Attempt either A or B. Write your answer in the space below and on page 29. A Describe the mode of action of recreational drugs and the effects on the body of their repeated use. OR B Describe the contents of vaccines and the design of clinical trials used to establish their effectiveness. You may use labelled diagrams where appropriate.

Scottish Highers Human Biology Neurotransmitters: Attempt either A or B. Write you

Attempt either A or B - Scottish Highers Human Biology - Question 15 - 2023

Question 15

Attempt either A or B. Write your answer in the space below and on page 29. A Describe the mode of action of recreational drugs and the effects on the body of thei... show full transcript

Worked Solution & Example Answer:Attempt either A or B - Scottish Highers Human Biology - Question 15 - 2023

Step 1

A Describe the mode of action of recreational drugs and the effects on the body of their repeated use.

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Answer

Recreational drugs can act as:

Agonists: These drugs stimulate receptors in the brain, mimicking the action of neurotransmitters.
Antagonists: These can block receptors, preventing natural neurotransmitters from exerting their effects.

The action of these drugs leads to several changes in mood, cognition, and behavior:

Drugs alter neurotransmission, affecting mood and craving behavior.
Repeated use can lead to addiction, where tolerance is built over time, necessitating larger doses to achieve the same effects.
Over time, receptors may become desensitized, decreasing their response to the drug.

Key Effects of Repeated Use:

Tolerance: Increased doses are needed to achieve the same high because the number or sensitivity of receptors decreases.
Craving: An increased number of receptors can lead to heightened craving for the drug.
Withdrawal: If a user stops taking the drug, they may experience withdrawal symptoms as their body readjusts to its absence.

Step 2

B Describe the contents of vaccines and the design of clinical trials used to establish their effectiveness.

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Answer

Vaccines typically contain:

Antigens: These are substances that induce an immune response and can be in the form of inactivated or weakened pathogens, or parts of the pathogen such as proteins.
Adjuvants: These enhance the body’s immune response to the vaccine.

Clinical Trials:

Clinical trials are critical in evaluating vaccine safety and efficacy. The design generally follows these steps:

Randomization: Subjects are randomly assigned to either the vaccine group or a placebo group, which helps eliminate bias.
Control Groups: A control group receives a placebo, ensuring reliable comparisons between those receiving the vaccine and those who do not.
Blinding: In double-blind trials, neither participants nor researchers know who receives the vaccine or placebo, enhancing the validity of the results.
Reliability: A significant number of participants are required to ensure statistical power in determining effectiveness.
Outcome Measurement: Results are compared to establish any statistically significant differences in effectiveness between the two groups.