Biological Classification

Select the correct combination of the statements (i – iv) regarding the characteristics of certain organisms. (i) Methanogens are archaebacteria which produce methane in marshy areas. (ii) Nostoc is a filamentous blue-green alga which fixes atmospheric nitrogen. (iii) Chemosynthetic autotrophic bacteria synthesise cellulose from glucose. (iv) Mycoplasma lack a cell wall and can survive without oxygen. The correct statements are

1. (ii) and (iii)
2. (i), (ii) and (iii)
3. (ii), (iii) and (iv)
4. (i), (ii) and (iv)

Black (stem) rust of wheat is caused by

1. Alternaria solani
2. Ustilago nuda
3. Puccinia graminis
4. Xanthomonas oryzae

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? [Figure]

1. A Collar, B Tail fibres, C Head, D Sheath
2. A Tail fibres, B Head, C Sheath, D Collar
3. A Head, B Sheath, C Collar, D Tail fibres
4. A Sheath, B Collar, C Head, D Tail fibres

Virus envelope is known as

1. capsid
2. virion
3. nucleoprotein
4. core

Single-celled eukaryotes are included in

1. protista
2. fungi
3. archaea
4. monera

Some hyperthermophilic organisms that grow in highly acidic (pH 2) habitats belong to the two groups

1. eubacteria and archaea
2. cyanobacteria and diatoms
3. protists and mosses
4. liverworts and yeasts

Infectious proteins are present in –

1. Viroids
2. Geminiviruses
3. Satellite viruses
4. Prions

T.O. Diener discovered a

1. free infectious DNA
2. infectious protein
3. bacteriophage
4. free infectious RNA

Oxygenic photosynthesis occurs in

1. Oscillatoria
2. Rhodospirillum
3. Chlorobium
4. Chromatium

Which one is the wrong pairing for the disease and its causal organism?

1. Black rust of wheat – Puccinia graminis
2. Loose smut of wheat – Ustilago nuda
3. Root knot of vegetables – Meloidogyne sp.
4. Late blight of potato – Alternaria solani