(i) The additional circular pieces of DNA present in a bacterial cell are: (a) RNA (b) nucleotides (c) chromatids (d) plasmids (ii) What may be the objective of genetic modifications of plants? (a) Production of disease resistant plants (b) Improvement in nutritional quality of plants (c) Production of herbicide resistant plants (d) All of these (iii) Plasmid and attached foreign gene with it are collectively called: (a) recombinant cell (b) recombinant DNA (c) recombinant plasmid (d) recombinant chromosome (iv) The organisms whose cells and plasmids are usually used in genetic engineering are: (a) bacteria (b) fungi (c) algae (d) viruses (v) Sections of DNA serving as codes for developing characters in an organism are called: (a) genes (b) nucleotides (c) plasmids (d) proteins (vi) Which of the following is not a biotechnology product? (a) Insulin (b) Quinine (c) Beta-endorphin (d) Interferon (vii) How do genetic engineers get insulin for diabetic patients? (a) Isolate from human pancreas (b) Isolate from pancreas of other animals (c) Insulin gene inserted in human pancreas (d) Insulin gene inserted in bacteria
Answer (1)
(i) The additional circular pieces of DNA present in a bacterial cell are: (d) plasmids.
Explanation : Plasmids are small, circular, double-stranded DNA molecules that are separate from a cell's chromosomal DNA. They naturally exist in bacterial cells and some eukaryotes. Plasmids are often used in genetic engineering because they can replicate independently from the chromosomal DNA.
(ii) What may be the objective of genetic modifications of plants? The correct choice is: (d) All of these.
Explanation : Genetic modifications of plants can have various objectives such as:
Production of disease-resistant plants : Introducing genes that help plants resist diseases.
Improvement in nutritional quality of plants : Modifying plants to increase their nutritional content.
Production of herbicide-resistant plants : Making plants resistant to specific herbicides, allowing for better weed control.
(iii) Plasmid and attached foreign gene with it are collectively called: (b) recombinant DNA.
Explanation : Recombinant DNA is formed by inserting a gene of interest into a plasmid. This process creates a new set of genes, known as recombinant DNA, which can be introduced into an organism.
(iv) The organisms whose cells and plasmids are usually used in genetic engineering are: (a) bacteria.
Explanation : Bacteria are frequently used in genetic engineering as hosts to propagate recombinant DNA. Their plasmids are also used as vectors to introduce foreign DNA into other organisms.
(v) Sections of DNA serving as codes for developing characters in an organism are called: (a) genes.
Explanation : Genes are units of heredity and are made up of DNA. They determine specific traits by coding for proteins or regulating the expression of other genes.
(vi) Which of the following is not a biotechnology product? (b) Quinine.
Explanation : Quinine is a natural product originally derived from the bark of the cinchona tree and is not created using biotechnology techniques. Insulin, beta-endorphin, and interferon can be produced through biotechnological processes.
(vii) How do genetic engineers get insulin for diabetic patients? (d) Insulin gene inserted in bacteria.
Explanation : Genetic engineers insert the human insulin gene into bacteria, typically E. coli . These bacteria then produce insulin, which is harvested, purified, and used for diabetes treatment. This method is more efficient and ethical compared to extracting insulin from animal sources.
