2024HSCShort answer

Q30 (b)

5 marks

Question

The diagram shows a simplified version of the process of polypeptide synthesis.

Explain the importance of mRNA and tRNA in polypeptide synthesis.

Uncropped source page 30 for question 30.b; requires human review and cropping — Reviewed visual · source page 30

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Solution

Criteria	Marks
Provides a thorough explanation of the importance of mRNA and tRNA in polypeptide synthesis	5
Provides a sound explanation of the importance of mRNA and tRNA in polypeptide synthesis	4
Demonstrates some understanding of the importance of mRNA and tRNA in polypeptide synthesis	3
Demonstrates an understanding of mRNA or tRNA	2
Provides some relevant information	1

Sample answer:

mRNA is synthesised from the DNA template in the nucleus during transcription. This mRNA carries the genetic instructions (codon) from the DNA in the nucleus to the ribosomes in the cytoplasm. Once the mRNA reaches the ribosome, the process of translation begins. Each tRNA molecule has an anticodon that pairs with a complementary codon on the mRNA strand. The mRNA codons are read in sequence, and as each tRNA brings its specific amino acid to the ribosome, the polypeptide is assembled.

Supplied marking guidance · human reviewed

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Syllabus alignment

Module 5 · Heredity

DNA and Polypeptide SynthesisAnalyse the function and importance of polypeptide synthesis.
DNA and Polypeptide SynthesisModel transcription and translation, including the roles of mRNA and tRNA.

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