A-Level AQA 2026 Psychology Paper 2 Mark Scheme with verified answers

A-Level AQA 2026 Psychology Paper 2 Mark Scheme with verified answers 1. What is a neuron? - ANSWER The basic building blocks of the nervous system. 2. 3. They are nerve cells that process and transmit messages through electrical and chemical signals. 4. What is a Synapse? - ANSWER Gap between neurons 5. Structure of sensory neurons. - ANSWER Long dendrites and short axons 6. Cell body in the middle. 7. Function of sensory neurons. - ANSWER Carry messages from the peripheral nervous system to the central nervous system. 8. Structure of relay neurons. - ANSWER Short dendrites and short axons 9. Function of relay neurons. - ANSWER Connect sensory neurons to motor or other relay neurons 10. Structure of motor neurons. - ANSWER Short dendrites and long axons 11. Function of motor neurons. - ANSWER Connects the central nervous system to effectors, such as muscle and glands. 12. Describe conditions in the neuron when it is at rest. - ANSWER Inside the neuron is negatively charged relative to the outside. This is because there are relatively more negatively charged ions inside the neuron and more positively charged ions outside the mirror. 13. Describe conditions in the neuron when it is active. - ANSWER The inside of the neuron is more positively charged compared to the outside. This is a tiny spike of electrical activity called an action potential. 14. Action potential. - ANSWER Causes a wave of electrical activity to move along an Axon. 15. Process of synaptic transmission. - ANSWER 1) An electrical impulse (action potential) moves along the Axon of the presynaptic neuron. 2) inside the neuron becomes positively charged compared to the outside. 3) Vesicles release neurotransmitters into the synaptic gap. 4) The neurotransmitters cross the synaptic gap. 5) Neurotransmitters bind to receptor sites on the post synaptic neuron. 6) An electrical impulse is either triggered or prevented from being triggered in the post synaptic neuron during summation. 16. In relation to neurons, what is meant by excitation? - ANSWER An excitatory neuron increases the neurons positive charge, making it more likely to fire and cause depolarisation in the post synaptic neuron. 17. In relation to neurons, what is meant by the term inhibition? - ANSWER Inhibitory neurotransmitters decrease the charge in the neuron, making it more negative and less likely to fire, causing hyperpolarisation in the post synaptic neuron. 18. What is Process of synaptic transmission? - ANSWER Excitatory and inhibitory effects are summed If the net effect is excitatory, the neuron is more likely to fire. If the net effect is inhibitory, the neuron is less likely to fire. 19. What is the function of the endocrine system? - ANSWER Secretes hormones that regulate processes such as growth, reproduction, and metabolism by body cells 20. What does the endocrine system secrete? And from what? - ANSWER The endocrine system secrete hormones from glands into the blood stream. 21. What does the endocrine system use to transmit messages? - ANSWER Hormones there secreted into the blood stream and affect any cell in the body with the receptor for that specific hormone. 22. Function of the anterior pituitary gland. - ANSWER Regulates physiological functions such as growth, reproduction and stress. 23. Hormones secreted from the anterior pituitary gland. - ANSWER AC TH growth hormone. 24. Function of the posterior pituitary gland. - ANSWER Involved in creating positive feedback loops in the body. 25. Colemans released from the posterior pituitary gland. - ANSWER Oxytocin. 26. Function of the adrenal cortex. - ANSWER Release of glucose and fats for energy immunosuppression. 27. Hormones released from the adrenal cortex. - ANSWER Cortisol. 28. Function of the adrenal medulla. - ANSWER Fight and flight response along with any associated characteristics. 29. Hormones released by the adrenal medulla. - ANSWER Adrenaline and noradrenaline. Function of the testes. - ANSWER Male sexual characteristics and muscle mass. Hormones released from the testes. - ANSWER testosterone Function of the ovaries. - ANSWER Female sexual characteristics, menstruation and pregnancy. describe a fight or flight response - ANSWER when a stressor is perceived, the hypothalamus triggers activity in the sympathetic branch of the ANS (physiological arousal) and adrenaline is released from the adrenal medulla which triggers physiological changes (e.g. increased heart rate) and the arousal level necessary for the fight or flight response (after the threat has passed the parasympathetic branch of the ANS returns to body to its resting state) what are neurons - ANSWER basic building blocks of the nervous system; nerve cells name the three types of neurons - ANSWER sensory neuron, relay neuron, motor neuron describe sensory neurons - ANSWER carry messages from the PNS to the CNS and have long dendrites and short axons describe relay neurons - ANSWER connect sensory neurons to motor and other relay neurons and have short dendrites and axons describe motor neurons - ANSWER connect the CNS to effectors (muscles and glands) and have short dendrites and long axons describe the structure of neurons - ANSWER dendrites carry impulses from neighbouring cells towards the soma (cell body) which contains a nucleus, then the axon carries the impulse along the length of the neuron (the myelin sheath protects the axon and speeds up the electrical transmission of the impulse) while nodes of Ranvier also speed up the transmission by making the signal 'jump' the gap before the terminal buttons communicate with the next neuron across the synapse describe why neurons fire - ANSWER when a neuron is in its resting state the inside of the cell is negatively charged (compared to the outside) so when the neuron is activated by a stimulus the inside of the cell becomes positively charged, creating an action potential which creates an electrical impulse that travels down the axon to the end of the neuron what is synaptic transmission - ANSWER the process by which neighbouring neurons communicate with each other by sending chemical messages across the synaptic cleft that separates them describe the process of synaptic transmission - ANSWER at the terminal buttons the impulse is converted to a chemical message by synaptic vesicles (found by the terminal buttons) which release the neurotransmitter (NT) across the synaptic gap before it binds to (complementary) postsynaptic receptor sites and produces either an excitatory effect or an inhibitory one and the NT is the recycled by the pre-synaptic neuron in a process called reuptake describe the role of acetylcholine (ACh) - ANSWER found at each point where a motor neuron meets a muscle and, upon its release, causes muscles to contract what is excitation - ANSWER when a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron, increasing the likelihood that the neuron will fire and pass on the electrical impulse what is inhibition - ANSWER When a neurotransmitter, such as serotonin, makes the charge of the postsynaptic neuron more negative, decreasing the likelihood that the neuron will fire and pass on the electrical impulse