Digestion, Absorption & Food Molecules — Drills · Grade 7 Science
Chapter: Body Organization, Transport & MovementWhat these drills covers
By the end of Digestion, Absorption & Food Molecules you should be able to:
- I can explain digestion, absorption & food molecules.
- 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: digestion, enzyme, absorption, small intestine, surface area.
Problem 1
Which describes absorption?
- Food crosses the intestinal lining into transport
- Chewing reduces piece size
- A diagram label gets larger
- All energy is created
Answer and explanation
Food crosses the intestinal lining into transport
Absorption is boundary crossing; chewing is mechanical processing.
Problem 2
Why can equal masses in smaller pieces be processed faster under matched conditions?
Answer and explanation
Smaller pieces can provide more exposed surface for contact. The explanation requires comparable materials and reaction conditions.
Problem 3
Why is grinding alone not complete chemical digestion?
Answer and explanation
It changes piece size and surface area but does not necessarily break the relevant chemical bonds into absorbable components.
Problem 4
How does more exchange area help the absorption model?
Answer and explanation
It provides more surface across which materials can move under suitable conditions, rather than making food molecules appear from nothing.