Quiz_Viruses 1. In a bacteriophage, DNA is present in: tail head in tail fibres only head and tail Explanation:In a bacteriophage, the DNA is located in the head of the virus. The head is a protein structure that encases the viral DNA, protecting it until it can be injected into a host bacterium. 2. Who among the following discovered virus? A.P. de Candolle Leeuwenhoek Beijerinck Dimitri Ivanowski Explanation:Dimitri Ivanowski is credited with the discovery of viruses. He identified the Tobacco Mosaic Virus (TMV) as a new type of infectious agent that could pass through filters that trapped bacteria. 3. 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. 4. Number of capsomeres forming capsid of TMV is: 2100 2000 2130 2105 Explanation:The capsid of the Tobacco Mosaic Virus (TMV) is composed of 2130 capsomeres. These protein subunits form a helical structure that encases the viral RNA. 5. RNA particle causing symptoms like that of a virus disease are known as: virion viroids none of these HIV Explanation:Viroids are small, circular RNA molecules that can infect plants and cause disease. Unlike viruses, viroids do not have a protein coat and rely entirely on their RNA for infection. 6. The genetic material of poxvirus is: double stranded RNA single stranded RNA circular DNA single stranded DNA Explanation:Poxviruses have double-stranded DNA as their genetic material. This allows them to replicate within the cytoplasm of the host cell, independent of the host’s nuclear machinery. 7. Which of the following protein is associated with prion disease? PrP PrPc Interferon PrPsc Explanation:PrPsc is the abnormal, disease-causing form of the prion protein. It induces the misfolding of the normal cellular prion protein (PrPc), leading to the development of prion diseases. 8. The smallest known agent of a plant disease is: viroid virus mycoplasma bacteria Explanation:Viroids are the smallest known agents of plant disease. They are composed of a short strand of circular RNA and lack a protein coat, making them unique among pathogens. 9. 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. 10. 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. Loading …
