# A scientist studied a section of DNA and found that it contained 120 bases. The scientist then observed the process of transcription and translation to produce a protein. Describe the roles of messenger RNA (mRNA) and transfer RNA (tRNA) in the synthesis of a protein.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 1.4 DNA, RNA and protein synthesis · Describe · 5 marks

> A section of DNA contains 120 bases. The scientist observed transcription and translation occurring in a cell to produce a protein from this DNA.

## Mark scheme (5 marks)

1. mRNA is produced/made in the nucleus (during transcription)
2. mRNA carries the genetic code / base sequence from the nucleus to the ribosome
3. tRNA carries / brings specific amino acids to the ribosome
4. tRNA has an anticodon that pairs / matches with the complementary codon on the mRNA
5. amino acids are joined together (in the order determined by the mRNA sequence) to form a protein / polypeptide (at the ribosome)

## Key terms

- [messenger RNA (mRNA)](https://www.gradenine.co.uk/glossary/messenger-rna-mrna)
- [transfer RNA (tRNA)](https://www.gradenine.co.uk/glossary/transfer-rna-trna)
- [transcription](https://www.gradenine.co.uk/glossary/transcription)
- [translation](https://www.gradenine.co.uk/glossary/translation)

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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/a-scientist-studied-a-section-of-b77f76ae) · Published by Druglandscape Ltd.