Keystone Test Keystone Biology: Ecology and Homeostasis 1 — Questions and Answers
Question 1: What is homeostasis?
- The maintenance of a stable internal environment (Correct answer)
- The process of cell division
- The transfer of energy through a food chain
- The mutation of DNA
Correct answer: The maintenance of a stable internal environment
Homeostasis is the ability of an organism to maintain stable internal conditions despite external changes.
Question 2: Which organ system is primarily responsible for maintaining body temperature in humans?
- Integumentary system (Correct answer)
- Digestive system
- Reproductive system
- Skeletal system
Correct answer: Integumentary system
The integumentary system (skin, sweat glands) helps regulate body temperature through sweating and blood vessel changes.
Question 3: What is a food web?
- A complex network of feeding relationships in an ecosystem (Correct answer)
- A single path of energy transfer
- A diagram showing photosynthesis
- A map of an organism's habitat
Correct answer: A complex network of feeding relationships in an ecosystem
A food web shows multiple overlapping food chains and the complex feeding relationships among organisms.
Question 4: Which level of the energy pyramid contains the MOST available energy?
- Producers (Correct answer)
- Primary consumers
- Secondary consumers
- Tertiary consumers
Correct answer: Producers
Producers (plants) capture solar energy and have the most energy available in the pyramid.
Question 5: What is the role of decomposers in an ecosystem?
- Breaking down dead organisms and recycling nutrients (Correct answer)
- Producing food through photosynthesis
- Eating primary consumers
- Converting sunlight to chemical energy
Correct answer: Breaking down dead organisms and recycling nutrients
Decomposers like fungi and bacteria break down dead matter and return nutrients to the soil.
Question 6: What is a negative feedback loop in homeostasis?
- A response that counteracts a change to restore balance (Correct answer)
- A response that amplifies a change
- A process that stops cell division
- A mechanism for genetic mutation
Correct answer: A response that counteracts a change to restore balance
Negative feedback loops detect a deviation and trigger responses that bring the system back to its set point.
Keystone Test Keystone Biology: Ecology and Homeostasis 1
What is homeostasis?