# 4-mark practice questions — IB DP Biology Standard Level (2023 syllabus)

> 290 questions · biology

## How to answer

4-mark questions are the shortest levels-of-response band. Aim for four scientific ideas, each in its own short sentence.

## Sample questions

1. [Explain how the structure of the rough endoplasmic reticulum (rER) is related to its role in the production and processi…](https://www.gradenine.co.uk/q/explain-how-the-structure-of-the-00781636)
2. [Explain why DNA replication must occur before mitosis and describe one consequence if replication failed to occur.](https://www.gradenine.co.uk/q/explain-why-dna-replication-must-occur-00f9bb7e)
3. [Distinguish between prokaryotic and eukaryotic cells in terms of their internal organisation.](https://www.gradenine.co.uk/q/distinguish-between-prokaryotic-and-eukaryotic-cells-010b1bb8)
4. [Explain how the primary structure of a protein determines its three-dimensional shape and, therefore, its function.](https://www.gradenine.co.uk/q/explain-how-the-primary-structure-of-05a8117a)
5. [Explain how sex-linked inheritance can result in a phenotypic ratio that differs between males and females in the offspr…](https://www.gradenine.co.uk/q/explain-how-sex-linked-inheritance-can-result-05adfa02)
6. [Explain how the structure of a capillary is adapted to allow the exchange of substances between blood and surrounding ti…](https://www.gradenine.co.uk/q/explain-how-the-structure-of-a-06041870)
7. [Explain how the adaptations of a named aquatic insect larva allow it to obtain sufficient oxygen in a fast-flowing, well…](https://www.gradenine.co.uk/q/explain-how-the-adaptations-of-a-066f64d4)
8. [Explain how non-competitive inhibitors reduce the rate of an enzyme-catalysed reaction.](https://www.gradenine.co.uk/q/explain-how-non-competitive-inhibitors-reduce-the-07a82c7b)

## Related

- [IB DP Biology Standard Level (2023 syllabus) revision notes](https://www.gradenine.co.uk/learn/ib-dp-biology-standard-level-2023-syllabus)
- [IB DP Biology Standard Level (2023 syllabus) past papers](https://www.gradenine.co.uk/past-papers/ib-dp-biology-standard-level-2023-syllabus)
- [Practise with AI marking (free)](https://www.gradenine.co.uk/start)