Year 9 Science • AC9S9U01 • Authored homework
Body systems, stimuli and regulation
Compare how nervous and endocrine body systems coordinate responses to stimuli, and explain how negative feedback helps maintain stable internal conditions. Use topic vocabulary, evidence and clear cause-and-effect reasoning in longer answers.
Part A
Short-answer questions
Define stimulus and response using a biological example.
Name the receptor, control centre and effector in a simple response pathway.
Explain why the nervous system usually produces faster responses than the endocrine system.
What is a hormone, and how does it travel around the body?
Define homeostasis in your own words.
What is negative feedback?
Give one example of a body condition that is regulated by negative feedback.
Explain the role of an effector in a response to a stimulus.
Describe one difference between a reflex response and a voluntary response.
Correct this misconception: “Negative feedback makes the original change bigger.”
Part B
Long-answer questions
Trace the response pathway when a person touches a hot object and quickly pulls their hand away. Include stimulus, receptor, control centre, effector and response.
Compare nervous coordination and endocrine coordination using speed, signal type, pathway and duration of response.
Explain how negative feedback helps regulate body temperature when a person becomes too hot.
Explain how the body may respond to a drop in blood glucose, including the role of hormones.
A student says body systems work independently. Use an example to show how two or more systems work together to regulate the body.
Describe how heart rate, breathing rate and sweating can change during exercise and how these changes help the body.
Create a labelled flow chart for a homeostatic feedback loop and explain each step.
Evaluate why maintaining stable internal conditions is important for enzyme function and cell survival.
Interpret a possible graph of body temperature before, during and after exercise. Describe the pattern and explain the regulation involved.
Write a full explanation of one regulated body system, identifying the stimulus, response pathway, feedback mechanism and final effect.
Part C
Research and understanding task
Research one homeostatic mechanism such as temperature regulation, blood glucose control or water balance. Summarise the stimulus, receptor/control system, effectors, response and why negative feedback is important.