This set of Biology Written Test Questions for Schools focuses on “Biotechnology Applications – Pest Resistant Plants – 2”.
1. Which agriculturally important bacterial gene is isolated from Rhizobium?
a) Nif gene
Explanation: Nif genes are a set of genes that are involved in atmospheric nitrogen fixation. They are isolated from a bacterium Rhizobium. It is a Gram-negative bacterium which symbiotically assists the leguminous plants and fix nitrogen.
2. Delay in the ripening of tomato is due to_____
a) virulent gene
b) antisense PG
c) antibiotic resistance gene
Explanation: PG stands for an enzyme called polygalacturonase which is responsible for pectin degradation leading to early ripening. Antisense PG inhibits the formation of polygalacturonase thus delaying the process of ripening.
3. The transgenic tomato variety with an improved shelf life is ______
a) Lyco 100
b) PHB tomato
c) Bt tomato
d) Flavr savr
Explanation: Flavr savr is a genetically modified tomato. It was the first GM food crop to be used commercially. It has a longer shelf life due to the incorporation of the antisense genes within its genome.
4. The transgenic plant ‘Flavr savr’ tomato carries an artificial gene for ______
a) delaying ripening process
b) added flavours
c) both delaying ripening process and added flavours
d) insect resistance
Explanation: The Flavr savr tomato carries an antisense PG gene which inhibits the activity of pectin degrading enzyme called polygalacturonase. This artificial gene delays the ripening process and increasing shelf life. It also adds flavor to the tomato.
5. Two bacteria found to be very useful in genetic engineering experiments are _______
a) Nitrosomonas and Klebsiella
b) Nitrobacter and Azotobacter
c) Escherichia and Agrobacterium
d) Rhizobium and Diplococcus
Explanation: Escherichia and Agrobacterium are the two most widely used bacteria for genetic engineering. Escherichia is useful for obtaining many products such as insulin while Agrobacterium is used for producing Bt crops.
6. Transgenic plants carry desirable traits like _______
a) harmful genes
b) herbicide resistance
c) lactose intolerance
d) complementary genes
Explanation: Transgenic plants carry desirable traits like herbicide resistance. Few herbs are weeds that interfere with the growth of normal desirable plants. Transgenic plants also carry other characteristics like disease-resistance, insect-resistance, etc.
7. Strains of Bacillus thuringiensis are being used for designing ______
c) biometallurgical techniques
d) bioinsecticidal plants
Explanation: Bacillus thuringiensis is mainly used for the production of bioinsecticidal plants. Bacillus thuringiensis along has a cry gene that kills the organism. This gene is carried with a vector of Agrobacterium tumefaciens.
8. Natural genetic engineer is ________
a) Pseudomonas putida
b) Escherichia coli
c) Agrobacterium tumefaciens
d) Bacillus subtilis
Explanation: the natural genetic engineer is Agrobacterium tumefaciens. It is so-called because its plasmid (Ti plasmid) is used as a vector for the transfer of the insect-resistance gene called cry gene obtained from Bacillus thuringiensis.
9. Flavr savr variety of tomato is the improved variety developed through ________
a) hybridization between old varieties
b) mutation variety
c) incorporation of a transgene
d) hybridization between a modern variety and a wild variety
Explanation: Flavr savr is a genetically modified tomato developed through the incorporation of a transgene. The transgene introduced was the antisense PG gene which interferes with the enzyme called polygalacturonase thus increasing the shelf life of tomato.
10. Insect pest resistance Bt-cotton plant was developed using ________
a) transgenic technology
b) somaclonal variation
d) somatic hybridization
Explanation: Transgenic technology was used to develop Bt-cotton. It allows the introduction of the new and functional genes in the cell. This produces a new and better variety of crops. For example, Bt-cotton is a transgenic crop and is insect resistance.
11. A desirable change in the genotype of an organism is obtained by _______
a) m-RNA formation
b) DNA replication
c) protein synthesis
d) rDNA technology
Explanation: rDNA technology is a series of processes in which molecules of DNA from two different species of the organism are inserted within a host to introduce new characters within that host. This often lead to the formation of new and better host species.
Sanfoundry Global Education & Learning Series – Biology – Class 12.
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