[Maximum number: 2]
Fig. 1.1 is a diagram showing the structure of a section of a DNA molecule.
Fig. 1.1
(a)
Name the two bases forming the base pair at X in Fig. 1.1 and give a reason for your answer. bases reason
[ 2 ]
[Maximum number: 1]
DNA replication is an important event in the cell cycle.
(a)
Fig. 2.1 shows pairing between two bases, X and Y, in a DNA molecule.
Fig. 2.1
[ 1 ]
(i)
Name the type of bond shown by the dotted lines between the bases.
[ 1 ]
(a)
Complete the table to show three ways in which the structure of DNA differs from RNA.
[ 3 ]
[Maximum number: 1]
The diagram shows three routes, X, Y and Z, through which substances can pass across a cell surface membrane.
Which correctly shows the routes for vitamin D, which is fat soluble, and vitamin C, which is water soluble?
vitamin D
vitamin C
Y
X
X
Y
X
Z
Z
Y
(a)
Fig. 3.1 is a diagram of a monomer of the nucleic acid, messenger RNA.
Fig. 3.1
[ 3 ]
(i)
Name D, E and F in Fig. 3.1.
D
E
F
[ 3 ]
[Maximum number: 4]
Catalase is an enzyme that catalyses the breakdown of hydrogen peroxide, a toxic waste product of metabolism.
Fig. 3.1 shows the results of an investigation into the effect of hydrogen peroxide concentration on the rate of the catalase-controlled reaction, with and without the presence of two different inhibitors.
Fig. 3.1
(a)
Describe the structure of DNA.
[ 4 ]
(a)
DNA is involved in the processes of replication and transcription.
Complete Table 4.2 by using a tick to indicate which features apply to each of the processes. Use a cross ( X ) for features that do not apply.
The first row has been completed for you.
Table 4.2
[ 4 ]
[Maximum number: 1]
The diagram shows part of a DNA molecule.
Which regions contain phosphate groups?
A
1 and 2
B
1 and 4
C
3 and 4 only
D
2, 3 and 4
[Maximum number: 2]
DNA and RNA are important biological molecules that are involved in the production of polypeptides.
(a)
Fig. 4.1 shows two nucleotides joined by a covalent bond.
Fig. 4.1
[ 2 ]
(i)
Fig. 4.1 represents part of a DNA molecule, not part of an RNA molecule.
Explain why.
[ 1 ]
(ii)
Name the covalent bond between the two nucleotides.
[ 1 ]