Structure & Properties of Nucleoacids - Exam Questions

Question 1

An experiment by Griffith (1928) used pathogenic (S) and harmless (R) strains to infect cells. Which combination of living and dead strains gave evidence for a ‘transforming principle’?

Answer 1

Living R and dead S cells

Question 2

Protein can be specifically labelled with:

a. 35S
b. 32P
c. 15O
d. 3H
e. 15N

Answer 2

a. Proteins can be specifically labelled with 35S

Question 3

DNA can be specifically labelled with:

a. 35S
b. 32P
c. 15O
d. 3H
e. 15N

Answer 3

b. DNA can be specifically labelled with 32P

Question 4

Compared to RNA, DNA has:

a. an OH instead of an H on carbon 4 of the pentose
b. an H instead of an OH on carbon 4 of the pentose
c. an OH instead of an H on carbon 2 of the pentose
d. an H instead of an OH on carbon 2 of the pentose
e. an OH instead of an H on the carbon 3 of the pentose
f. an H instead of an OH on carbon 3 of the pentose.

Answer 4

d. DNA has an H instead of an OH on the carbon 2 of pentose compared to RNA.

Question 5

What is adenine?

Answer 5

Purine with an amino group and no carbonyl group.

Question 6

What is guanine?

Answer 6

2 ring structure with amino and carbonyl groups.

Question 7

What is thymine?

Answer 7

6-member ring with a methyl group

Question 8

What is uracil?

Answer 8

Pyrimidine with neither methyl nor amino groups

Question 9

What is cytosine?

Answer 9

Pyrimidine with amino group.

Question 10

A base attached to a pentose sugar is a..?

Answer 10

Nucleoside

Question 11

In the context of nucleic acids, G refers to..?

Answer 11

Guanosine

Question 12

In the context of nucleic acids, CDP refers to..?

Answer 12

Cytidine diphosphate

Question 13

In the context of nucleic acids, dA refers to..?

Answer 13

Deoxyadenosine

Question 14

In the context of nucleic acids, dGTP refers to..?

Answer 14

Deoxyguanosine triphosphate

Question 15

In the context of nucleic acids, cAMP refers to..

Answer 15

Cyclic adenosine monophosphate

Question 16

Nucleotide monomers are joined into a polynucleotide by which bond?

Answer 16

Phosphodiester bonds

Question 17

Franklin and Wilkins:

a. discovered DNA
b. determined that DNA was the heritable material.
c. constructed a model of DNA
d. conducted X-ray diffraction experiments on DNA
e. determined the role of the triplet codons in DNA

Answer 17

d. Franklin and Wilkins conducted X-ray diffraction experiments on DNA

Question 18

What is the number of nucleotides per turn in DNA?

Answer 18

10

Question 19

What are the number of hydrogen bonds between each base pairing?

Answer 19

A -T = 2 bonds

C - G = 3 bonds

Question 20

What is a nucleosome?

Answer 20

DNA wound around a histone

Question 21

What is the typical diameter of a DNA double helix?

Answer 21

2nm

Question 22

What is the typical diameter of the ‘beads on a string’ form of chromatin?

Answer 22

11nm

Question 23

What is the typical diameter of a packed chromatin fibre?

Answer 23

30nm

Question 24

What is the typical diameter of a condensed section of chromosome?

Answer 24

700nm

Question 25

What is the typical diameter of an entire mitotic chromosome?

Answer 25

1.4um

Question 26

What is the percentage of the genome that encodes proteins?

Answer 26

1.5%

Question 27

Approximate the number of chromosome pairs in the humans genome.

Answer 27

3x10^9

Question 28

Approximate the number of genes in the human genome

Answer 28

23,000

Question 29

What are introns?

Answer 29

Non coding DNA within genes

Question 30

Pre-mRNA contains a cap at one end, a tail at the other and…?

Answer 30

Exons and introns.

Question 31

Tandem repeats are formed in:

a. LINES
b. SINES
c. retroposons
d. satellite DNA
e. introns

Answer 31

d. Tandem repeats are forming in satellite DNA