Question 1: Define a synapse and describe its main function in nerve signal transmission.

Answer: A synapse is a junction between two neurons where nerve signals are transmitted from one neuron to another, primarily through chemical messengers called neurotransmitters.

Question 2: Explain the process of synaptic transmission, including the role of neurotransmitters.

Answer: Synaptic transmission begins when an electrical nerve impulse reaches the synaptic terminal. This causes neurotransmitters stored in synaptic vesicles to be released into the synaptic cleft. These chemicals then bind to receptor sites on the postsynaptic neuron, initiating a new electrical impulse. The process allows the nerve signal to be transmitted across the synapse.

Question 3: What is the typical time taken for a nerve impulse to cross a synapse?

Answer: The typical synaptic transmission time is approximately 0.5 milliseconds.

Question 4: A neurotransmitter is released at a rate of 200 molecules per millisecond. How many molecules are released in 2 milliseconds?

Answer: 400 molecules (Rate × Time = 200 molecules/ms × 2 ms = 400 molecules).

Question 5: Identify the main types of neurotransmitters involved in synaptic transmission.

Answer: Dopamine and serotonin

Question 6: Fill in the blank: The process of neurotransmitter release is triggered by a(n) _______ arriving at the synaptic terminal.

Answer: action potential

Question 7: Describe one factor that can affect the efficiency of synaptic transmission.

Answer: Factors such as the concentration of neurotransmitters, the number of receptor sites, or the presence of toxins can affect synaptic efficiency.

Question 8: Propose an experiment to test how a specific drug affects synaptic transmission times. Include variables and safety precautions.

Answer: An experiment could involve measuring the synaptic transmission times in a model organism or neuron culture before and after exposure to the drug. Variables include the drug concentration (independent variable) and transmission time (dependent variable). Safety precautions should include working in a controlled environment, wearing protective gear, and handling chemicals according to safety guidelines.

Question 9: Data shows that the average transmission time across synapses in a sample population is 0.45 milliseconds with a standard deviation of 0.05 ms. What can you infer about the consistency of synaptic transmission times?

Answer: The transmission times are fairly consistent, with most values likely falling between 0.4 and 0.5 milliseconds, indicating reliable synaptic function.

Question 10: Considering the role of synapses, explain how they contribute to reflex actions.

Answer: Synapses enable rapid communication between neurons, allowing reflex actions to occur quickly. In reflexes, sensory neurons transmit signals to the spinal cord, where interneurons connect to motor neurons via synapses. This direct pathway facilitates swift responses to stimuli without the need for conscious thought.