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

Cells in some filamentous cyanobacteria that are specialized for nitrogen fixation are called:

1. Phycobilisomes

2. Chromatophores

3. Grana

4. Heterocysts

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

Which of the following are found in extreme saline conditions?

1. Archaebacteria

2. Eubacteria

3. Cyanobacteria

4. Mycobacteria

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 one of the following is wrong for fungi?

(1) They are eukaryotic

(2) All fungi possess a purely cellulosic cell wall

(3) They are heterotrophic

(4) They are both unicellular and multicellular

Methanogens belong to

1. eubacteria

2. archaebacteria

3. dinoflagellates

4. slime moulds

Select the wrong statement.

(1) The walls of diatoms are easily destructible

(2) 'Diatomaceous earth' is formed by the cell walls of diatoms

(3) Diatoms are chief producers in the oceans

(4) Diatoms are microscopic and float passively in water

Chrysophytes, euglenoids, dinoflagellates and slime moulds are included in the kingdom

1. Protista

2. Fungi

3. Animalia

4. Monera

The primitive prokaryotes responsible for the production of biogas from the dung of ruminant animals, include the

(1) thermoacidophiles

(2) methanogens

(3) eubacteria

(4) halophiles