WorksheetsIB Biology HL Dna
Total questions: 23
Worksheet time: 46mins
Meselson and Stahl investigated DNA replication by first feeding bacteria with bases containing 15N (heavy), and then with bases containing 14N (light). The results are shown in the photographs.
From this information, what would be the composition of the DNA in generation 3?
There will be a single 14N band.
There will be a single 15N band and a single 14N band.
There will be a darker 14N band and a lighter hybrid band.
There will be a single 15N band, a single hybrid band and a single 14N band.
A short sequence of nucleotides reads GGACAGAGCGCAGACGA. In which type of molecule could this sequence be found?
DNA molecule only
RNA molecule only
Both in a DNA and an RNA molecule
In double-stranded DNA only
Which type of bond is identified by the arrow?
Phosphate
Hydrogen
Covalent
Peptide
What is required to replicate DNA?
Temperature of 37 °C
Free nucleotides carrying A, C, G and T bases
Plasmids
Endonuclease
Which points to the 3′ end of a strand of DNA?
I
II
III
IV
Which of the following statements is/are correct for DNA replication?
I. It occurs during interphase.
II. It is semi-conservative.
III. It is a stage in protein synthesis.
I only
II only
I and II only
I, II and III
Which enzyme catalyzes the elongation of the leading strand?
RNA polymerase
Helicase
DNA polymerase
Ligase
The percentage of thymine in the DNA of an organism is approximately 30 %. What is the percentage of guanine?
70 %
30 %
40 %
20 %
The image shows a DNA nucleotide.
Which correctly identifies the parts labelled I and II?
I phosphate; II base
I ribose; II uracil
I deoxyribose; II base
I ribose; II base
What is amplified using the polymerase chain reaction (PCR)?
Large amounts of RNA
Small amounts of DNA
Small amounts of protein
Large amounts of polymers
Which process is used in polymerase chain reaction (PCR)?
Transcription
Translation
Replication
Mutation
What does helicase do?
unwinds the DNA double helix
forms a sugar-phosphate backbone
breaks hydrogen bonds between basis
joins Okazaki fragments
What does ligase do?
unwinds the DNA double helix
forms a sugar-phosphate backbone
breaks hydrogen bonds between basis
joins Okazaki fragments
Which of these statements are true for PCR?
it amplifies a small sample of DNA
annealing is when the DNA is heated to separate the DNA strands
elongation is when DNA polymerase copies the DNA strands
DNA is heated to separate the 2 strands
What kind of bond joins DNA bases together?
covalent bonds
peptide bonds
hydrogen bonds
sugar-phosphate bond
What kind of bond joins nucleotides together?
covalent bonds
peptide bonds
hydrogen bonds
sugar-phosphate bond
Which are necessary to make DNA replication semi-conservative?
I. Separation of the strands by RNA polymerase
II. Complementary base pairing
III. Use of a pre-existing strand as a template
I and II only
I and III only
II and III only
I, II and III
What contribution did the X-ray diffraction conducted by Rosalind Franklin make to our understanding of DNA?
It identified DNA as the genetic material.
It indicated the helical shape of the molecule.
It showed that the DNA of eukaryotes was associated with histone proteins.
It showed that replication was a semi-conservative process.
Hershey and Chase used a bacteriophage (a virus that infects bacteria) to investigate the chemical nature of genes.
The sulphur in the protein and the phosphorus in the DNA of the bacteriophage were radioactively labelled. The data obtained after bacterial infection and centrifugation are shown in the table.
What did Hershey and Chase conclude from their experiment?
DNA was mainly outside the bacterial cells.
Viruses infect bacterial cells with proteins.
Viral DNA was found within the bacterial cells.
Neither protein nor DNA were chemicals making up genes in viruses.
Current understanding of DNA is an example of the accumulated discoveries of many scientists. Which scientists are credited with establishing that DNA is the genetic material?
Franklin and Wilkins
Watson and Crick
Meselson and Stahl
Hershey and Chase
What are the functions of DNA primase and DNA polymerase I in DNA replication?
A
B
C
D
Which letter (A–D) indicates where a new nucleotide would attach?
A
B
C
D
Which is a valid comparison between prokaryotic and eukaryotic DNA?
A
B
C
D
