Chemistry 9701 · AS & A Level · States of matter

States of matter — practice question

DNA is a key biochemical molecule.
(a)[5]

DNA has a double helical arrangement made of two linked strands. Draw a block diagram of DNA with two repeat units in each strand. Label every part, and show and label the bonds between the strands.

(b)[2]

DNA stores genetic information. Outline the main stages in DNA replication.

(c(i))[1]

At the first stage of DNA fingerprinting, a DNA sample must be broken into shorter fragments. What could be used to carry out this fragmentation?

(c(ii))[1]

Name the analytical method used to separate these short fragments.

(c(iii))[1]

After the fragments have been separated, what could the DNA fingerprint be treated with to show the position of the bands?

(c(iv))[1]

A sample of blood, believed to have come from the suspect, was discovered at a crime scene. The DNA from the blood sample, and from four possible suspects, was analysed. Using this evidence, circle the suspect who should be arrested.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: sugar-phosphate DNA backbone

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