Three ways to feed

The idea

Heterotrophs break down food outside the body and then absorb it (fungi), take in whole material and break it down inside, or, as parasites, derive nutrition from plants or animals without killing them.

Mushroom, tiger, tick

A mushroom, a tiger and a tick do not make their own food. Each one gets it in its own way.

How many different ways of feeding do you think there are?

• Three
• One
• Seven

Sort the feeders

Sort each example by the way it gets its food.

Different strategies

Organisms are adapted to their environment, so the way they feed differs. Some fungi, like bread moulds, yeast and mushrooms, break down food outside the body and then absorb it. Others take in whole material and break it down inside their bodies. Parasites such as cuscuta, ticks, lice, leeches and tape-worms derive nutrition from plants or animals without killing them.

Heterotrophs break down food outside the body and then absorb it (fungi), take in whole material and break it down inside, or, as parasites, derive nutrition from plants or animals without killing them.

Notes

Heterotrophs break down food outside the body and absorb it (fungi), take in whole material and break it down inside, or live as parasites on plants or animals without killing them.

Check yourself

How do fungi such as mushrooms get their food?

A tick gets food from an animal without killing it. What is such an organism called?

Which pair breaks food down outside the body and then absorbs it?

Cuscuta (amar-bel) derives nutrition from another plant without killing it. Which feeding strategy is this?

• They break it down outside the body and then absorb it — correct. Yes!
• They take in whole food and break it down inside. That is the strategy of organisms that take in whole material, such as animals. Fungi break food down outside the body.
• They make it from carbon dioxide and water. That is autotrophic nutrition, as in green plants. Fungi are heterotrophs.
• An autotroph. Autotrophs make their own food from carbon dioxide and water. A tick takes its nutrition from an animal.
• A parasite — correct. Yes!
• A fungus that digests food outside. Fungi like bread moulds break food down outside the body. A tick takes nutrition from an animal without killing it, which is a parasitic strategy.
• Cuscuta and tick. These are parasites, which derive nutrition from other living organisms without killing them.
• Amoeba and tiger. These take in food and break it down inside their bodies.
• Bread mould and yeast — correct. Yes!
• Parasitic — correct. Yes!
• Breaking down food outside the body. That is the strategy of fungi such as bread moulds, yeast and mushrooms.
• Taking in whole material and breaking it down inside. Cuscuta does not take in whole material; it draws nutrition from another plant.