This set covers the five lessons in living systems and classification. Questions run from easy to harder. Write your answer first, then open the worked answer.
The keys and data in this set are invented for practice. Use your own syllabus notes and the Cambridge 0610 subject page for the exact wording and depth expected.
Questions
1. A tomato seedling on a windowsill becomes taller over two weeks, its stem bends towards the window, and it releases carbon dioxide during the night. Name the life process shown by each observation.
Show answer
Becoming taller shows growth. Bending towards the window shows sensitivity, a response to light. Releasing carbon dioxide at night shows respiration.
2. The dry mass of a group of seedlings (invented data) was 0.12 g at the start and 0.30 g after ten days. Calculate the increase in dry mass and the percentage increase.
Show answer
Increase = 0.30 − 0.12 = 0.18 g.
Percentage increase = 0.18 ÷ 0.12 × 100 = 1.5 × 100 = 150%.
Check: 0.12 × 2.5 = 0.30, so the final mass is 2.5 times the start, which is an increase of 150%.
3. A student says, “A cloud moves across the sky and gets bigger, so it is alive.” Give two reasons the evidence is weak.
Show answer
The cloud is moved by wind, not by its own action, so this is not the life process of movement. Getting bigger by gaining water vapour is not the growth of an organism made of cells. Also, there is no evidence of respiration, sensitivity, reproduction, excretion or nutrition.
4. Use this invented key. A specimen has no feathers, four legs and dry scaly skin. Name it.
| Step | Statement | Go to |
|---|---|---|
| 1a | Has feathers | Bird |
| 1b | No feathers | 2 |
| 2a | No legs | Snake |
| 2b | Four legs | 3 |
| 3a | Moist skin | Frog |
| 3b | Dry scaly skin | Lizard |
Show answer
1b (no feathers), 2b (four legs), 3b (dry scaly skin). The specimen is a lizard.
5. Using the same key, identify a specimen with no feathers and no legs. Explain why the key did not need to ask about skin.
Show answer
1b, then 2a. It is a snake. Once the specimen has no legs, the key reaches a name at 2a, so no more features are needed.
6. Write a dichotomous key with two steps to separate an eagle, a frog and a cat.
Show answer
1a Has feathers: eagle. 1b No feathers: go to 2.
2a Has moist skin: frog. 2b Has fur: cat.
Any key with two opposite statements at each step, using features you can observe, is acceptable.
7. A single-celled organism has no nucleus, and its DNA is free in the cytoplasm. Name its kingdom and give one more feature of the group.
Show answer
It is a prokaryote (for example a bacterium). Another feature: prokaryotes are single-celled, and bacterial cells have a cell wall.
8. A student classifies a bat as a bird because it flies. Correct the answer using two features.
Show answer
A bat is a mammal. It has fur and feeds its young with milk from mammary glands. It has no feathers. Flying is a way of moving, not a feature that defines a group.
9. Rewrite this name correctly: felis catus. State the genus, and say which of Felis silvestris and Canis lupus is more closely related to Felis catus.
Show answer
Felis catus, with a capital F for the genus. The genus is Felis. Felis silvestris is more closely related, because it is in the same genus.
10. State two differences between a virus and a bacterial cell.
Show answer
A bacterial cell has a cell membrane and cytoplasm, but a virus has neither. A bacterial cell can reproduce on its own, but a virus can reproduce only inside a host cell. Other acceptable answers: a bacterial cell has a cell wall, and a virus has a protein coat with DNA or RNA.
11. Explain why a virus cannot be classified as a prokaryote.
Show answer
Prokaryotes are cells, with a cell membrane, cytoplasm and DNA inside the cell. A virus is not a cell, and it has no cytoplasm or membrane. It is a particle with genetic material in a protein coat, which needs a host cell to reproduce.
If you got these wrong
| If the error was in | It usually means | Go to |
|---|---|---|
| Questions 1 to 3 | Life processes were listed but not tied to evidence | Distinguish a life process from a single observation |
| Questions 4 to 6 | Keys were followed from memory, or written with unclear features | Use a simple identification key |
| Questions 7 and 8 | Groups were chosen by habit or movement, not by features | Explain classification by shared features |
| Question 9 | Name format or relatedness reasoning | Interpret a scientific name |
| Questions 10 and 11 | Virus and cell structure were mixed up | Compare virus and cell descriptions |
Record each slip in your mistake log and retest queue, and retry a fresh question on the same skill a few days later.
If the same type of error keeps returning, a teacher in online one-to-one Biology tuition can go through your answers with you.