Environment and Homeostasis

Name:

Date:

📚 Part 1: Multiple Choice

1. Which environmental factor most directly affects thermoregulation?

Temperature

Salinity

Oxygen concentration

Light intensity

2. Check all that apply: Which responses are typical homeostatic reactions to increased environmental heat?

Sweating

Vasodilation (widening of blood vessels)

Shivering

Increased metabolic heat production

3. A marine fish moves into water of higher salinity. Which statement best describes an immediate homeostatic response?

Gain water by osmosis

Actively excrete salt and adjust urine concentration

Stop gill exchange completely

Switch to anaerobic respiration

4. Which body system coordinates the fastest homeostatic responses to sudden environmental change?

Nervous system

Endocrine system

Immune system

Digestive system

✏️ Part 2: Short Answers & Activities

Success criteria: I can list environmental factors that affect homeostasis; explain how a homeostatic response restores balance; give an organism example; suggest an extension research topic.

Differentiation strategies: Sentence starters and glossary provided for students needing support. Challenge prompts and extension tasks available for advanced learners. Work in pairs if helpful.

5. List three environmental factors that commonly challenge an organism's homeostasis:

6. Choose one factor (write it here: __________). In 2–3 sentences explain a homeostatic mechanism that responds to this factor. Use this starter if you need it: "When the environment becomes _____ (e.g. hot or salty) the organism..."

7. Match each environmental factor (left) with a typical homeostatic response (right). Draw lines between the columns.

A. High external temperature

B. Increased water salinity

C. Low oxygen (hypoxia)

1. Increased ventilation and heart rate

2. Sweating and vasodilation

3. Active salt excretion or concentrated urine

8. Short analysis: A person's core temperature rises from 37°C to 39°C during a heatwave. Describe two immediate homeostatic responses and name one serious risk if the condition continues for hours.

Extension activities (for advanced learners): Research and prepare a short summary on one of the following—coral bleaching from warming seas, kangaroo physiological adaptations to drought, or how Antarctic fish prevent ice crystal formation. Include a recent study or data point.

Teacher note: Use the answers to assess understanding and support group presentations: check correct identification of factors, clarity of mechanistic explanations and suggested examples.