Which statement, A to D, describes the function of DNA polymerase?

• break the hydrogen bonds between complementary bases

• make phosphodiester bonds between adjacent nucleotides

• make phosphodiester bonds between polynucleotides

• make the hydrogen bonds between complementary bases

Which of the following nucleotides contains uracil?

• A

• B

• C

• C

DNA is made up of two polynucleotide chains.

Which of the bonds, A to D, forms between two nitrogenous bases holding the two polynucleotide chains together?

• phosphodiester

• ionic

• covalent

• hydrogen

The following table describes the approximate percentage mass of different chemical elements in organic polymers.

Which of the rows, A to D, is correct?

• A

• B

• C

• D

DNA is formed from three main groups of molecules: pentose sugars, phosphate groups and nitrogenous bases. The bases can be divided into purines and pyrimidines.

Identify the two purines below

• A

• B

• C

• D

DNA carries the genetic code which is non-overlapping and degenerate.

Which of the options, A to D, contains the correct definitions for non-overlapping and degenerate code?

• Each nucleotide is only part of one triplet of bases and the molecule breaks down easily.

• The genes follow straight after each other and the molecule breaks down easily

• Each nucleotide is only part of one triplet of bases and more than one triplet codes for a specific amino acid

• The genes follow straight after each other and more than one triplet codes for a specific amino acid

Which of the statements, A to D, shows that the genetic code is degenerate?

• CCA and CCT code for proline

• rRNA is manufactured in the nucleolus

• tRNA is not complementary to DNA

• uracil is not found in DNA

The following statements are about the structure of DNA. Which of the following statement(s) is / are true?

Statement 1:

Purine bases pair with pyrimidine bases.

Statement 2:

Phosphodiester bonds link adjacent nucleotides.

Statement 3:

There are always equal amounts of adenine and guanine.

• 1, 2 and 3

• Only 1 and 2

• Only 2 and 3

• Only 1

An anticodon sequence of five successive tRNA molecules involved in protein synthesis was analysed and found to have the following percentage base composition. Adenine 40; Cytosine 27; Guanine 13; Thymine 0; Uracil 20 %
Which row shows the percentage base composition of the template strand of the original DNA molecule?

• Row A

• Row B

• Row C

• Row D

A length of DNA has the base sequence AATCGCGGTCGCTCA.

Select the row that shows the correct complementary DNA strand and the sequence of mRNA made during transcription of the DNA sequence above

• Row A

• Row B

• Row C

• Row D