# Explain how the structure of the nuclear envelope is related to its function in a eukaryotic cell.

> IB DP Biology Standard Level (2023 syllabus) — A2.2 Cell structure · Explain · 4 marks

## Mark scheme (4 marks)

1. The nuclear envelope consists of two phospholipid bilayer membranes (double membrane), which forms a physical barrier separating the nucleus from the cytoplasm.
2. Nuclear pores are present in the nuclear envelope and allow selective transport of molecules (such as mRNA and proteins) between the nucleus and the cytoplasm.
3. The outer membrane of the nuclear envelope is continuous with the rough endoplasmic reticulum (rER), linking nuclear activity to protein synthesis and processing.
4. The double membrane / enclosed compartment protects DNA from potentially damaging cytoplasmic processes and allows transcription and translation to be spatially separated, enabling post-transcriptional modification of mRNA before export.

## Key terms

- [nuclear envelope](https://www.gradenine.co.uk/glossary/nuclear-envelope)
- [eukaryotic cell](https://www.gradenine.co.uk/glossary/eukaryotic-cell)

## Related

- [Revision notes for IB DP Biology Standard Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-structure-of-the-96316441) · Published by Druglandscape Ltd.