DNA and the Production of Proteins (SQA National 5 Biology): Exam Questions

A section of DNA contains a total of 6400 bases of which 32% are guanine.

The number of adenine bases in this section of DNA is

The diagram shows the sequence of bases in a strand of DNA.

Which of the following shows the complementary base sequence for this strand of DNA?

The four DNA bases represented by A, C, G and T make up the genetic code.

Part of the base sequence that codes for a protein is shown.

------ G C A T A T A G A ------

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(i) Name base A and base C.

Base A ............................................................................

Base C ............................................................................

(ii) The sequence shown is only 5% of the bases in this strand.

Calculate the total number of bases in this DNA strand.

[1]

....................................bases

Name the type of molecule that proteins are made from.

Where in a cell would mRNA not be found?

The diagram represents a section of DNA.

Give the term used to describe the structure of a DNA molecule.

The following results show an analysis of the DNA bases contained in a cell.

Which letter in the table represents the base cytosine?

(i) Name the type of molecule coded for by a section of DNA.

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(ii) A mutation occurred in a section of DNA as shown.

original code C A T G T A A A T
mutated code C A T C T A A A T

Describe the effect of this mutation on the molecule produced.

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(iii) State one environmental factor that can increase the rate of mutation.

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