The 11 systems & what they do
Before you read
Test yourself first: 5 questions
Question 1 of 5
Which best describes the relationship 'cells → tissues → organs → organ systems'?
Answer: B. This is the biological hierarchy of organization, moving from the smallest unit (cells) to the largest (organ systems).
Question 2 of 5
The original source of energy for most ecosystems is the:
Answer: B. The Sun's energy enters ecosystems through producers via photosynthesis.
Question 3 of 5
The largest artery in the human body is the:
Answer: B. The aorta carries oxygenated blood from the left ventricle out to the body — the largest artery.
Question 4 of 5
The longest bone in the human body is the:
Answer: A. The femur (thigh bone) is the longest and strongest bone in the body.
Question 5 of 5
The smallest bone in the human body, located in the ear, is the:
Answer: B. The stapes (stirrup) in the middle ear is the smallest bone in the body.
Keep the streak going with more questions like these, each with a full rationale.
