Question 1: Define a synapse and explain its role in nerve impulse transmission.

Answer: A synapse is a junction between two neurons where nerve impulses are transmitted from one neuron to another, enabling communication within the nervous system.

Question 1: Describe the sequence of events that occur during synaptic transmission, including the role of neurotransmitters.

Answer: When a nerve impulse reaches the synaptic knob, calcium ions enter, causing vesicles containing neurotransmitters to fuse with the membrane. Neurotransmitters are released into the synaptic cleft and bind to receptors on the postsynaptic neuron, triggering a new impulse.

Question 1: Calculate the speed of nerve impulse transmission if the distance between two neurons is 2 metres and the impulse takes 0.5 seconds to travel this distance.

Answer: Speed = Distance / Time = 2 metres / 0.5 seconds = 4 metres per second.

Question 2: A neurotransmitter is released at a concentration of 0.2 mol/dm³ in the synaptic cleft. If the volume of the cleft is 1 x 10⁻⁶ dm³, how many moles of neurotransmitter are released?

Answer: Number of moles = Concentration × Volume = 0.2 mol/dm³ × 1 × 10⁻⁶ dm³ = 2 × 10⁻⁷ mol.

Question 1: Outline a simple experiment to investigate the effect of a drug on synaptic transmission in nerve cells, including variables and safety precautions.

Answer: Students could use nerve tissue samples exposed to different concentrations of the drug. The independent variable is drug concentration, the dependent variable is the rate of nerve impulse transmission, and control variables include temperature and pH. Safety precautions include wearing gloves, handling chemicals carefully, and disposing of waste properly.

Question 1: In an experiment, the average time for a nerve impulse to cross the synapse was measured as 0.002 seconds. If the distance between neurons is 0.5 metres, what is the impulse transmission speed? How does this compare to typical nerve speeds?

Answer: Speed = 0.5 m / 0.002 s = 250 metres per second. This is faster than typical nerve speeds (about 30-120 m/s), indicating a highly efficient transmission in this scenario.

Question 1: Explain the importance of synapses in the nervous system and describe how they contribute to complex behaviour.

Answer: Synapses allow neurons to communicate efficiently, enabling the nervous system to process complex information, coordinate responses, and adapt to changes. They enable integration of signals from multiple sources, contributing to functions like learning, memory, and reflexes.

Question 1: Describe how understanding synaptic function has led to the development of drugs for neurological disorders such as depression or epilepsy.

Answer: Understanding synaptic mechanisms has enabled the development of drugs that modulate neurotransmitter levels or receptor activity, helping to restore normal nerve function in conditions like depression (e.g., SSRIs) or epilepsy.