November 30, 2024 by Vijay Wardhan 1. Viruses are commonly transmitted in plants through: water wind animals sucking insects (Insect vectors) Explanation:Viruses are commonly transmitted in plants through sucking insects such as aphids and whiteflies. These insects act as vectors, transferring the virus from infected to healthy plants. 2. The site where the protein coat of virus is synthesized is: mitochondria of the host plasma membrane of the host ribosome of the host RNA of the virus Explanation:The protein coat (capsid) of a virus is synthesized by the host cell’s ribosomes. The viral RNA or DNA directs the host’s ribosomes to produce viral proteins, which then assemble into the capsid. 3. Infective nature of Tobacco mosaic disease was discovered by: Ivanowski Mayer Green Bawden Explanation:Adolf Mayer discovered the infectious nature of Tobacco Mosaic Disease. He demonstrated that the disease could be transmitted from plant to plant, laying the groundwork for the study of plant viruses. 4. Detailed study of bacteriophage was made by: Stanley Ivanowski d’Herelle Twort Explanation:Felix d’Herelle conducted detailed studies on bacteriophages, viruses that infect bacteria. His work provided significant insights into the nature and behavior of bacteriophages. 5. Yellow vein Mosaic of Bhindi Virus (Hibiscus Virus-I) is transmitted through: butterflies white flies fungal mycelium moth Explanation:The Yellow Vein Mosaic Virus of Bhindi (Okra) is transmitted by whiteflies. These insects act as vectors, spreading the virus from infected to healthy plants. 6. In which of the following, RNA is double stranded: wound tumour virus reovirus none of the above both (a) and (b) Explanation:Both reovirus and wound tumour virus have double-stranded RNA as their genetic material. This is a unique characteristic among viruses, as most RNA viruses have single-stranded RNA. 7. Infective portion of a virus is nucleic acid, this was discovered by: Hershey and Chase d’Herelle Ivanowski Stanley Explanation:Hershey and Chase’s experiments with bacteriophages demonstrated that the nucleic acid (DNA) is the infective part of the virus. Their work confirmed that DNA carries genetic information. 8. Which of the following disease is caused by virus? Typhoid T.B. Polio Diphtheria Explanation:Polio is caused by the poliovirus, which infects the nervous system and can lead to paralysis. The disease has been largely eradicated through widespread vaccination efforts. 9. Viroids have: single stranded DNA not enclosed by protein coat single stranded RNA not enclosed by protein coat (naked RNA) double stranded RNA enclosed by protein coat double stranded DNA enclosed by protein coat Explanation:Viroids are composed of single-stranded RNA that is not enclosed by a protein coat. This naked RNA is capable of infecting plants and causing disease. 10. What is a vector? Natural reservoir of disease An organism which carries and transmits disease causing microorganism Pathogenic protozoa Human parasite Explanation:A vector is an organism that carries and transmits pathogens to other living organisms. Examples include mosquitoes transmitting malaria and ticks transmitting Lyme disease. Loading …
