---
title: "Structures for Survival"
description: "Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behaviour, and reproduction"
canonical: https://lightmysky.com/learn/science/structures-for-survival-mt_8VA40Tumth
source: https://lightmysky.com/learn/science/structures-for-survival-mt_8VA40Tumth.md
retrieved: 2026-10-19
---

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# Structures for Survival

Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behaviour, and reproduction

Subject: Science · Area: Organisms & Life Processes · Ages 9 to 10
Page: https://lightmysky.com/learn/science/structures-for-survival-mt_8VA40Tumth

## Ready when they can

- Give examples of external structures and their survival functions (e.g. thorns for protection, claws for catching prey)
- Give examples of internal structures and their functions (e.g. heart pumps blood, lungs take in air)
- Construct a reasoned argument linking a specific structure to how it helps the organism survive or reproduce

## Lesson: Structures for Survival

Every plant and animal has structures, or parts, that help it survive. Some structures are external, which means you can see them on the outside. Others are internal, hidden inside the body.

**Example.** A cactus has a thick, waxy stem. In the desert, rain is rare, so the cactus stores water inside its stem for weeks or months. The thick stem is a structure, and storing water is its function.

*(drawing: Think of a cactus stem as a water tank. After a rare desert rain, the stem fills up with stored water, and the cactus sips it slowly for weeks.)*

Internal structures work too, even though you cannot see them. A heart pumps blood to carry oxygen around the body. Lungs take in air so the body gets the oxygen it needs.

**Example.** A porcupine is covered in sharp quills. If a predator comes too close, the quills poke it. This external structure protects the porcupine and helps it survive.

**Tip.** When you explain a structure, always name the function too. Say what the part is, then say what job it does. That is how you build a strong argument.

**Recap.** Every survival structure, external or internal, has a job that helps the plant or animal live, grow, or reproduce.

## Practice

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

## Needs first

- [How Plant Parts Work](https://lightmysky.com/learn/science/how-plant-parts-work-mt_6xsEXxKdUX)
- [Cells, Tissues & Organs](https://lightmysky.com/learn/science/cells-tissues-and-organs-mt_C7FNeIDGc6)
- [Skeletons & Muscles](https://lightmysky.com/learn/science/skeletons-and-muscles-mt_g4YSiOCS8g)

## Opens up

- [Evidence-Based Classification](https://lightmysky.com/learn/science/evidence-based-classification-mt_B8lX8OCzGu)