Viruses have

(1) DNA enclosed in a protein coat

(2) prokaryotic nucleus

(3) single chromosome

(4) Both DNA and RNA

Cellulose is the major component of cell walls of

(1) Pythium

(2) Xanthomonas

(3) Pseudomonas

(4) Saccharomyces

Which of the following components provides sticky character to the bacterial cell?

(1) Cell wall

(2) Nuclear membrane

(3) Plasma membrane

(4) Glycocalyx

The imperfect fungi which are decomposers of litter and help in mineral cycling belong to

(1) Deuteromycetes

(2) Basidiomycetes

(3) Phycomycetes

(4) Ascomycetes

Select wrong statement.

(1) The viroids were discovered by D.J. lvanowsky.

(2) W.M. Stanley showed that viruses could be crystallized.

(3) The term 'contagium vivum fluidum' was coined by M.W. Beijerinek.

(4) Mosaic disease in tobacco and AIDS in human being are caused by viruses.

Choose the wrong statement.

1. Penicillium is multicellular and produces antibiotics.

2. Neurospora is used in the study of biochemical genetics.

3. Morels and truffles are poisonous mushrooms.

4. Yeast is unicellular and useful in fermentation.

The structures that help some bacteria to attach to rocks and/or host tissues are

1. rhizoids

2. fimbriae

3. mesosomes

4. holdfast

In which group of organisms the cell walls form two thin overlapping shells which fit

together?

1. Chrysophytes

2. Euglenoids

3. Dinoflagellates

4. Slime moulds

Pick up the wrong statement.

1. Cell wall is absent in Animalia.

2. Protista have photosynthetic and heterotrophic modes of nutrition.

3. Some fungi are edible.

4. Nuclear membrane is present in Monera.

Which of the following are likely to be present in deep sea water ?

(1) Archaebacteria

(2) Eubacteria

(3) Blue-green algae

(4) Saprophytic fungi