Plant and Animal Cells: Structures and Functions — Answers
Answer sheet with model answers and success criteria for the Year 8 cells & classification worksheet.
Success TutoringWorksheetsAnswer sheetYear 8 · Science · Cells & ClassificationPlant and Animal Cells: Structures and Functions — Answers
Part A: Cell structures
Read the passage, then answer the questions.
Cell theory states that all living things are made of one or more cells, that the cell is the basic unit of life, and that new cells come only from existing cells dividing.
Inside cells are structures with special jobs. The nucleus controls the cell. The cell membrane surrounds the cell and controls what moves in and out. The cytoplasm is where many chemical reactions take place, and mitochondria release energy from food.
Plant cells also have a rigid cell wall made of cellulose, chloroplasts for photosynthesis, and a large permanent vacuole filled with cell sap that keeps the cell firm.
- nucleus
- cell membrane
- cytoplasm
- mitochondria
- chloroplasts
- cell wall
- controls what enters and leaves the cell
- controls the cell's activities and contains genetic information (DNA)
- release energy from food during respiration
- a rigid outer layer that supports and protects the cell
- jelly-like fluid where many chemical reactions happen
- contain chlorophyll and carry out photosynthesis
Answer: nucleus → controls the cell's activities and contains genetic information (DNA); cell membrane → controls what enters and leaves the cell; cytoplasm → jelly-like fluid where many chemical reactions happen; mitochondria → release energy from food during respiration; chloroplasts → contain chlorophyll and carry out photosynthesis; cell wall → a rigid outer layer that supports and protects the cell
Answer: cells
Answer: divide
Part B: Plant or animal?
Circle where each structure is found, then write True or False.
- Aplant cells only
- Banimal cells only
- Cboth plant and animal cells
Answer: plant cells only
Plant cells (and fungi and bacteria) have cell walls; animal cells do not.
- Aplant cells only
- Banimal cells only
- Cboth plant and animal cells
Answer: both plant and animal cells
Both plant and animal cells have a nucleus to control the cell.
- Aplant cells only
- Banimal cells only
- Cboth plant and animal cells
Answer: plant cells only
Only plant cells (and some protists) have chloroplasts, because only they carry out photosynthesis.
- Aplant cells only
- Banimal cells only
- Cboth plant and animal cells
Answer: both plant and animal cells
Every cell has a cell membrane. In plant cells it lies just inside the cell wall.
- Aplant cells only
- Banimal cells only
- Cboth plant and animal cells
Answer: both plant and animal cells
Both plant and animal cells need to release energy from food, so both have mitochondria.
Answer: True
Root cells receive no light, so they cannot carry out photosynthesis and do not need chloroplasts.
Answer: False
Without a rigid cell wall, animal cells are usually irregular or rounded in shape. Plant cells are more regular and box-like.
Part C: One cell or many?
Unicellular organisms, such as bacteria and amoebas, are made of a single cell. Multicellular organisms, such as plants and animals, are made of many cells.
In multicellular organisms, cells are specialised: their shape and structures suit a particular job.
- Aa mushroom
- Ban amoeba
- Can oak tree
- Da frog
Answer: an amoeba
An amoeba carries out all life processes within a single cell. The others are multicellular.
- red blood cell
- nerve cell
- root hair cell
- sperm cell
- long thin fibres that carry messages around the body
- long thin extension that increases surface area to absorb water
- disc shape with no nucleus, giving more room to carry oxygen
- tail for swimming towards the egg
Answer: red blood cell → disc shape with no nucleus, giving more room to carry oxygen; nerve cell → long thin fibres that carry messages around the body; root hair cell → long thin extension that increases surface area to absorb water; sperm cell → tail for swimming towards the egg
Answer: They receive the most light, so having many chloroplasts lets them carry out more photosynthesis to make food for the plant.
Model answer: Similarities: both have a nucleus, a cell membrane, cytoplasm and mitochondria. Differences: plant cells have a cell wall, chloroplasts and a large permanent vacuole, while animal cells do not (animal cells may have small temporary vacuoles); plant cells usually have a regular, box-like shape and animal cells an irregular shape. Plant cells need chloroplasts because plants make their own food by photosynthesis, whereas animals eat food. They need a cell wall and a large vacuole full of sap to keep the cells firm and support the plant, because plants have no skeleton.
Success criteria:
- Two correct similarities
- Three correct differences
- Explains chloroplasts in terms of making food
- Explains cell wall/vacuole in terms of support
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.