# "Explain" questions — Edexcel A-Level Biology A: Salters-Nuffield (9BN0)

> 141 questions · biology

## How to answer

WHAT + WHY. Every point paired with a because. Structure: X happens because Y. This causes Z because … Assessment Objective: AO2. Every "explain" answer on this spec is marked against exactly this pattern.

## Sample questions

1. [A student eats a large meal containing a lot of sugar. Explain how the body detects the change in blood glucose concentr…](https://www.gradenine.co.uk/q/a-student-eats-a-large-meal-00d71cb4)
2. [Explain how the sliding filament model accounts for muscle contraction, including the roles of actin, myosin and ATP in …](https://www.gradenine.co.uk/q/explain-how-the-sliding-filament-model-01e280ab)
3. [A patient is diagnosed with HIV. Over several years, the number of white blood cells in the patient's body decreases sig…](https://www.gradenine.co.uk/q/a-patient-is-diagnosed-with-hiv-021f326e)
4. [A student investigates the effect of light intensity on the rate of photosynthesis in pond weed. As light intensity incr…](https://www.gradenine.co.uk/q/a-student-investigates-the-effect-of-03d35cf7)
5. [A person is infected with a new strain of influenza (flu) virus for the first time. Explain how the immune system respon…](https://www.gradenine.co.uk/q/a-person-is-infected-with-a-0659d211)
6. [A coral reef ecosystem contains the following food chain: phytoplankton → zooplankton → small reef fish → reef sharks. S…](https://www.gradenine.co.uk/q/a-coral-reef-ecosystem-contains-the-0a707adc)
7. [Tuberculosis (TB) is a communicable disease caused by the bacterium Mycobacterium tuberculosis. It is spread when an inf…](https://www.gradenine.co.uk/q/tuberculosis-tb-is-a-communicable-disease-0ab39720)
8. [A patient visits their doctor and is told they have high blood cholesterol levels and high blood pressure. The doctor ex…](https://www.gradenine.co.uk/q/a-patient-visits-their-doctor-and-0ad07d6c)

## Related

- [Edexcel A-Level Biology A: Salters-Nuffield (9BN0) revision notes](https://www.gradenine.co.uk/learn/edexcel-a-level-biology-a-salters-nuffield-9bn0)
- [Edexcel A-Level Biology A: Salters-Nuffield (9BN0) past papers](https://www.gradenine.co.uk/past-papers/edexcel-a-level-biology-a-salters-nuffield-9bn0)
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