Circulatory & Respiratory Systems — Drills · Grade 7 Science
Chapter: Body Organization, Transport & MovementWhat these drills covers
By the end of Circulatory & Respiratory Systems you should be able to:
- I can explain circulatory & respiratory systems.
- I can use evidence, a model, and stated assumptions to support a biological explanation.
4 questions, multiple choice and written answer, each with a worked explanation.
Vocabulary used: ventilation, gas exchange, capillary, artery, vein.
Problem 1
Which structure supplies the pumping action in circulation?
- Heart
- Food molecule
- Lung air alone
- Microscope lens
Answer and explanation
Heart
The heart pumps blood; lungs supply gas exchange and ventilation functions.
Problem 2
Why do respiratory and circulatory systems both matter to oxygen delivery?
Answer and explanation
Respiration-related surfaces exchange gases, while circulation moves oxygen-containing blood toward tissues. Cells also require exchange at the destination.
Problem 3
Is exhaled air pure carbon dioxide?
Answer and explanation
No. It remains a mixture including nitrogen, oxygen, carbon dioxide, and water vapor in different proportions.
Problem 4
Why is “every artery carries oxygen-rich blood” inaccurate?
Answer and explanation
Arteries are defined by direction from the heart; the lung-circuit artery carries blood toward gas exchange before it becomes oxygen-rich.