Answers and bookmarks are saved in this browser, across visits. They do not sync to your account.
494 questions in this collection · Page 2 of 50
Question 11 of 494
📘 CLASS XII
Biotechnology And Its Applications
Which of the following genetically modified crops is resistant to insect pests due to the presence of a gene from Bacillus thuringiensis?
Bt cotton contains the cry gene from the bacterium Bacillus thuringiensis. This gene produces a protein toxic to certain insect pests (especially bollworms), providing resistance without harming the plant or humans.
Question 12 of 494
📘 CLASS XII
Biotechnology And Its Applications
The method of producing thousands of genetically identical plants through tissue culture in a very short duration is called:
Micro-propagation is the method of producing thousands of plants through tissue culture in short durations. Each resulting plant is genetically identical to the original plant, hence they are called somaclones.
Question 13 of 494
📘 CLASS XII
Biotechnology And Its Applications
Which of the following components must be provided in the nutrient medium for an explant grown in vitro using tissue culture techniques?
The nutrient medium must provide a carbon source such as sucrose, along with inorganic salts, vitamins, amino acids, and growth regulators like auxins and cytokinins.
Question 14 of 494
📘 CLASS XII
Biotechnology And Its Applications
Which part of a diseased plant is typically removed and grown in vitro to obtain virus-free plants?
Even if a plant is infected with a virus, the meristem (apical and axillary) is typically free of the virus. Hence, the meristem can be removed and cultured in vitro to obtain virus-free plants, a technique successfully used for banana, sugarcane, and potato.
Question 15 of 494
📘 CLASS XII
Biotechnology And Its Applications
The process where isolated naked protoplasts from two different varieties of plants are fused to generate a hybrid plant is called:
Somatic hybridisation is the process involving the fusion of naked protoplasts (cells with digested cell walls) isolated from two different plant varieties, leading to hybrid protoplasts that can grow to form somatic hybrids, such as the pomato.
Question 16 of 494
📘 CLASS XII
Biotechnology And Its Applications
What term is used for plants, bacteria, fungi, and animals whose genes have been altered by manipulation?
Plants, bacteria, fungi, and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO).
Question 17 of 494
📘 CLASS XII
Biotechnology And Its Applications
One major application of genetic modification in crops is the development of tolerance to abiotic stresses. Which of the following is considered an abiotic stress that GM crops can tolerate?
Genetic modification has made crops more tolerant to abiotic stresses such as cold, drought, salt, and heat.
Question 18 of 494
📘 CLASS XII
Biotechnology And Its Applications
Genetically Modified (GM) plants have improved efficiency of mineral usage. What is the consequence of this improvement?
GM plants have increased efficiency of mineral usage, which prevents the early exhaustion of the fertility of the soil.
Question 19 of 494
📘 CLASS XII
Biotechnology And Its Applications
The Bt toxin protein used to create insect-resistant plants is produced by which bacterium?
Bt toxin is produced by the bacterium called Bacillus thuringiensis (Bt). The gene for this toxin has been cloned and expressed in plants to provide resistance to insects.
Question 20 of 494
📘 CLASS XII
Biotechnology And Its Applications
Bt toxin proteins are known to kill certain groups of insects. Which group of insects includes flies and mosquitoes, targeted by some Bt strains?
Bt strains produce proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles), and dipterans (flies, mosquitoes).