Single-celled eukaryotes are included in 

Some hyperthermophilic organisms that grow in highly acidic (pH2) habitats belong to the two groups called

(1) eubacteria and archaea

(2) cyanobacteria and diatoms

(3) protists and mosses

(4) liverworts and yeasts

Virus envelope is known as

(1) capsid

(2) virion

(3) nucleoprotein

(4) core

T. O. Diener discovered a

(1) free infectious RNA

(2) free infectious DNA

(3) infectious protein

(4) bacteriophage

Infectious proteins are present in

(1) gemini viruses

(2) prions

(3) viroids

(4) satellite viruses

In the light of recent classification of living organisms into three domains of life (bacteria, archaea and eukarya), which one of the following statement is true about archaea?

(1) Archaea resemble eukarya in all respects

(2) Archaea have some novel features that are absent in other prokaryotes and eukaryotes

(3) Archaea completely differ from both prokaryotes and eukaryotes

(4) Archaea completely differ from prokaryotes

Membrane-bound organelles are absent in

(1) Saccharomyces

(2) Streptococcus

(3) Chlamydomonas

(4) Plasmodium

Oxygenic photosynthesis occurs in

(1) Chromatium

(2) Oscillatoria

(3) Rhodospirillum

(4) Chlorobium

Bacterial leaf blight of rice is caused by a species of

(1) Xanthomonas

(2) Pseudomonas

(3) Alternaria

(4) Erwinia