Biology Practice Test: Human Body Systems
- Human Body Systems
- 10 questions
- 13 minutes
This test covers the main organ systems and how they work together to keep the body alive. Tip: when a question asks about a function, think about which structure has the right shape for it, such as thin walls for gas exchange.
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Question 1
In which part of the lungs does oxygen pass into the blood?
Correct answer: A
Alveoli are tiny air sacs with very thin walls surrounded by capillaries, which makes gas exchange fast. The trachea and bronchi only carry air to them.
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Question 2
Which chamber of the heart pumps oxygen-rich blood out to the rest of the body?
Correct answer: A
The left ventricle pumps oxygen-rich blood into the aorta, so it has the thickest muscular wall. The right ventricle pumps oxygen-poor blood to the lungs.
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Question 3
Which organ absorbs most of the nutrients from digested food, using millions of tiny folds called villi?
Correct answer: C
The villi give the small intestine a huge surface area for absorbing nutrients into the blood. The large intestine mainly absorbs water.
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Question 4
Which structures in the kidneys filter the blood and form urine?
Correct answer: D
Each kidney contains about a million nephrons that filter blood, take back useful substances and leave wastes such as urea in the urine.
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Question 5
In which order does a nerve signal usually travel through a neuron?
Correct answer: D
Dendrites receive signals, the cell body processes them, and the axon carries the impulse to its terminals. There, neurotransmitters pass the signal to the next cell.
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Question 6
How does a vaccine protect a person from a disease?
Correct answer: A
A vaccine shows the immune system harmless parts or weakened forms of a pathogen. Memory cells then allow a fast, strong response if the real pathogen appears later.
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Question 7
A loud noise startles a hiker, and within seconds her heart beats faster and her breathing speeds up. Which glands release the hormone behind this response?
Correct answer: B
The adrenal glands release adrenaline (epinephrine) into the blood, which prepares the body for fight or flight. Thyroid hormones control metabolic rate over a longer time.
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Question 8
What connects a skeletal muscle to a bone?
Correct answer: B
Tendons attach muscles to bones, so a contracting muscle can pull the bone. Ligaments connect one bone to another bone at a joint.
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Question 9
On a hot day, a person's body temperature starts to rise. Which response helps bring it back down?
Correct answer: B
Sweat cools the skin as it evaporates, and wider vessels near the skin let more heat escape. Shivering and narrowing vessels are responses to cold. This is an example of negative feedback.
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Question 10
Where does the chemical digestion of proteins begin?
Correct answer: C
Pepsin in the acidic stomach starts breaking proteins into smaller chains. The mouth begins the chemical digestion of starch, not proteins.
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