The big idea: All animals are heterotrophs. In holozoic nutrition they take food into the body and digest it inside.
The points to remember
- Ingestion: food is taken into the gut.
- Digestion: enzymes break large molecules into small ones, inside the body.
- Absorption: small molecules pass into the blood.
- Assimilation: cells use them to build molecules and release energy.
- Egestion: undigested food leaves the body.
Remember it as: In, break down, take up, use, out.
Real example: the common frog. A frog catches insects with its sticky tongue and swallows them whole (ingestion); enzymes in its stomach and intestine digest them, and the products are absorbed into its blood.
Trap: Holozoic digestion is internal. Fungi digest food outside their bodies: that is saprotrophic nutrition, not holozoic.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it with your first topic free to keep:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Start Studying Free Full access to Aimnova Pro · cancel anytime
How it is asked: Expect a description of feeding to classify, or the stages of holozoic nutrition in order.
IB-style questionOutline[4 marks]
Outline the stages of holozoic nutrition in an animal.
Model answer plan
See the answer broken into clear points, with guidance on how each point earns marks.