Practice Test GeeksKeystone Test Practice Test
← All Keystone Test Flashcard Decks

Keystone Biology: Ecology and Homeostasis Flashcards

6 cards from real Keystone Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 6 Keystone Biology: Ecology and Homeostasis flashcards as text

  1. What is homeostasis?

    Answer: The maintenance of a stable internal environment

    Homeostasis is the ability of an organism to maintain stable internal conditions despite external changes.

  2. Which organ system is primarily responsible for maintaining body temperature in humans?

    Answer: Integumentary system

    The integumentary system (skin, sweat glands) helps regulate body temperature through sweating and blood vessel changes.

  3. What is a food web?

    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.

  4. Which level of the energy pyramid contains the MOST available energy?

    Answer: Producers

    Producers (plants) capture solar energy and have the most energy available in the pyramid.

  5. What is the role of decomposers in an ecosystem?

    Answer: Breaking down dead organisms and recycling nutrients

    Decomposers like fungi and bacteria break down dead matter and return nutrients to the soil.

  6. What is a negative feedback loop in homeostasis?

    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.

How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

  1. pa.gov — Test dates, test delivery, eligibility, exam format, retake policy, score release, time limit · verified Oct 2026