Compare scurvy and rickets using stated dietary evidence
Match each deficiency cause to its biological role.
Exam scope and assessment notes
Mapped to the named 0973 section using teaching from the corresponding single-science course. A 0973-specific review of every Core and Supplement objective is still in progress. Written practice is self-checked; it does not demonstrate supervised laboratory competence or award an official Cambridge grade. This qualification reports two grades on the 9–1 scale; confirm the entry route for your zone and exam series.
Before you begin
- Recall large and small nutrient molecules, cell membranes and enzyme specificity.
- Use the stated diagram keys and evidence; models are not to scale.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Which vitamin supports collagen formation?
What you will learn
- Match each deficiency cause to its biological role.
- Explain why a symptom is weaker evidence than a documented deficiency.
Use the named cause and its function
| Component | Examples of sources | Role |
|---|---|---|
| Vitamin C | Citrus fruit, peppers | Connective tissue; deficiency: scurvy |
| Vitamin D | Oily fish; labelled fortified foods | Calcium use; deficiency: rickets |
Keep the two causes separate
Scurvy is associated with inadequate vitamin C; rickets in children can result from vitamin D deficiency. Vitamin C supports connective-tissue formation, while vitamin D supports calcium absorption and normal bone mineralisation.
Both are deficiency conditions, but one nutrient is not a substitute for the other. A menu rich in vitamin C can still lack vitamin D, and a vitamin D source does not establish vitamin C adequacy.
Reason from an explicit case
In written comparisons, use documented nutrient supply and the named function. A photograph of a symptom alone is insufficient to diagnose the disease or identify the only possible cause.
A useful explanation has a chain: missing component → impaired function → associated condition. Keep the dietary cause separate from a symptom or a treatment recommendation; this is school biology, not personal medical guidance.
Sources for this lesson
Pause and explain
Which causal pair is correct?
Worked example
Case A explicitly lacks vitamin C; case B explicitly lacks vitamin D during childhood. Match the named diseases and functions.
Show the worked solution
- A: vitamin C and connective tissue.
- B: vitamin D and bone mineralisation.
- Name scurvy for A and rickets for B.
Answer A is associated with scurvy; B with rickets in children, using the stated deficiency evidence.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Complete: scurvy is caused by inadequate ___; rickets can be caused by inadequate ___.
Give me a hint
Use the two vitamin names.
Compare my reasoning
- Scurvy: vitamin C.
- Rickets: vitamin D.
Vitamin C; vitamin D.
Look for these in your work
- Correct pairing.
- No mineral/vitamin swap.
A menu includes citrus fruit but no stated vitamin D source. Which deficiency requirement is better addressed by the supplied evidence?
Give me a hint
Do not infer unstated food contents.
Compare my reasoning
- Citrus supplies vitamin C.
- Vitamin D adequacy remains unestablished.
The evidence addresses vitamin C supply better; vitamin D adequacy is not established.
Look for these in your work
- Use the supplied source.
- Limit the vitamin D conclusion.
A poster says “bleeding gums prove scurvy; bent legs prove vitamin D deficiency”. Improve the evidence wording.
Give me a hint
Association is not unique diagnosis.
Compare my reasoning
- Name the possible deficiency associations.
- Explain that symptoms need further evidence.
These observations can be consistent with the named deficiencies, but they alone do not prove either diagnosis or its cause.
Look for these in your work
- Retain correct associations.
- Remove proof claims.
Common mistakes
- Do not swap vitamin C and D.
- A symptom alone does not prove a dietary cause.
What can you explain now?
Which causal pair is correct?
Compare with the explanation
Vitamin D deficiency can cause rickets in children.
This is the named association.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Write each missing vitamin, impaired function and named disease as a separate chain.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.