Select the wrong statement:

Which of the following shows coiled RNA strand and capsomeres?

Viruses have:
1. DNA enclosed in a protein coat
2. Prokaryotic nucleus
3. Single chromosome
4. Both DNA and RNA

Which statement is wrong for viruses?
1. All are parasites
2. All of them have helical symmetry
3. They have the ability to synthesize nucleic acids and proteins 
4. Antibiotics have no effect on them

Virus envelope is known as:
1. capsid
2. virion
3. nucleoprotein
4. core

Infectious proteins are present in:
1. geminiviruses
2. prions
3. viroids
4. satellite viruses

Given below is the diagram of a bacteriophage. In which one of the options, all the four parts A, B, C and D are correct?

T.O. Diener discovered a:
1. free infectious RNA
2. free infectious DNA
3. infectious protein
4. bacteriophage

The causative agent of mad-cow disease is a:

1. bacterium

2. prion

3. worm

4. virus