Which of the following are correct statements about nucleosomes?
|
I. |
They contain histone proteins |
|
II. |
They help supercoil the DNA to form a compact structure |
|
III. |
They are found in both eukaryotes and prokaryotes |
|
IV. |
They consist of both DNA and chromatin |
I only
I and II
I, II and III
I, II and IV
When DNA polymerase adds a new nucleotide to a growing DNA strand, which part of the last nucleotide does it form a bond with?
Nitrogenous base
5’ phosphate group of a pentose sugar
1’ Carbon of a pentose sugar
3’ -OH group of a pentose sugar
Okazaki fragments are short sections of DNA formed during DNA replication.
Which of the following statements correctly describes why they form?
To help the DNA helix unwind
To enable replication of the leading strand
To act as a template for DNA polymerase
To enable replication of the lagging strand
What is the correct sequence of events during DNA replication?
|
first |
→ |
→ |
→ |
last |
|
| A |
I |
II |
III |
IV |
V |
| B |
II |
I |
III |
V |
IV |
| C |
I |
II |
V |
III |
IV |
| D |
II |
III |
IV |
V |
I |
The majority of the eukaryotic genome contains non-coding regions of DNA.
Which of the following are functions of non-coding DNA?
|
I. |
Code for functional RNA molecules |
|
II. |
Regulate gene expression |
|
III. |
Allow alternative proteins to be expressed from a gene |
|
IV. |
Act as telomeres |
I and II
II and III
I, II and III
I, II, III and IV
The shaded boxes in the diagram below (left) indicate Variable Number Tandem Repeats (VNTR) from three different loci that were amplified (via PCR) from DNA found at a crime scene. The diagram on the right shows DNA profiles of fragments amplified from the VNTR regions of four suspects. 
Which of these suspects was most likely at the crime scene?
The dideoxy chain-termination method of DNA sequencing developed by Fredrick Sanger uses dideoxynucleotides. These modified nucleotides lack a 3’-hydroxyl group.
Which of the following best describes the effect of lacking a 3’-hydroxyl group.
It allows the dideoxynucleotide to be labelled with a radioactive or fluorescent tag
It increases the efficiency of the sequencing reactions
The dideoxynucleotide cannot form a covalent bond with an incoming nucleotide
It prevents a thymine base from being incorporated into the developing DNA strand - which terminates the strand
In the 1950s, Hershey and Chase demonstrated that DNA, not protein, is a factor of heredity responsible for carrying genetic information from one generation to another. They used viruses that were labelled with either radioactive sulphur (35S) or radioactive phosphorus (32P) to infect bacteria.
Which of these statements correctly describes the results of their experiment?
Only bacteria infected by 32P labelled viruses were shown to be radioactive
32P was only detected in the supernatant
Only bacteria infected by 35S labelled viruses were shown to be radioactive
35S was detected in the pellet after centrifugation
Rosalind Franklin’s X-ray diffraction investigations provided crucial evidence that DNA was a double helix - this was instrumental to Crick and Watson developing their model of the structure of DNA.
Which statements about the structure of DNA were not answered by Franklin’s work?
The distance between nucleotides
The arrangement of the nitrogenous bases
The pitch of the helix
Phosphates were located on the outside of the molecule
Molecular visualisation software can be used to look at the three-dimensional structure of complex macromolecules such as the nucleosome.
Which of the following statements about molecular visualisation software are correct?
|
I. |
Can help relate structure to chemical or biological behaviour. |
|
II. |
Can support the design of pharmaceutically active compounds. |
|
III. |
Can be used to study the interactions between proteins. |
|
IV. |
Is primarily used to identify if a DNA sequence encodes for a gene. |
I and II
I, II and III
I and IV
I, II, III and IV
