Biology Multiple Choice Questions on “Biotechnology Applications – Pest Resistant Plants – 1”.
1. Which nematode infects the roots of tobacco plants?
a) Meloidogyne incognitia
b) Ditylenchus dipsaci
c) Xiphinema index
d) Nacobbus aberrans
Answer: a
Clarification: Meloidogyne incognitia is the nematode that infects the roots of tobacco plants. It is also known as ‘root-knot nematode’. It is a plant-parasitic nematode. It affects both monocots as well as dicot plants.
2. Which one is the method of cellular defense in animals and plants?
a) Recombinant DNA technology
b) RNA interference
c) Immune response
d) Mutation
Answer: b
Clarification: RNA interference is one of the cellular defense mechanisms found in animals and plants. It defends against viruses and transposable elements. In this method, short RNA stretches are used (20-30 nucleotides).
3. RNAi stands for ______
a) RNA intersection
b) RNA insertion
c) RNA intercom
d) RNA interference
Answer: d
Clarification: RNAi stands for RNA interference. It is a series of processes in which short RNA sequences are used to recognize and manipulate complementary nucleic acids. These short RNA sequences consist of 20-30 nucleotides. It protects against viruses and transposable elements.
4. _________ is mobile genetic elements.
a) Viruses
b) Bacteria
c) Transposons
d) Insertion sequences
Answer: c
Clarification: Transposons are mobile genetic elements and are also known as jumping genes. These are the sequences of DNA that can move from one position to another within the genome. They were first discovered by Barbara McClintock in maize plants.
5. ______ vectors are used for the introduction of nematode specific genes in the host.
a) Bacterial
b) Viral
c) Agrobacterium
d) Meloidogyne incognitia
Answer: c
Clarification: Agrobacterium vectors are used for the introduction of nematode specific genes in the host. This was uses for RNAi technique. Initially, the host plant used was a tobacco plant.
6. A method involving silencing of specific mRNA due to the binding of complementary dsRNA is called ________
a) Electrophoresis
b) RNAi
c) rDNA technology
d) DNAi
Answer: b
Clarification: RNAi is a method involving the silencing of specific mRNA due to the binding of complementary dsRNA. It consists of various processes. It acts as a defense mechanism against viruses and transposable elements.
7. _______ prevents the translation of the mRNA.
a) Enhancing
b) Knock out
c) Clearing
d) Silencing
Answer: d
Clarification: Silencing prevents the translation of the mRNA. It regulates the expression of a gene by preventing its expression. This is used in the RNAi technique. It is a method used for knowing the function of the gene.
8. In RNAi, the DNA is introduced into a host plant in such a way that it produces both ________
a) complementary DNA and mRNA
b) mRNA and sense RNA
c) sense and antisense RNA
d) DNA and RNA
Answer: c
Clarification: RNAi stands for RNA interference. RNAi is a method involving the silencing of specific mRNA due to the binding of complementary dsRNA. In RNAi, the DNA is introduced into a host plant in such a way that it produces both sense and antisense RNA.
9. Sense and antisense RNA are _______ to each other.
a) similar
b) same
c) complementary
d) different
Answer: c
Clarification: The strand having sequence exact same to that of mRNA is called sense strand. The antisense strand consists of a complementary sequence that of transcribed mRNA. Antisense strand serves the template for the transcription, thus sense and antisense RNA are complementary to each other.
10. Sense and antisense RNA forms _____
a) ds RNA
b) ss RNA
c) ds DNA
d) ss DNA
Answer: a
Clarification: The sense and antisense RNA forms ds RNA. The sense strand has sequence same as that of mRNA which codes for a functional protein while the antisense strand consists of complementary nucleotides as that of the sense strand.
11. Formation of _______ initiates RNAi process.
a) ds DNA
b) ssDNA
c) ss RNA
d) ds RNA
Answer: d
Clarification: Formation of ds RNA initiates the RNAi process. RNAi is a series of processes that involve the silencing of mRNA sequence which prevents translation of that sequence. It is a widely used technique used for gene silencing.
12. RNAi takes place in all prokaryotic organisms.
a) True
b) False
Answer: b
Clarification: RNAi is a series of processes that involve the silencing of mRNA sequence which prevents translation of that sequence. It takes place in all eukaryotes like animals, plants, and fungi. It is not seen in prokaryotes.