---
title: "Fungi: Hyphae, Spores and Digestion Outside the Body"
description: "A fungus grows as a network of threads that secretes enzymes into its surroundings and takes back what dissolves, which is why the body plan is all surface. That habit makes fungi the main decomposers"
canonical: https://lightmysky.com/learn/science/fungi-hyphae-spores-and-digestion-outside-the-body-mt_qfp2nuk1IH
source: https://lightmysky.com/learn/science/fungi-hyphae-spores-and-digestion-outside-the-body-mt_qfp2nuk1IH.md
retrieved: 2026-09-12
---

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# Fungi: Hyphae, Spores and Digestion Outside the Body

A fungus grows as a network of threads that secretes enzymes into its surroundings and takes back what dissolves, which is why the body plan is all surface. That habit makes fungi the main decomposers on land and, with the same machinery, serious pathogens of plants.

Subject: Science · Area: Organisms & Life Processes · Ages 18 to 19
Page: https://lightmysky.com/learn/science/fungi-hyphae-spores-and-digestion-outside-the-body-mt_qfp2nuk1IH

## Ready when they can

- Relate hyphal growth to the demands of external digestion
- Compare a mycorrhizal partnership with a fungal infection and say what differs mechanically
- Explain why antifungal drugs are harder to make selective than antibacterial ones

## Lesson: Threads that digest the world outside

Fungi are eukaryotes with nuclei that cannot make their own food, since they carry no chlorophyll. They feed as saprobes on dead matter by digesting outside the body: they release enzymes around themselves and absorb the small molecules that result.

That habit explains the body plan. A fungus grows as a mass of thin threads, the mycelium of hyphae, because more thread surface means more room to release enzymes and absorb food. Spores are the tiny cells that spread new colonies on wind or water.

**Example.** Fallen leaves rot because fungi dissolve them and release carbon and nitrogen for reuse, and without fungi dead matter would pile up. A mycorrhiza shows the friendly side: the fungus trades water and minerals for plant sugars, aiding both. A parasite shows the other side, pushing feeding threads into living tissue to digest and absorb it.

**Tip.** Fungal infections resist standard antibiotics because fungi are eukaryotes like us, leaving few selective targets such as the chitin wall. That shared machinery is why antifungal drugs are harder to design than antibacterial ones.

**Recap.** Threads digest outside, absorb inside, recycle the land, and partner or parasitise with the same tools.

## Practice

8 questions on this page, each with its working shown.

## Needs first

- [Decomposers and the Rate of Decay](https://lightmysky.com/learn/science/decomposers-and-the-rate-of-decay-mt_4152TrzD6A)
- [Protists: The Eukaryotes That Are Not Plants, Animals or Fungi](https://lightmysky.com/learn/science/protists-the-eukaryotes-that-are-not-plants-animals-or-fungi-mt_CHb8H727nW)

## Opens up

- [Land Plants: Vascular Tissue and a Life Cycle That Alternates](https://lightmysky.com/learn/science/land-plants-vascular-tissue-and-a-life-cycle-that-alternates-mt_DFtQ2mCZSm)