Question 1
Which of these is an example of excretion?
- Removing carbon dioxide made by respiration
- Removing undigested food from the gut
- Taking in oxygen from the air
- Releasing seeds from a plant
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Answer: A (1)
Question 2
A student says that a car engine is alive because it uses fuel and releases waste gases. Use the characteristics of living organisms to suggest why the student is wrong.
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- a car does not grow or develop (1)
- a car does not reproduce (1)
- a car does not respond to its surroundings / control its internal conditions (1)
- burning fuel is not respiration in cells / a car does not respire (1)
- ignore movement, nutrition or excretion (the car appears to show these)
- Max 3
Question 3
Describe four differences between a plant and an animal.
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- plant cells contain chloroplasts, animal cells do not (1)
- plants can photosynthesise, animals cannot (1)
- plant cells have cellulose cell walls, animal cells have no cell walls (1)
- plants store carbohydrate as starch or sucrose, animals store it as glycogen (1)
- animals usually have nervous co-ordination, plants do not (1)
- animals can usually move from one place to another, plants cannot (1)
- Max 4
Question 4
Which statement describes how a fungus such as Mucor feeds?
- It makes glucose by photosynthesis
- It secretes enzymes onto food and absorbs the products
- It engulfs food into a vacuole inside the cell
- It takes in food through a mouth and digests it in a gut
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Answer: B (1)
Question 5
Amoeba and Chlorella are both protoctists. State what a protoctist is, and explain why Chlorella is more like a plant than an animal.
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- a microscopic single-celled organism (1)
- Chlorella has chloroplasts (1)
- so can carry out photosynthesis / like a plant cell (1)
Question 6
Name two structures found in a bacterial cell. State one structure that is found in an animal cell but not in a bacterial cell.
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- first correct structure from: cell wall, cell membrane, cytoplasm, plasmid, circular chromosome (1)
- second correct structure from the same list (1)
- nucleus (1) allow mitochondria
Question 7
Compare the structure of a bacterium with the structure of a virus. Explain why a virus is not classed as a living organism.
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| Level | Marks | What the answer does |
|---|---|---|
| 3 | 5–6 | A detailed comparison covering the structure of both, with clear reasoning for why a virus is not living. Biological terms are used accurately throughout. |
| 2 | 3–4 | Describes the structure of both with some comparison, and gives at least one reason why a virus is not living. Some detail may be missing. |
| 1 | 1–2 | Gives a few simple facts about a bacterium or a virus, with little or no comparison or explanation. |
Indicative content
- a bacterium is a single cell, a virus has no cellular structure
- a bacterium has a cell wall, cell membrane and cytoplasm; a virus has none of these, only a protein coat around its nucleic acid
- a bacterium has a circular chromosome of DNA and plasmids; a virus contains one type of nucleic acid, DNA or RNA
- bacteria are microscopic; viruses are smaller than bacteria
- bacteria can reproduce on their own; a virus can reproduce only inside living cells
- a virus is not living because it has no cellular structure and is parasitic, reproducing only inside host cells