MCQs

Question 1

The rules used to determine the link between the nucleotide sequence of a gene and the amino acid sequence of the protein specified by that gene is referred to as:  
A. secondary structure guidelines  
B. R group rules  
C. codon assignments steps  
D. the genetic code  
E. Chargaff’s rules

Answer 1

D. the genetic code

Question 2

Which of the following is incorrect?
A. the amino terminus of a protein corresponds to the 3′ end of a gene
B. a codon always contains a triplet of nucleotides
C. the order of nucleotides in a prokaryotic gene correlates precisely with the order of amino acids in the corresponding protein
D. a deletion of one or two nucleotides in the coding region of a gene will disrupt the codons downstream of the deletion and give rise to a non-functional protein
E. through wobble, it is possible for one tRNA to read two or possibly three codons.

Answer 2

A. the amino terminus of a protein corresponds to the 3′ end of a gene

Question 3

In terms of actual gene coding sequences, how much bigger is the human genome than the Escherichia coli genome?  
A. 10,000 x  
B. 5,000 x  
C. 1,000 x  
D. 500 x  
E. 50 x.

Answer 3

E. 50 x.

Question 4

In the context of prokaryotic gene expression, which of the following is the most appropriate definition of an operator?
A. a cluster of genes that are regulated by a single promotor
B. a DNA-binding protein that regulates gene expression
C. a non-coding regulatory DNA sequence that is bound by RNA polymerase
D. a non-coding regulatory DNA sequence that is bound by a repressor protein
E. a section of DNA transcribed but not translated.

Answer 4

D. a non-coding regulatory DNA sequence that is bound by a repressor protein

Question 5

A frameshift mutation could be caused by a:
A. a transitional base substitution
B. a transversional base substitution
C. a deletion of 3 base pairs
D. an insertion of 3 base pairs
E. a deletion or insertion of 1 or 2 base pairs.

Answer 5

E. a deletion or insertion of 1 or 2 base pairs.

Question 6

Bacteriophage mediated gene transfer amongst bacteria is known as:  
A. transformation  
B. transduction  
C. translocation  
D. transcription  
E. translation.

Answer 6

B. transduction

Question 7

In female mammals, one X chromosome is largely inactivated. The inactivated X chromosome has:
A. higher levels of acetylation of histone proteins
B. lower levels of acetylation of histone proteins
C. a lack of associated histone proteins
D. lower levels of DNA methylation
E. higher levels of DNA methylation.

Answer 7

E. higher levels of DNA methylation.

Question 8

Eukaryote gene enhancer sequences are:
A. located either side of a gene, at some distance from a gene, or even within a gene
B. located downstream of the genes which they regulate
C. located upstream of the genes which they regulate
D. situated at a fixed distance from the site where transcription is initiated
E. able only to affect the expression of a single specific gene.

Answer 8

A. located either side of a gene, at some distance from a gene, or even within a gene

Question 9

Changes in chromatin organisation (chromatin remodelling) may be required for various processes in eukaryotes. Which?
A. DNA repair, replication, recombination, and transcription
B. DNA repair, replication, and recombination, but not transcription
C. DNA repair and replication, but not recombination or transcription
D. DNA repair, but not replication, recombination, or transcription
E. DNA transcription only

Answer 9

A. DNA repair, replication, recombination, and transcription

Question 10

The anterior-posterior axis in the early Drosophila embryo is established by concentration gradients of which proteins?  
A. NOS and BCD proteins  
B. NOS and HB-M proteins  
C. BCD and HB-M proteins  
D. BCD and CACT proteins  
E. HB-M and CACT proteins.

Answer 10

C. BCD and HB-M proteins

Question 11

In humans, HOX genes are found:
A. spread throughout the genome and located on most chromosomes
B. organised in four clusters located on four different chromosomes
C. organised in four clusters, two clusters located on each of two different chromosomes
D. closely linked together in a cluster on a single chromosome
E. spread throughout the length of a single chromosome.

Answer 11

B. organised in four clusters located on four different chromosomes

Question 12

12.  Mutations can occur at the level of:  
A. DNA bases  
B. an individual gene  
C. chromosomes  
D. the whole genome  
E. all of the above.

Answer 12

E. all of the above.

Question 13

13. Apoptosis or programmed cell death occurs:
    A. at single cell level
    B. in a group of cells
    C. either at a single cell level or in a group of cells
    D. at tissue level
    E. at the organ level.

Answer 13

A. at single cell level

Question 14

DNA repair using a homologous recombination (HR) process takes place:
A. shortly after S and G2 phases of the cell cycle
B. only in the S phase of the cell cycle
C. in the mitotic phase of the cell cycle
D. in the G1 phase of the cell cycle
E. at any stage of the cell cycle.

Answer 14

A. shortly after S and G2 phases of the cell cycle

Question 15

Xeroderma pigmentosum :
A. is an autosomal recessive disease
B. individuals are sensitive to sun/UV light
C. individuals are deficient in DNA repair process
D. all of the above
E. none of the above.

Answer 15

D. all of the above

Question 16

Ultraviolet (UV) radiation B and C induces:  
A. purine dimers  
B. pyrimidine dimers  
C. 6-4 photoproducts (6-4PP)  
D. both pyrimidine dimers and 6-4PP  
E. neither pyrimidine dimers and 6-4PP.

Answer 16

D. both pyrimidine dimers and 6-4PP

Question 17

For biomonitoring purposes, single cell gel electrophoresis or comet assay is used to evaluate:
A. chromosomal aberrations and aneuploidy
B. mutations in specific genes
C. DNA strand breaks
D. sister chromatid exchanges (SCEs)
E. DNA adducts.

Answer 17

C. DNA strand breaks

Question 18

Chromosomal aberrations are biomarkers of:  
A. exposure  
B. effects  
C. susceptibility  
D. all of the above  
E. this is not a biomarker.

Answer 18

D. all of the above

Question 19

A DNA replicon molecule used to accept inserts of DNA for gene cloning purposes is known as a cloning vector, or a cloning:  
A. vectron  
B. vehicle  
C. vecsert  
D. vectrum  
E. vecmid.

Answer 19

B. vehicle

Question 20

The biological role of restriction enzymes is to:
A. degrade foreign DNA that enters a bacterium
B. restrict the damage to DNA by UV light
C. make bacteria resistant to antibiotics
D. restrict the size of DNA in bacteria
E. aid recombinant DNA research.

Answer 20

A. degrade foreign DNA that enters a bacterium

Question 21

A gene created by joining gene segments from two different genes is known as a:  
A. recombinant gene  
B. make-shift gene  
C. chimaeric gene  
D. conjoined gene  
E. mutant gene.

Answer 21

C. chimaeric gene

Question 22

A Shine Dalgarno sequence is introduced in to many bacterial expression vectors to enhance:
A. transcription of cloned genes
B. bacterial growth
C. binding of mRNA from cloned genes to bacterial ribosomes
D. stabilise cloned proteins
E. binding of bacterial RNA polymerase to the promotor of a cloned gene.

Answer 22

C. binding of mRNA from cloned genes to bacterial ribosomes

Question 23

Which of the following yeast cloning vectors is not a plasmid?  
A. YIP  
B. YEP  
C. YCP  
D. YRP  
E. YAC.

Answer 23

E. YAC

Question 24

The abbreviation RT-PCR stands for:
A. Real Time Polymerase Chain Reaction
B. Rotating Tube Polymerase Chain Reaction
C. Reverse Template Polymerase Chain Reaction
D. Reverse Transcription Polymerase Chain Reaction
E. Reverse Translation Polymerase Chain Reaction.

Answer 24

D. Reverse Transcription Polymerase Chain Reaction

Question 25

Why is insulin produced by genetically engineered Escherichia coli cells superior to insulin obtained from animal sources?
A. animal insulin has a shorter life span than insulin produced using recombinant DNA techniques
B. it contains human rather than animal sequences, reducing the chances of an allergic response.
C. animal insulin is more difficult to purify than is recombinantly produced insulin
D. recombinantly produced insulin has a much higher activity level
E. recombinantly produced insulin is easier to obtain than insulin from animals.

Answer 25

C. animal insulin is more difficult to purify than is recombinantly produced insulin

Question 26

Which of the following statements relating to genetic diversity in mammals is correct? Mammals are typically:
A. polymorphic at 10% of gene loci and heterozygous at 5%
B. polymorphic at 25% of gene loci and heterozygous at 5%
C. polymorphic at 25% of gene loci and heterozygous at 15%
D. polymorphic at 40% of gene loci and heterozygous at 5%
E. polymorphic at 40% of gene loci and heterozygous at 15%

Answer 26

B. polymorphic at 25% of gene loci and heterozygous at 5%

Question 27

Different types of genetic marker can be used to investigate levels of intraspecific diversity. Which of the following statements is true of human genetic diversity?
A. with Y chromosome markers more variation between populations is found than with mtDNA and autosomal markers
B. with mtDNA markers more variation between populations is found than with Y chromosome and autosomal markers
C. with autosomal markers more variation between populations is found than with mtDNA and Y chromosome markers
D. with mtDNA and Y chromosome markers more variation between populations is found than with autosomal markers
E. with autosomal and Y chromosome markers more variation between populations is found than with mtDNA markers.

Answer 27

D. with mtDNA and Y chromosome markers more variation between populations is found than with autosomal markers

Question 28

Fossil and archaeological evidence suggest that modern humans expanded out of Africa whenever the climate allowed.  However, it appears that only expansions after a certain date have contributed to modern human populations.  That date is:  
A. 100 KYA  
B. 80 KYA  
C. 60 KYA  
D. 40 KYA  
E. 20 KYA.

Answer 28

D. 40 KYA

Question 29

The effective population size (Ne) of the human mitochondrial genome compared to that of the nuclear genome is:  
A. 25%  
B. 50%  
C. the same  
D. 200%  
E. unknown.

Answer 29

A. 25%

Question 30

Which of the following statements about fixation coefficients is true?
A. humans, despite a worldwide distribution, exhibit low FST values
B. human FST values provide evidence to justify racial classifications
C. human FST values provide direct evidence of human migration patterns
D. none of the above
E. all of the above.

Answer 30

E. all of the above.