ACT SSC Psychology Unit 2: Biological Bases of Behaviour — Flashcards & Quiz

Q1: Describe the structure of a neuron and explain how it transmits information.

A neuron consists of dendrites (receive signals), cell body/soma (integrates signals and contains nucleus), axon (transmits electrical impulse via action potential), myelin sheath (insulates axon for faster transmission via saltatory conduction) and axon terminals (release neurotransmitters). Transmission is electrical within the neuron (action potential) and chemical between neurons (neurotransmitters across the synapse).

Q2: Explain the process of synaptic transmission step by step.

Step 1: Action potential arrives at the axon terminal. Step 2: Calcium ions enter the terminal, triggering vesicles to release neurotransmitters into the synaptic cleft. Step 3: Neurotransmitters cross the cleft and bind to specific receptors on the postsynaptic neuron. Step 4: This produces excitatory or inhibitory postsynaptic potentials. Step 5: Neurotransmitters are removed by reuptake (back into presynaptic neuron), enzymatic degradation or diffusion.

Q3: Describe the roles of four key neurotransmitters and their links to behaviour.

Dopamine: reward, motivation, motor control; excess linked to schizophrenia, deficiency to Parkinson’s disease. Serotonin: mood, sleep, appetite regulation; low levels linked to depression and anxiety. GABA (gamma-aminobutyric acid): main inhibitory neurotransmitter, reduces neural excitability; low GABA linked to anxiety disorders. Glutamate: main excitatory neurotransmitter, essential for learning and memory; excess causes excitotoxicity and cell death.

Q4: Describe the organisation of the human nervous system.

The nervous system comprises the central nervous system (CNS: brain and spinal cord) and peripheral nervous system (PNS). The PNS includes the somatic nervous system (voluntary movement, sensory input) and autonomic nervous system (ANS: involuntary functions). The ANS divides into the sympathetic nervous system (fight-or-flight arousal) and parasympathetic nervous system (rest-and-digest recovery).

Q5: Describe the functions of the four cerebral lobes.

Frontal lobe: executive function, planning, personality, voluntary movement (motor cortex), speech production (Broca’s area). Parietal lobe: somatosensory processing (touch, temperature, pain), spatial awareness, integration of sensory information. Temporal lobe: auditory processing, language comprehension (Wernicke’s area), memory (hippocampus nearby). Occipital lobe: visual processing via the primary visual cortex.

Q6: What is cerebral lateralisation and what evidence supports it?

Cerebral lateralisation is the tendency for certain cognitive functions to be more dominant in one hemisphere. Left hemisphere: language (Broca’s and Wernicke’s areas), logical reasoning, sequential processing. Right hemisphere: spatial processing, facial recognition, emotional expression, holistic processing. The corpus callosum connects hemispheres and enables communication. Split-brain studies (Sperry & Gazzaniga, 1960s) provided direct evidence by studying patients whose corpus callosum was severed.

Q7: What is neuroplasticity and why is it important?

Neuroplasticity is the brain’s ability to reorganise itself by forming new neural connections throughout life. Types: experience-expectant (during critical periods — requires typical environmental input for normal development), experience-dependent (throughout life — driven by individual learning and experiences). Neuroplasticity enables learning, memory formation, recovery from brain injury and adaptation to environmental changes.

Q8: How do twin studies help researchers understand the role of genetics in behaviour?

Twin studies compare concordance rates between monozygotic (MZ, identical) twins who share 100% of their DNA and dizygotic (DZ, fraternal) twins who share approximately 50%. If MZ twins show higher concordance than DZ twins for a trait, this suggests genetic influence. The difference between MZ and DZ concordance rates helps estimate heritability. Twin studies are strengthened when twins are reared apart, controlling for shared environment.

Q1: Dendrites carry electrical impulses away from the cell body toward the axon terminals.

Answer: FALSE

Dendrites receive incoming signals from other neurons and carry them toward the cell body. It is the axon that carries electrical impulses away from the cell body toward the axon terminals.

Q2: Neurotransmitters are released from the postsynaptic neuron into the synaptic cleft.

Answer: FALSE

Neurotransmitters are released from the presynaptic neuron (specifically from vesicles in the axon terminal) into the synaptic cleft. They then travel across the cleft to bind with receptors on the postsynaptic neuron.

Q3: GABA is the primary inhibitory neurotransmitter in the brain, reducing neural excitability.

Answer: TRUE

GABA (gamma-aminobutyric acid) is the brain’s primary inhibitory neurotransmitter. It reduces neural activity and excitability. Low GABA levels are associated with anxiety disorders, and drugs like benzodiazepines work by enhancing GABA’s effects.

Q4: The somatic nervous system controls involuntary functions such as heart rate and digestion.

Answer: FALSE

The somatic nervous system controls voluntary movements and transmits sensory information. Involuntary functions (heart rate, digestion, breathing) are controlled by the autonomic nervous system (ANS).

Q5: Broca’s area, located in the frontal lobe, is primarily responsible for speech production.

Answer: TRUE

Broca’s area is located in the left frontal lobe and is responsible for speech production and language output. Damage to Broca’s area results in Broca’s aphasia — difficulty producing fluent speech while comprehension remains relatively intact.

Neurons and Synaptic Transmission

The structure of neurons and the process of synaptic transmission form the basis of all neural communication. BSSS assessments require accurate diagrams, step-by-step explanations and the ability to link disruptions in synaptic processes to psychological conditions and drug treatments.

Neurotransmitters and Behaviour

Understanding the roles of dopamine, serotonin, GABA and glutamate, and their links to specific disorders, is core knowledge. BSSS exams may present symptoms and ask you to identify the neurotransmitter system involved, requiring application of biological knowledge to clinical scenarios.

Brain Structure, Lateralisation and Neuroplasticity

Cortical localisation (which brain regions control which functions), lateralisation (hemisphere specialisation) and neuroplasticity (the brain’s capacity for change) are key topics. Supporting these concepts with case studies and research evidence is essential for BSSS extended responses.

Brain Research Methods

Comparing EEG, fMRI, PET and lesion studies in terms of spatial and temporal resolution, invasiveness and applications is a common BSSS assessment task. Understanding the strengths and limitations of each method demonstrates scientific literacy.

What does ACT SSC Psychology Unit 2 cover?

Unit 2 covers the biological bases of behaviour including neuron structure and function, synaptic transmission, neurotransmitters (dopamine, serotonin, GABA, glutamate), the nervous system organisation, brain structure and localisation, cerebral lateralisation, neuroplasticity and the role of genetics in behaviour.

Are these flashcards aligned to the BSSS curriculum?

Yes — every flashcard and quiz question is mapped to the ACT Board of Senior Secondary Studies (BSSS) Psychology curriculum for Unit 2: Biological Bases of Behaviour.

How should I study brain anatomy for BSSS exams?

Use labelled diagrams to memorise brain regions and their functions. Create flashcards linking neurotransmitters to their roles and associated disorders. Practise applying biological concepts to explain behaviour, as BSSS exams test application as well as knowledge.