# Cells and Systems

This worksheet develops your understanding of how cells form the basic unit of life and how they work together in systems ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17320)). You will examine the structures and functions of plant and animal cells, compare single-celled and multicelled organisms, and explore how body systems keep humans healthy ([Outcome](https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17321)).

## Exercises

1. **Plant and animal cells both contain a nucleus and mitochondria. Name two structures found in plant cells that are NOT found in animal cells.**

 __________________ and __________________

2. **The table below shows four organisms. Classify each as single-celled or multicelled, and explain one reason for your choice.**

 | Organism | Single-celled or Multicelled? | Reason |
 |---|---|---|
 | Amoeba | | |
 | Oak tree | | |
 | Paramecium | | |
 | Grizzly bear | | |

3. **A red blood cell is placed in pure water. The cell swells and bursts. Which process explains what happened?**

 A) Diffusion
 
 B) Osmosis
 
 C) Active transport
 
 D) Photosynthesis

4. **Match each human body system with its primary function.**

 | System | Function |
 |---|---|
 | Respiratory system | A) Breaks down food and absorbs nutrients |
 | Circulatory system | B) Exchanges oxygen and carbon dioxide with the air |
 | Digestive system | C) Removes waste products from the body |
 | Excretory system | D) Carries oxygen and nutrients to all body tissues |

5. **Your heart rate increases when you exercise. Describe this as a response to a stimulus, naming the stimulus and the body's response.**

 Stimulus: __________________
 
 Body's response: __________________

6. **Bone tissue contains bone cells that produce a hard mineral substance. Explain how this structure supports the function of the skeletal system.**

 ____________________________________________________________________________

 ____________________________________________________________________________

## Answer Key

1. Cell wall and chloroplast (accept: vacuole, plasmodesmata, or other plant-specific structures).

2. Amoeba: single-celled (it is one cell that performs all life functions); Oak tree: multicelled (it is made of many cells organized into tissues and organs); Paramecium: single-celled (one cell that carries out all functions); Grizzly bear: multicelled (made of many specialized cells organized into tissues, organs and systems).

3. B) Osmosis.

4. Respiratory system: B; Circulatory system: D; Digestive system: A; Excretory system: C.

5. Stimulus: exercise (or increased physical activity); Body's response: heart rate increases (accept: increased blood flow, faster pumping of blood).

6. The hard mineral structure of bone cells makes bone strong and rigid, which allows the skeletal system to support the body's weight and protect internal organs.

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*AILI homework sheet · language en · model claude-haiku-4-5-20251001 · generated 2026-09-17 · id 39c5ab63-15b6-41b9-b3d4-cab35f78f794*

### Sources

- node:n1: Unit B: Cells and Systems (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17317)
- node:n2: Outcomes for Science, Technology and Society (STS) and Knowledge (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17318)
- node:n3: *Students will:* Investigate living things; and identify and apply scientific ideas used to interpret their general stru (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17319)
- node:n4: *Students will:* Investigate and describe the role of cells within living things - describe the role of cells as a basic (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17320)
- node:n5: Students will: Interpret the healthy function of human body systems, and illustrate ways the body reacts to internal and (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17321)
- node:n6: *Students will:* Describe areas of scientific investigation leading to new knowledge about body systems and to new medic (https://goa-cc-uat-aili-app-001.azurewebsites.net/explore/node/17322)