True nucleus is absent in

(1) Anabaena

(2) Mucor

(3) Vaucheria

(4) Volvox

Cell wall is absent in

(1) Aspergillus

(2) Funaria

(3) Mycoplasma

(4) Nostoc

Which of the following shows coiled RNA strand and capsomeres?

(1) Polio virus

(2) Tobacco mosaic virus

(3) Measles virus

(4) Retrovirus

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

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. Beijerinck.

(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