In 1971, T.O. Diener discovered a new infectious agent that was smaller than viruses –

The above statements are assigned to –
1. Viruses
2. Viroids
3. Virulent
4. Mycoplasma

Which of the following statement is incorrect?
a. Viroids are smaller than viruses.
b. Viroid was found to be a free RNA.
c. The RNA of the viroid is of high molecular weight.
d. In 1971, T.O. Diener discovered it.

Lichens, viruses, viroids and prions have been included in the kingdom –
a. Monera
b. Protista
c. Plantae
d. None of the above

Which of the following disease is not caused by Prions?
a. Bovine spongiform encephalopathy (BSE) in cattles
b. Cr–Jacob disease (CJD) in humans.
c. Mad cow disease in cattle
d. Potato Spindle Tuber disease

Viroids have

(1) single stranded RNA not enclosed by protein coat

(2) single stranded DNA not enclosed by protein coat

(3) double straded DNA enclosed by protein coat

(4) double stranded RNA enclosed by protein coat

Which of the following pathogenic disease could have the symptoms like mosaic formation, leaf rolling and curling, yellowing and vein clearing, dwarfing and stunted growth?

a. Viral
b. Bacterial
c. Fungal
d. Deficiency syndrome.

Match the columns.

Select correct option

1. a-p, b-q, c-r, d-s

2. a-s, b-r, c-q, d-p

3. a-q, b-s, c-r, d-p

4. a-q, b-s, c-p, d-r

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 of the following shows coiled RNA strand and capsomeres?

(1) Polio virus

(2) Tobacco mosaic virus

(3) Measles virus

(4) Retrovirus

Which of the following is not correctly matched?