MCQs Flashcards
1
Q
- Within a eukaryote gene sequence, introns are:
A. the sequence information that codes for a polypeptide
B. sequences not transcribed
C. sequences transcribed but not translated
D. sequences necessary for replication
E. sequences involved in DNA replication
A
C. sequences transcribed but not translated
2
Q
2. All polymerases make mistakes during nucleic acid replication, but the highest mutation rate due to replication errors are found in: A. prokaryotes B. RNA viruses C. DNA viruses D. eukaryotes E. prions.
A
B. RNA viruses
3
Q
3. During DNA replication, which enzyme joins Okazaki fragments together? A. DNA endonuclease B. DNA polymerase C. DNA ligase D. Taq 1 E. DNA gyrase.
A
C. DNA ligase
4
Q
4. Approximately how much of a bacterial genome actually codes for cellular components? Select one of the following. A. 10% B. 30% C. 50% D. 70% E. 90%
A
E. 90%
5
Q
5. At what frequency do enol or imino forms of nucleotides bases occur in living cells? A. 1 in 106 B. 1 in 105 C. 1 in 104 D. 1 in 103 E. 1 in 102.
A
E. 1 in 102
6
Q
- Which of the following statements describes modes of genetic transfer amongst the bacteria?
A. conjugation and translocation
B. transplantation and transformation
C. transplantation and transduction
D. conjugation, transduction, and transformation
E. transplantation, transduction, and transformation.
A
D. conjugation, transduction, and transformation
7
Q
- Bacterial gene expression is dependent on three main influences. Select from the following, which best describes those influences:
A. rates of transcription and translation, and gene copy number
B. rates of growth, mitosis and meiosis
C. rates of nutrient uptake, metabolism and removal of waste from the bacterium
D. rates of nucleotide, protein and fat synthesis
E. rates of energy production, carbohydrate synthesis and cell death.
A
A. rates of transcription and translation, and gene copy number
8
Q
- Which of the following statements about eukaryote gene enhancer sequences is correct?
A. enhancers can be either side of a gene, at some distance from a gene, or even within a gene
B. enhancers are located downstream of the genes which they regulate
C. enhancers are located upstream of the genes which they regulate
D. enhancers are always situated at a fixed distance from the site where transcription is initiated
E. an enhancer can only affect the expression of a single specific gene.
A
A. enhancers can be either side of a gene, at some distance from a gene, or even within a gene
9
Q
9. 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.
A
C. BCD and HB-M proteins
10
Q
- Hox genes in mammalian embryos are expressed to:
A. define segments in the developing somites (segmental units of the spinal column) and central nervous system
B. determine the development of the brain and central nervous system only
C. determine the development of the fore limbs only
D. determine the development of the hind limbs only
E. determine the anterior-posterior axis.
A
A. define segments in the developing somites (segmental units of the spinal column) and central nervous system
11
Q
11. Mutations can occur at the level of: A. DNA bases B. individual genes C. chromosomes D. the whole genome E. all of the above levels.
A
E. all of the above levels.
12
Q
- Fragile X-syndrome results from changes in the FMR-1 gene due to:
A. deletion of trinucleotide sequence, CGG
B. duplication of trinucleotide sequence, CGG
C. inversion of trinucleotide sequence, CGG
D. translocation of trinucleotide sequence, CGG
E. all the above.
A
B. duplication of trinucleotide sequence, CGG
13
Q
- DNA repair using 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 mitotic phase of the cell cycle
D. in G1 phase of the cell cycle
E. at any phase of the cell cycle.
A
A. shortly after S and G2 phases of the cell cycle
14
Q
- The p53 gene is:
A. a tumour suppressor gene
B. known as ‘guardian of the genome’
C. mutated in approximately 60% of cancers
D. involved in a check point at the G1/ S border
E. all the above.
A
E. all the above.
15
Q
- For biomonitoring purposes, singe 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.
A
C. DNA strand breaks