Vector Biology Multiple Choice Questions on “Vectors for Insects”.
1. Recombinant proteins are expressed in _____________
A. E.coli
B. Yeast
A. Animals
D. Fungi
Answer: C
Clarification: Vector systems are needed in biotechnology for cloning genes in animal cells, for the synthesis of recombinant proteins from genes that are not correctly expressed in E.coli or yeast.
2. What is gene therapy?
A. Technique of curing a disease
B. Introduction of a disease
A. Introduction of a gene in E.coli
D. Introduction of a gene in yeast
Answer: A
Clarification: Methods for cloning in humans are being sought by clinical molecular biologists attempting to devise techniques for gene therapy, in which a disease is treated by the introduction of cloned gene into the patient.
3. What is Drosophila Melanogaster?
A. Fruit fly
B. House fly
A. Damsel fly
D. Dragon fly
Answer: A
Clarification: Drosophila melanogaster is a popular model organism which is basically a fruit fly. It came into laboratory recognition with Morgan’s experiments.
4. When were the experiments with Drosophila Melanogaster first attempted?
A. 1910
B. 1810
A. 1710
D. 1610
Answer: A
Clarification: The potential of Drosophila Melanogaster was first recognized by geneticist Thomas Hunt Morgan, who is 1910 started to carry out genetic crosses between the flies.
5. Several genes constituting the genome of Drosophila are closely related to equivalent genes in mammals.
A. True
B. False
Answer: A
Clarification: The homeotic selector genes of Drosophila- the genes that control the overall body plan of the fly, are closely related to equivalent genes in mammals.
6. What is the P element?
A. Popular element
B. Transposon
A. Homeotic gene
D. Pressure inducing gene
Answer: B
Clarification: No plasmids are known in Drosophila and no viruses that infect the organism are used as vectors for it. Instead, cloning in Drosophila makes use of a transposon called the P element.
7. What is the approximate length of the P element?
A. Less than 1 kb
B. Less than 10 kb
A. Less than 20 kb
D. Less than 20 mb
Answer: B
Clarification: P element is a transposon found in the fruit fly Drosophila Melanogaster. Transposons are common in all organism, they are short pieces of DNA, usually less than 10 kb in length.
8. Transposons can move from one position to another in the ________ of a cell.
A. Nucleus
B. Chromosome
A. Cell membrane
D. Mitochondria
Answer: B
Clarification: Transposons, also known as jumping genes can change their positions from one location to the other in a chromosome. The transposon named P element found in Drosophila is 2.9 kb in size.
9. How many genes are contained in a P element?
A. 1
B. 2
A. 3
D. 4
Answer: C
Clarification: P elements found in the fruit fly Drosophila Melanogaster are actually the transposons residing in the chromosome of the organism. It contains three genes flanked by two unique regions on both the ends.
10. Which sequences flank the P element of the Drosophila?
A. Repeated
B. Interstitial
A. Inverted repeats
D. Random
Answer: C
Clarification: P elements, which are one of the several types of transposons found in Drosophila, are 2.9 kb in length and contain three genes flanked by short inverted repeat sequences.
11. What do the genes of the P element code for?
A. Amylase
B. Lactase
A. Transposase
D. Transcriptase
Answer: C
Clarification: P elements are used as cloning vectors in Drosophila, these
are 2.9 kb in length and contain three genes flanked by short inverted repeat sequences, the genes code for the enzyme transposase which carries out the transposition activity.
12. What is the function of flanking inverted repeats in a P element?
A. Maintaining homeostasis
B. Recognition sequence
A. Repression/induction activity
D. Operators
Answer: B
Clarification: The three genes present in the P element code for transposase enzyme and the repeat sequence on two ends act as recognition sequences that enable the enzyme to identify.
13. A P element can change position/ jump between a ________ and one of the fly’s chromosome.
A. Plasmid
B. Bacterial chromosome
A. Yeast chromosome
D. Another fly’s chromosome
Answer: A
Clarification: As well as moving from one site to another within a chromosome, P elements can also jump between chromosomes, or between a plasmid carrying a P element and one of the fly’s chromosomes.
14. The basic vector used for cloning in Drosophila is __________
A. Plasmid
B. Baculovirus
A. Culimovirus
D. YAC
Answer: A
Clarification: The vector is a plasmid that carries two P elements, one of which contains the insertion site for the DNA that will be cloned. The second P element has its inverted repeat sequences removed.
15. Baculovirus are vectors used for cloning in _____________
A. Mammals
B. Insects
A. Reptiles
D. Plants
Answer: B
Clarification: Baculovirus is important vectors that play an important role in gene cloning in insects other than Drosophila. Their main use is a production of recombinant proteins.