Identify the incorrect statement:
| 1. | Virus has a protein coat called capsid made of small subunits called capsomeres. |
| 2. | The core has the genetic material - either RNA or DNA or both. |
| 3. | The capsomeres are arranged in helical or icosahedral forms. |
| 4. | Viruses can infect any type of organism. |
Match the Scientists in Column I with their contribution in the field of virology given in Column II and select your answer from the codes given below:
| Column I | Column II | ||
| A. | Ivanowsky | a. | Recognized tobacco mosaic is caused by microbes smaller than bacteria |
| B. | Beijerinck | b. | Demonstrated extract of infected tobacco plants could cause infection in healthy plants |
| C. | Stanley | c. | Showed that viruses could be crystallized |
Codes:
| A | B | C | |
| 1. | a | b | c |
| 2. | a | c | b |
| 3. | b | a | c |
| 4. | b | a | d |
What is true for both (a) and (b)?
1. RNA is the genetic material
2. Capability to infect bacteria
3. Being obligate endoparasites
4. Can be killed by antibiotics
Viroids differ from viruses in having
1. DNA molecules with protein coat
2. DNA molecules without protein coat
3. RNA molecules with protein coat
4. RNA molecules without protein coat
Which of the following statements is wrong for viroids?
1. They are smaller than viruses
2. They cause infections
3. Their RNA is of high molecular weight
4. They lack a protein coat
Which statement is wrong for viruses?
1. All are parasites
2. All of them have helical symmetry
3. They have ability to synthesize nucleic acids and proteins with the help of host cell
4. Antibiotics have no effect on them
T. O. Diener discovered a
1. free infectious RNA
2. free infectious DNA
3. infectious protein
4. bacteriophage
Which of the following shows coiled RNA strand and capsomeres?
1. Polio virus
2. Tobacco mosaic virus
3. Measles virus
4. Retrovirus
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