The Ti plasmid used in plant genetic engineering is derived from:
A. Agrobacterium tumefaciens
B. Pseudomonas putida
C. Bacillus subtilis
D. Escherichia coli
Answer: Option A
Solution (By JKExamLibrary)
Agrobacterium tumefaciens is a soil bacterium that naturally transfers part of its Ti (tumor-inducing) plasmid DNA (T-DNA) into the plant genome, causing crown gall disease. Scientists have harnessed this capability by replacing the tumor-causing genes with desirable genes, making it a vector for creating transgenic plants. E. coli vectors are used for bacterial transformation.
Explanation:
Hemoglobin in red blood cells binds oxygen in the lungs and releases it in tissues. Each hemoglobin molecule can bind four O₂ molecules. It also carries some CO₂.
Explanation:
In 1885, Louis Pasteur developed the first effective vaccine against rabies. He achieved this by serially passaging the rabies virus (obtained from the saliva of infected dogs) through the spinal cords of rabbits. This process attenuated (weakened) the virus for rabbits but made it virulent for dogs. He then dried the infected spinal cords to further weaken the virus and used this attenuated material to successfully inoculate and protect a boy, Joseph Meister, who had been bitten by a rabid dog.
Explanation:
The neuron is the basic structural and functional unit of the nervous system, consisting of a cell body, dendrites, and an axon. It transmits electrical impulses.
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