WorksheetsIB Bio 2.7,2.6,7.1,7.2,7.3
Total questions: 99
Worksheet time: 2hrs 33mins
What is formed during transcription?
RNA strand complementary to DNA strand, formed by RNA polymerase
DNA strand complementary to DNA strand, formed by DNA polymerase
RNA strand complementary to RNA strand, formed by DNA polymerase
DNA strand complementary to RNA strand, formed by RNA polymerase
Research has shown that the genetic code is not entirely universal. Which research finding has shown this?
Some amino acids are coded for by more than one codon.
There are differences between the base sequences of genes in different species.
In some organisms the genetic code for mitochondria differs from the genetic code for the nucleus.
Some codons code for the addition of an amino acid and some code for the termination of translation.
This is a sequence of nucleotides from a section of mRNA.
AUGAAACGCACGCAG
From which DNA sequence has it been transcribed?
ATGAAACGCACGCAG
UACUUUGCGUGCGAC
TACUUUGCGTGCGTC
TACTTTGCGTGCGTC
What is a codon?
A sequence of nucleotides on rRNA that corresponds to an amino acid
A sequence of nucleotides on mRNA that corresponds to an amino acid
A sequence of nucleotides on tRNA that corresponds to an amino acid
A sequence of nucleotides on DNA that corresponds to an amino acid
The graph below shows the effect of temperature on the separation of the strands in DNA to form single strands. The temperature at which 50% of the DNA is single-stranded is called the melting temperature (TM). What do the results show?
When the temperature reaches 85°C there are no more double-stranded DNA molecules.
When the temperature reaches 85°C the DNA strands start separating rapidly.
A TM of 85°C means that DNA is not stable at room temperature (25°C).
The separation of the DNA strands is directly proportional to the increase in temperature.
What will be the sequence on the mRNA molecule that is produced when the DNA base sequence ACTGATGCC is transcribed?
ACTGATGCC
ACUGAUGCC
TGACTACGG
UGACUACGG
The table shows the genetic code. Which mRNA could code for the sequence Met-Ser-Leu-Arg-Phe?
AUG UCA UCG UGG UUU
AUG UCC ACC AGA UUC
AUG UCU CCC AGA UUU
AUG UCG CUG AGG UUC
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
How is the information in the genetic code used?
To predict the genotype of gametes
To distinguish prokaryotic genomes from eukaryotic genomes
To deduce phenotypes in pedigree charts
To translate mRNA into polypeptides
What sequence of processes is carried out by the structure labelled X during translation?
Combining with an amino acid and then binding to an anticodon
Binding to an anticodon and then combining with an amino acid
Binding to a codon and then combining with an amino acid
Combining with an amino acid and then binding to a codon
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 sequence of bases and amino acids could be produced by transcription and translation of the DNA molecule shown?
A.
B.
C.
D.
What is replicated by a semi-conservative process?
Messenger RNA (mRNA) only
Messenger RNA (mRNA) and transfer RNA (tRNA) only
Messenger RNA (mRNA), transfer RNA (tRNA) and DNA only
DNA only
What enables bacteria to produce human growth hormone?
DNA replication is semi-conservative.
The polymerase chain reaction can be used.
They need the hormone for growth.
The genetic code is universal.
Meselson and Stahl conducted experiments using the isotopes 14N and 15N which showed that DNA replication is semi-conservative. What would they have observed about the distribution of isotopes in the DNA after one round of replication if DNA replication was conservative rather than semi-conservative?
Only 14N DNA
Only 15N DNA
All DNA half 14N and half 15N
Half the DNA with only 14N and half with only 15N
What occurs during DNA replication?
DNA polymerase separates the two DNA strands.
DNA molecules containing nucleotides from the original molecule are produced.
Adenine forms a base pair with either thymine or uracil.
New bases attach to the original sugar-phosphate backbone.
What occurs during DNA replication?
DNA polymerase separates the two DNA strands.
DNA molecules containing nucleotides from the original molecule are produced.
Adenine forms a base pair with either thymine or uracil.
New bases attach to the original sugar-phosphate backbone.
On which molecule is a codon found?
DNA
mRNA
tRNA
rRNA
Which sequence represents the order of events in protein synthesis?
A.
B.
C.
D.
The diagram shows the translation of a mRNA molecule. A tRNA molecule with anticodon CAG carries the amino acid phenylalanine. Which codon of mRNA will the tRNA join?
CTG
CAG
GTC
GUC
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
What is required to replicate DNA?
Temperature of 37 °C
Free nucleotides carrying A, C, G and T bases
Plasmids
Endonuclease
Which of the following are involved in both replication and transcription?
DNA only
DNA and RNA
DNA and ribosomes
DNA, RNA and ribosomes
What happens during translation?
Copying of DNA to produce DNA
Copying of DNA to produce tRNA
Polypeptide synthesis
A base substitution in a gene has changed a codon. Which of these consequences could result from a base substitution in a codon?
I. Another amino acid will be incorporated in the protein
II. A stop codon is generated
III. The same protein will be synthesized
I only
I and II only
I and III only
I, II and III
A strand of mRNA consists of the following nucleotides:
AUUCUGGCUA
Which of the following represents the non-transcribed (sense) strand of the DNA?
TAAGACCGAT
ATTCTGGCTA
UAAGACCAU
AUUCUGGCUA
The table below shows the codons that determine different amino acids in protein translation. What is the sequence of the amino acids that is being translated from the following mRNA sequence?
5′ AUGGGUGCUUAUUGGUAA 3′
Met-Pro-Arg-Ile-Thr
Met-Cys-Ser-Tyr-Trp
Met-Gly-Ala-Tyr-Trp
Met-Gly-Tyr-Ala-Thr
What principle is necessary to prevent mutation of DNA during replication?
Base pairing is complementary.
One gene codes for one polypeptide.
Substrates are specific to enzymes.
The genetic code is universal.
Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is based on DNA sequences and the cladogram on the right is based on comparing protein sequences. What is the reason that cladograms based on DNA sequences are more reliable predictors of the phylogenetic relationship of species than cladograms based on protein sequences?
Amino acids are not as chemically stable as DNA nucleotides.
Several different triplets of bases can code for the same amino acid.
DNA mutates but amino acids do not.
There are 20 different amino acids but only 4 nucleotides.
For which discovery about DNA do Watson and Crick receive credit?
DNA is the molecule that genes are made of...
Phosphate–pentose bonding along the nucleotide backbone is covalent.
The amount of adenine equals the amount of thymine in an organism.
The shape of DNA is a double helix.
What is a similarity between DNA and RNA?
Both are polymers of nucleotides.
Both contain adenine, cytosine and thymine.
Both are composed of antiparallel strands.
Both contain ribose sugar.
Which sequence shows increasing relative size?
A.
B.
C.
D.
The image shows a DNA nucleotide. Which correctly identifies the parts labelled I and II?
I Base:
II Phosphate
I Deoxyribose:
II Base
I Ribose:
II Uracil
I Ribose:
II Adenine
The diagram shows a dinucleotide. Which type of bond is identified by the arrow?
Phosphate
Covalent
Hydrogen
Peptide
What links the pairs of complementary bases in a DNA double helix?
Covalent bonds
Ionic bonds
Hydrogen bonds
Peptide bonds
The percentage of thymine in the DNA of an organism is approximately 30 %. What is the percentage of guanine?
70 %
20 %
30 %
40 %
Which of the following are connected by hydrogen bonds?
Hydrogen to oxygen within a molecule of water
Base to sugar in a DNA molecule
Phosphate to sugar in a DNA molecule
Hydrogen to oxygen between two different molecules of water
The following diagram shows a short stretch of DNA. What bases are indicated by labels Y and Z?
Y thymine:
Z adenine
Y uracil:
Z guanine
Y thymine:
Z guanine
Y uracil:
Z adenine
Which molecules form the nucleotide marked in the diagram?
phosphate, deoxyribose and nitrogenous base
phosphorus, deoxyribose and guanosine
phosphorus, ribose and nitrogenous base
phosphate, ribose and guanine
This question refers to the following diagram of DNA. What does the structure labelled X represent?
Hydrogen bond
Covalent bond
Phosphate
Base
This question refers to the following diagram of DNA. What does the structure labelled Y represent?
Ribose
Guanine
Thymine
Deoxyribose
What usually distinguishes DNA from RNA?
A.
B.
C.
D.
Organisms can be genetically modified to produce the human blood clotting factor IX. What characteristic of the genetic code makes this possible?
It is conservative.
It is complementary.
It is degenerate.
It is universal
The base sequence of a fragment of DNA is:
ACC GTG CAG GAT
What is the base sequence on the messenger RNA (mRNA) molecule transcribed from it?
TGG CAC GTC CTA
UGG CTC GUC CUT
TGG CUC GTC CTU
UGG CAC GUC CUA
What type of bond is labelled X?
Ionic
Covalent
Peptide
Hydrogen
In the model of the DNA molecule shown below, which arrows point to covalent bonds?
I, II and III only
I, III and IV only
II, III and IV only
I, II and IV only
If 15 % of a sample of DNA is thymine, what percentage of the DNA is guanine?
15 %
35 %
30 %
It cannot be determined from the information given.
This question refers to the following DNA diagram. Which points to the 3′ end of a strand of DNA?
I
III
II
IV
This question refers to the following DNA diagram. What type of bond does Z represent?
Covalent bond
Peptide bond
Hydrogen bond
Semi-conservative bond
Organisms can be genetically modified to produce the human blood clotting factor IX. What characteristic of the genetic code makes this possible?
It is conservative.
It is complementary.
It is degenerate.
It is universal.
The base sequence of a fragment of DNA is:
ACC GTG CAG GAT
What is the base sequence on the messenger RNA (mRNA) molecule transcribed from it?
TGG CAC GTC CTA
UGG CTC GUC CUT
TGG CUC GTC CTU
UGG CAC GUC CUA
What type of bond is labelled X?
Ionic
Covalent
Peptide
Hydrogen
In the model of the DNA molecule shown below, which arrows point to covalent bonds?
I, II and III only
I, III and IV only
II, III and IV only
I, II and IV only
If 15 % of a sample of DNA is thymine, what percentage of the DNA is guanine?
15 %
35 %
30 %
It cannot be determined from the information given.
This question refers to the following DNA diagram. Which points to the 3′ end of a strand of DNA?
I
III
II
IV
What is correct for the DNA double helix?
Deoxyribose bonds to a… phosphate and a base
Hydrogen bonds form the bond between the… phosphates and the bases
Complementary base pairing between… adenine and uracil
Deoxyribose bonds to a… deoxyribose and a phosphate
Hydrogen bonds form the bond between the… deoxyribose molecules
Complementary base pairing between… thymine and guanine
Deoxyribose bonds to a… base and a deoxyribose
Hydrogen bonds form the bond between the… phosphate and the deoxyribose
Complementary base pairing between… adenine and thymine
Deoxyribose bonds to a… base and a phosphate
Hydrogen bonds form the bond between the… bases
Complementary base pairing between… cytosine and guanine
The diagram below represents part of the DNA molecule. What are the parts labelled I, II and III?
I: hydrogen bond
II: base
III: deoxyribose
I: covalent bond
II: base
III: deoxyribose
I: hydrogen bond
II: deoxyribose
III: phosphate group
I: covalent bond
II: deoxyribose
III: phosphate group
The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive system. The graph shows the percentage of samples in which this bacterium showed resistance to six antibiotics over a period of ten years. What is a possible explanation for the total percentage resistance being larger than 100% in 2010?
People do not take the antibiotics as prescribed.
There was an epidemic of Neisseria gonorrhoeae in that year.
More people have been sampled in that year.
Some bacteria are resistant to more than one antibiotic.
The diagram shows how pre-mRNA is processed into mature mRNA. Which structures are indicated by the letters W and X?
W: Exon
X: Poly-A tail
W: Intron
X: Exon
W: Poly-A tail
X: Exon
W: Exon
X: Intron
How does DNA replicate?
The deoxyribose of a free nucleotide is linked to the phosphate of the last nucleotide in the chain.
Nucleotides are linked in a 3′ to 5′ direction and the new strands are anti-parallel to the template strands.
The phosphate of a free nucleotide is linked to the deoxyribose of the last nucleotide in the chain.
Nucleotides are linked in a 5′ to 3′ direction and the new strands are parallel to the template strands.
What are Okazaki fragments?
Short lengths of RNA primase attached to the DNA during replication
Nucleotides added by DNA polymerase I in the same direction as the replication fork
Short sections of DNA formed during DNA replication
Sections of RNA removed by DNA polymerase III and replaced with DNA
What does a nucleosome consist of?
DNA and histones
Chromatin and nucleotides
DNA and chromatin
Mature RNA and histones
What is a nucleosome?
A region in a prokaryotic cell where DNA is found
A ribosome of a prokaryotic cell
A DNA molecule wrapped around histone proteins
A molecule consisting of a sugar, a base and a phosphate
What are the fundamental packaging units of eukaryotic chromosomes?
Nucleosomes
Histones
Centromeres
Nucleoids
Which of the following chemicals is a component of eukaryotic chromosomes?
Protein
Fatty acid
Triglyceride
RNA
What is the reason for Okazaki fragments being formed during DNA replication?
To enable replication of the 3′ → 5′ (lagging) strand
To initiate replication on the 5′ → 3′ (leading) strand
To form the template for the RNA primers
To help the DNA helicase unwinding the DNA helix 27
Which of the following forms the nucleosome?
DNA and histone molecules
RNA and histone molecules
DNA only
Histone molecules only
What happens during the formation of Okazaki fragments?
DNA polymerase III adds nucleotides in the 3′→ 5′ direction.
DNA polymerase I adds nucleotides in the 5′→ 3′ direction.
DNA polymerase III adds nucleotides in the 5′→ 3′ direction.
RNA polymerase adds nucleotides in the 3′→ 5′ direction.
The diagram below shows part of a DNA molecule that is being replicated. Where would DNA polymerase link the next nucleotide during replication?
I
III
II
IV
After which process are introns removed?
Replication
Translation
Transcription
Translocation
Which structure found in eukaryotes has a single membrane?
Nucleus
Chloroplast
Lysosome
Mitochondrion
Which is a valid comparison between prokaryotic and eukaryotic DNA?
A.
B.
C.
D.
Which letter (A–D) indicates where a new nucleotide would attach?
A.
B.
C.
D.
In which process(es) do nucleosomes play a role in eukaryotes?
I. tRNA activation
II. Transcription regulation
III. DNA supercoiling
I only
II and III only
II only
I, II and III
Very soon after fertilization, parental epigenetic methylation is reversed in the DNA.Later, tissue-specific epigenetic modifications are made to the embryonic DNA. The graph follows the degree of methylation from different sources during embryonic development. According to the graph, what are the changes in DNA methylation during embryonic development?
Only the paternal DNA becomes demethylated.
The methylation patterns of the parents’ DNA are erased before fertilization.
The maternal DNA becomes demethylated first
The methylation patterns of both parents are erased after fertilization.
What is a feature of transcription?
Both strands of a DNA molecule act as a template for mRNA.
RNA polymerase binds to the promoter region.
Nucleoside triphosphates become nucleotides by losing three phosphates.
The sense strand acts as a template for mRNA.
What are introns?
Sequences of nucleotides that are removed to form mature RNA in eukaryotes
Sequences that remain in mature RNA after exons have been removed
Sequences of nucleotides that are removed to form mature RNA in prokaryotes
Small pieces of circular DNA that are found in prokaryotes
What makes up eukaryotic RNA immediately after transcription?
Exons, introns and primers
Introns only
Exons and introns
Exons only
The sequence of nucleotides in a section of RNA is: GCCAUACGAUCG
What is the base sequence of the DNA sense strand?
CGGUAUGCUAGC
CGGTATGCTAGC
GCCATACGATCG
GCCAUACGAUCG
Which statement applies to transcription in eukaryotic cells but not to prokaryotic cells?
RNA polymerase transcribes the antisense strand of DNA to produce a strand of RNA.
Transcription takes place in the cell nucleus.
During transcription, uracil replaces thymine in RNA.
Initiation of transcription requires a promoter sequence of DNA.
The antisense strand on the DNA molecule coding for three codons of a gene is
TATCGCACG
What are the anticodons of the three tRNA molecules that correspond to this sequence?
UAU, CGC and ACG
AUA, GCG and UGC
ATA, GCG and TGC
TAT, CGC and ACG
What is the relationship between enzymes and DNA?
Enzymes contain the code for DNA.
Enzymes act on DNA during translation.
Both enzymes and DNA have similar shapes.
The structure of enzymes is determined by DNA.
What is removed during the formation of mature RNA in eukaryotes?
Exons
Codons
Introns
Nucleosomes
The antisense strand of a DNA molecule has the sequence TACCCGATC. What would be the resulting mRNA strand sequence?
TACCCGATC
UACCCGAUC
ATGGGCTAG
AUGGGCUAG
Some regions of DNA do not code for the production of proteins. What are these regions of DNA used as?
They have no known function and are recycled to provide nucleotides
Telomeres and coding for production of tRNA
Gene regulation and coding for production of enzymes used in translation
Introns and coding for production of structural proteins
Scientists have heated a solution containing the protein albumin and measured its relative alpha helix content, shown on the graph. What does the zone labelled X indicate?
Rapid increase in beta pleated sheets
Rapid formation of hydrogen bonds
Rapid increase in denatured protein molecules
Rapid decrease in peptide bonds
This image is taken from a visualization of a eukaryotic ribosome. The arrows show the direction of movement of mRNA. Which letter represents a tRNA exiting from the E site?
A.
B.
C.
D.
Which types of interactions are found in a part of a protein with secondary but not tertiary structure?
I. Hydrogen bonds
II. Disulphide bridges
III. Ionic bonds
I only
I and II only
II and III only
I, II and III
Variations in the types of antibodies are produced by mRNA splicing. What is an advantage of this process?
Reduces the size of mRNA required for the translation of antibodies
Increases the number of different antibodies that can be synthesized
Ensures that one gene codes for one antibody
Speeds up transcription of antibodies
What does post-transcriptional modification of eukaryotic mRNA include?
I. Introns are removed from mRNA.
II. Exons are joined together to form mature mRNA.
III. A 5′ cap and 3′ poly-A tail are added to mRNA.
I only
I and III only
II and III only
I, II and III
Where does a tRNA-activating enzyme attach the appropriate amino acid to the tRNA molecule?
A.
B.
C.
D.
The image represents a model of the protein transthyretin. Which level of structure is indicated by X on the image?
Primary
Secondary
Tertiary
Quaternary
The image shows the structure of hemoglobin. What determines the primary structure of hemoglobin?
Genetic information
Hydrogen bonding
Four polypeptide chains
Side chain interactions
The following diagram shows a ribosome during translation. What describes the specific stage of translation?
Initiation
Elongation
Termination
Translocation
Which best describes the tertiary structure of a protein?
The interaction of polypeptide subunits and prosthetic groups
Interactions forming hydrogen bonds between the amino acids
The sequence of amino acids in the polypeptide chain
Which cell component synthesizes actin and myosin?
Free ribosomes
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Nuclear membrane
The diagram is a three-dimensional molecular model of a protein. Which bonds stabilize the shape of the area labelled X?
Covalent bonds between adjacent amino acids
Hydrogen bonds between N–H and C=O groups of amino acids
Hydrophobic interactions between R groups of amino acids
Disulphide bridges between cysteine molecules
The diagram shows the cross section of a plasma membrane. What is found in area X?
Glycolipid
Glycoprotein
Polar amino acid
Non-polar amino acid
What is the distinction between highly repetitive DNA sequences and single-copy genes?
The highly repetitive sequences have greater amounts of guanine.
The highly repetitive sequences have greater amounts of cytosine.
The highly repetitive sequences are not transcribed.
The highly repetitive sequences are not replicated.
