Oxford AQA International A-level · Biology (9610)

DNA, genes and chromosomes: Practice Questions

5 multiple-choice questions marked as you go, and 5 written questions with worked solutions. All on DNA, genes and chromosomes.

10 questions26 marksFree, no account

Question 1

1 mark

A nucleotide was isolated and found to contain a phosphate group, a ribose sugar, and the base Uracil. In which molecule would this nucleotide be found?

Question 2

1 mark

Which of the following describes the precise action of DNA helicase during the process of DNA replication?

Question 3

1 mark

Which of the following correctly describes the DNA found within the mitochondria of a eukaryotic cell?

Question 4

1 mark

In eukaryotes, much of the nuclear DNA does not code for polypeptides. Where are non-coding multiple repeats of base sequences primarily located on a chromosome?

Question 5

1 mark

In the provided diagram of a chromosome, the arrow points to a specific fixed position labelled X where a particular gene is located. What is the correct biological term for position X?

Question 6

2 marks

Define the term genome and explain how it differs from a single gene located at a specific locus.

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Question 7

5 marks

Explain why the genetic code is described as degenerate and describe how this feature provides a degree of protection against the effects of base substitution mutations.

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Question 8

3 marks

Identify the specific role of DNA polymerase during semi-conservative replication and state the type of bond it catalyzes between nucleotides.

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Question 9

5 marks

DNA replication is a semi-conservative process that occurs during the S-phase of the cell cycle.

(a) Describe the role of DNA helicase and DNA polymerase during the process of replication. (3 points)

(b) Explain why the term 'semi-conservative' is used to describe this process. (2 points)

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Question 10

6 marks

Compare the structures and functions of mRNA and tRNA.

(a) Identify two structural differences between an mRNA molecule and a tRNA molecule. (2 points)

(b) Explain the importance of the anticodon on the tRNA molecule in ensuring the correct primary structure of a protein is formed. (2 points)

(c) Describe the process by which amino acids are joined together at the ribosome during translation. (2 points)

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