neurons starts in the earliest stages of embryogenesis and continues to the
final years of life.
Nature of science:
1. Use models as representations of the real world—developmental neuroscience uses a variety of animal
models. (1.10)
Understandings:
Applications and skills:
2. The neural tube of embryonic chordates is
11. Application: Incomplete closure of the
formed by infolding of ectoderm followed by
embryonic neural tube can cause spina bifida.
elongation of the tube.
12. Application: Events such as strokes may
3. Neurons are initially produced by differentiation
promote reorganization of brain function.
in the neural tube.
13. Skill: Annotation of a diagram of embryonic
4. Immature neurons migrate to a final location.
tissues in Xenopus, used as an animal model,
Guidance: Terminology relating to embryonic
during neurulation.
brain areas or nervous system divisions is not
required.
5. An axon grows from each immature neuron in
response to chemical stimuli.
6. Some axons extend beyond the neural tube to
reach other parts of the body.
7. A developing neuron forms multiple synapses.
8. Synapses that are not used do not persist.
9. Neural pruning involves the loss of unused
neurons.
10. The plasticity of the nervous system allows it to
change with experience.
A.2 The human brain (BCC p518)
Essential idea: The parts of the brain specialize in different functions.
Nature of science:
1. Use models as representations of the real world—the sensory homunculus and motor homunculus are
models of the relative space human body parts occupy on the somatosensory cortex and the motor
cortex. (1.10)
Understandings:
Applications and skills:
2. The anterior part of the neural tube expands to
11. Application: Visual cortex, Broca’s area, nucleus
form the brain.
accumbens as areas of the brain with specific
3. Different parts of the brain have specific roles.
functions.
4. The autonomic nervous system controls
12. Application: Swallowing, breathing and heart
involuntary processes in the body using centres
rate as examples of activities coordinated by the
located mainly in the brain stem.
medulla.
5. The cerebral cortex forms a larger proportion of 13. Application: Use of the pupil reflex to evaluate
the brain and is more highly developed in
brain damage.
humans than other animals.
14. Application: Use of animal experiments,
6. The human cerebral cortex has become enlarged
autopsy, lesions and fMRI to identify the role of
principally by an increase in total area with
different brain parts.
extensive folding to accommodate it within the
15. Skill: Identification of parts of the brain in a
cranium.
photograph, diagram or scan of the brain.
7. The cerebral hemispheres are responsible for
Guidance: Image of the brain should include the
higher order functions. Guidance: Although
medulla oblongata, cerebellum, hypothalamus,
specific functions can be attributed to certain
pituitary gland and cerebral hemispheres.
areas, brain imagery shows that some activities
16. Skill: Analysis of correlations between body size
are spread in many areas and that the brain can
and brain size in different animals.
even reorganize itself following a disturbance
such as a stroke.
8. The left cerebral hemisphere receives sensory
input from sensory receptors in the right side of
the body and the right side of the visual field in
both eyes and vice versa for the right
hemisphere.
9. The left cerebral hemisphere controls muscle
contraction in the right side of the body and vice
versa for the right hemisphere.
10. Brain metabolism requires large energy inputs.
Option A: Neurobiology & Behaviour (25 hours)
A.3 Perception of stimuli (BCC p526)
Essential idea: Living organisms are able to detect changes in the environment.
Nature of science:
1. Understanding of the underlying science is the basis for technological developments—the discovery that
electrical stimulation in the auditory system can create a perception of sound resulted in the
development of electrical hearing aids and ultimately cochlear implants. (1.2)
Understandings:
Applications and skills:
2. Receptors detect changes in the environment.
12. Application: Red-green colour-blindness as a
Guidance: Humans’ sensory receptors should
variant of normal trichromatic vision.
include mechanoreceptors, chemoreceptors,
13. Application: Detection of chemicals in the air by
thermoreceptors and photoreceptors.
the many different olfactory receptors.
3. Rods and cones are photoreceptors located in the 14. Application: Use of cochlear implants in deaf
retina.
patients.
4. Rods and cones differ in their sensitivities to
15. Skill: Labelling a diagram of the structure of the
light intensities and wavelengths.
human eye. Guidance: Diagram of human eye
5. Bipolar cells send the impulses from rods and
should include the sclera, cornea, conjunctiva,
cones to ganglion cells.
eyelid, choroid, aqueous humour, pupil, lens,
6. Ganglion cells send messages to the brain via the
iris, vitreous humour, retina, fovea, optic nerve
optic nerve.
and blind spot.
7. The information from the right field of vision
16. Skill: Annotation of a diagram of the retina to
from both eyes is sent to the left part of the
show the cell types and the direction in which
visual cortex and vice versa.
light moves. Guidance: Diagram of retina
8. Structures in the middle ear transmit and amplify
should include rod and cone cells, bipolar
sound.
neurons and ganglion cells.
9. Sensory hairs of the cochlea detect sounds of
17. Skill: Labelling a diagram of the structure of the
specific wavelengths.
human ear. Guidance: Diagram of ear should
10. Impulses caused by sound perception are
include pinna, eardrum, bones of the middle ear,
transmitted to the brain via the auditory nerve.
oval window, round window, semicircular
11. Hair cells in the semicircular canals detect
canals, auditory nerve and cochlea.
movement of the head.
A.4 Innate and learned behaviour (BCC p533)
Essential idea: Behavioural patterns can be inherited or learned.
Nature of science:
1. Looking for patterns, trends and discrepancies—laboratory experiments and field investigations helped
in the understanding of different types of behaviour and learning. (3.1)
Understandings:
Applications and skills:
2. Innate behaviour is inherited from parents and so 11. Application: Withdrawal reflex of the hand from
develops independently of the environment.
a painful stimulus.
3. Autonomic and involuntary responses are
12. Application: Pavlov’s experiments into reflex
referred to as reflexes.
conditioning in dogs.
4. Reflex arcs comprise the neurons that mediate
13. Application: The role of inheritance and learning
reflexes.
in the development of birdsong.
5. Reflex conditioning involves forming new
14. Skill: Analysis of data from invertebrate
associations.
behaviour experiments in terms of the effect on
6. Learned behaviour develops as a result of
chances of survival and reproduction.
experience.
15. Skill: Drawing and labelling a diagram of a
7. Imprinting is learning occurring at a particular
reflex arc for a pain withdrawal reflex.
life stage and is independent of the consequences
Guidance: Drawing of reflex arc should include
of behaviour.
the receptor cell, sensory neuron, relay neuron,
8. Operant conditioning is a form of learning that
motor neuron and effector.
consists of trial and error experiences.
9. Learning is the acquisition of skill or knowledge.
10. Memory is the process of encoding, storing and
accessing information.
Option A: Neurobiology & Behaviour (25 hours)
A.5 Neuropharmacology (BCC p541)
Essential idea: Communication between neurons can be altered through the manipulation of the release and
reception of chemical messengers.
Nature of science:
1. Assessing risks associated with scientific research—patient advocates will often press for the speeding
up of drug approval processes, encouraging more tolerance of risk. (4.5)
Understandings:
Applications and skills:
2. Some neurotransmitters excite nerve impulses in
10. Application: Effects on the nervous
postsynaptic neurons and others inhibit them.
system of two stimulants and two
3. Nerve impulses are initiated or inhibited in post-synaptic
sedatives. Guidance: Examples of
neurons as a result of summation of all excitatory and
stimulants are nicotine, cocaine or
inhibitory neurotransmitters received from presynaptic
amphetamines. Examples of sedatives
neurones.
are benzodiazepines, alcohol or
4. Many different slow-acting neurotransmitters modulate
tetrahydrocannabinol (THC).
fast synaptic transmission in the brain.
11. Application: The effect of anesthetics on
5. Memory and learning involve changes in neurones
awareness.
caused by slow-acting neurotransmitters.
12. Application: Endorphins can act as
6. Psychoactive drugs affect the brain by either increasing
painkillers.
or decreasing postsynaptic transmission.
13. Skill: Evaluation of data showing the
7. Anesthetics act by interfering with neural transmission
impact of MDMA (ecstasy) on serotonin
between areas of sensory perception and the CNS.
and dopamine metabolism in the brain.
8. Stimulant drugs mimic the stimulation provided by the
sympathetic nervous system.
9. Addiction can be affected by genetic predisposition,
social environment and dopamine secretion.
A.6 Ethology (BCC p548)
Essential idea: Natural selection favours specific types of behaviour.
Nature of science:
1. Testing a hypothesis—experiments to test hypotheses on the migratory behaviour of blackcaps have
been carried out. (1.9)
Understandings:
Applications and skills:
2. Ethology is the study of animal
Guidance: The seven applications in this sub-topic are intended
behaviour in natural conditions.
to reinforce understanding of the general principles. The
3. Natural selection can change the
applications include a range of types of behaviour and types of
frequency of observed animal
animal. Other examples, including local examples that can be
behaviour.
observed, should also be studied if possible.
4. Behaviour that increases the
6. Application: Migratory behaviour in blackcaps as an example
chances of survival and
of the genetic basis of behaviour and its change by natural
reproduction will become more
selection.
prevalent in a population.
7. Application: Blood sharing in vampire bats as an example of
5. Learned behaviour can spread
the development of altruistic behaviour by natural selection.
through a population or be lost
8. Application: Foraging behaviour in shore crabs as an example
from it more rapidly than innate
of increasing chances of survival by optimal prey choice.
behaviour.
9. Application: Breeding strategies in Coho salmon populations
as an example of behaviour affecting chances of survival and
reproduction.
10. Application: Courtship in birds of paradise as an example of
mate selection.
11. Application: Synchronized oestrus in female lions in a pride
as an example of innate behaviour that increases the chances
of survival and reproduction of offspring.
12. Application: Feeding on cream from milk bottles in blue tits
as an example of the development and loss of learned
behaviour.