Which of the following is correct about viroids?

1. They have free RNA without protein coat.

2. They have DNA with protein coat.

3. They have free DNA without protein coat.

4. They have RNA with protein coat.

Which of the following statements is incorrect?

1. Prions consist of abnormally folded proteins

2. Viroids lack a protein coat

3. Viruses are obligate parasites

4. Infective constituent in viruses is the protein coat

Mad cow disease in cattle is caused by an organism which has:

1. Inert crystalline

2. Abnormally folded protein

3. Free RNA without protein coat

4. Free DNA without protein coat

Which of the following statements is correct?

1. Lichens do not grow in polluted areas.

2. Algal component of lichens is called mycobiont.

3. Fungal component of lichens is called phycobiont.

4. Lichens are not good pollution indicators.

Viroids differ from viruses in having;

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

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