EduNinja
Question rangeD1.2.7—Complementary base pairing
[Maximum number: 1]

The diagram shows the translation of a mRNA molecule.

Question image

[Content provided by The National Human Genome Research Institute.]

A tRNA molecule with anticodon CAG carries the amino acid phenylalanine. Which codon of mRNA will the tRNA join?

A

CTG

B

CAG

C

GTC

D

GUC

[Maximum number: 1]

The base sequences of a short section of DNA are shown, together with mRNA that has been transcribed from it and one of the tRNA anticodons that could be used to translate the mRNA.

DNA strand 1 A-C-G-G-C-A-T-T-A-G-C-T-A tRNA anticodon U-U-A

DNA strand 2 T-G-C-C-G-T-A-A-T-C-G-A-T mRNA U-G-C-C-G-U-A-A-U-C-G-A-U

Which strand of DNA is transcribed and to which codon in the mRNA would the tRNA anticodon bind during translation?

DNA strand transcribed

mRNA codon that tRNA anticodon binds to

DNA strand 1

second

DNA strand 2

second

DNA strand 1

third

DNA strand 2

third

[Maximum number: 1]

The diagram shows the translation of a mRNA molecule.

Question image

A tRNA molecule with anticodon CAG carries the amino acid phenylalanine. Which codon of mRNA will the tRNA join?

A

CTG

B

CAG

C

GTC

D

GUC

[Maximum number: 1]

The base sequences of a short section of DNA are shown, together with mRNA that has been transcribed from it and one of the tRNA anticodons that could be used to translate the mRNA.

DNA strand 1 A-C-G-G-C-A-T-T-A-G-C-T-A tRNA anticodon U-U-A

DNA strand 2 T-G-C-C-G-T-A-A-T-C-G-A-T mRNA U-G-C-C-G-U-A-A-U-C-G-A-U

Which strand of DNA is transcribed and to which codon in the mRNA would the tRNA anticodon bind during translation?

DNA strand transcribed

mRNA codon that tRNA anticodon binds to

DNA strand 1

second

DNA strand 2

second

DNA strand 1

third

DNA strand 2

third

[Maximum number: 1]

A DNA triplet on the strand that is transcribed has the bases TAG. Which anticodon on tRNA is used in translation?

A

AUC

B

UAG

C

TAG

D

ATC

[Maximum number: 6]

The structure of a transfer RNA (tRNA) molecule is shown in the diagram. The attached amino acid, which is aspartic acid, is indicated by the arrow.

Question image
(a)

Deduce the function of bases CUG.

[ 1 ]
(b)

Explain how living organisms ensure that the amino acid linked to this tRNA molecule is always aspartic acid.

[ 2 ]
(c)

During translation, three binding sites for tRNA molecules are used. Outline how each of these binding sites is used.

[ 3 ]
(a)

Label the parts of the DNA diagram indicated by I, II, III and IV.

Question image
[ 2 ]
(b)
(i)

State one role of nucleosomes in eukaryotic cells.

[ 1 ]
(ii)

Outline how Hershey and Chase's experiment provided evidence for DNA as the genetic material.

[ 3 ]
(iii)

State one function for a region of DNA that does not code for proteins.

[ 1 ]
(c)

Outline the role of the following in translation.

[ 3 ]
(i)

A-site of ribosomes

[ 1 ]
(ii)

tRNA activating enzymes

[ 2 ]
[Maximum number: 1]

The mRNA codon UAC codes for the amino acid tyrosine. Which tRNA carries tyrosine?

A
Question image
B
Question image
C
Question image
D
Question image
[Maximum number: 1]

This DNA sequence was used to synthesize a polypeptide.

Table

Which are the bases of the tRNA (anticodons)?

A

TAC TGA

B

∪AC∪GA\cup A C \cup G A

C

AUG ACU

D

ATG ACT

[Maximum number: 15]

DNA research, involving biotechnology, has led to benefits for society but has given rise to some controversy.

(a)

Outline how translation depends on complementary base pairing.

[ 3 ]
(b)

Describe the polymerase chain reaction (PCR), including the role of Taq DNA polymerase.

[ 4 ]
(c)

Explain benefits and risks of using genetically modified crops for the environment and also for human health.

[ 8 ]
0