Biological Classification

Bacterial leaf blight of rice is caused by a species of

1. Alternaria
2. Erwinia
3. Xanthomonas
4. Pseudomonas

Thermococcus, Methanococcus and Methanobacterium exemplify

1. bacteria whose DNA is relaxed or positively supercoiled but which have a cytoskeleton as well as mitochondria
2. bacteria that contain a cytoskeleton and ribosomes
3. archaebacteria that contain protein homologous to eukaryotic core histones
4. archaebacteria that lack any histones resembling those found in eukaryotes but whose DNA is negatively supercoiled

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

1. Archaea completely differ from both prokaryotes and eukaryotes.
2. Archaea completely differ from prokaryotes.
3. Archaea resemble eukarya in all respects.
4. Archaea have some novel features that are absent in other prokaryotes and eukaryotes.

Cellulose is the major component of cell walls of

1. Pseudomonas
2. Saccharomyces
3. Pythium
4. Xanthomonas

Which one of the following is a slime mould?

1. Physarum
2. Thiobacillus
3. Anabaena
4. Rhizopus

Which one of the following statements about Mycoplasma is wrong?

1. They are pleomorphic.
2. They are sensitive to penicillin.
3. They cause diseases in plants.
4. They are also called PPLO.

Which pair of the following belongs to basidiomycetes?

1. Puffballs and Claviceps
2. Peziza and stinkhorns
3. Morchella and mushrooms
4. Bird's nest fungi and puffballs

Which of the following environmental conditions are essential for optimum growth of Mucor on a piece of bread? Choose the answer from the following options.

1. B, C and F only
2. A, C and E only
3. A, D and E only
4. B, D and E only

What is common about Trypanosoma, Noctiluca, Monocystis and Giardia?

1. These are all parasites
2. These are all unicellular protists
3. They have flagella
4. They produce spores

The causative agent of mad-cow disease is a-

1. Virus
2. Bacterium
3. Prion
4. Worm