141. Which of the following secretes
toxins during storage conditions of crop plants?
(1) Fusarium
(2) Aspergillus
(3) Colletotrichum
(4) Penicillium
142. Which statement is correct for
bacterial transduction?
(1) Bacteria obtained its DNA directly
(2) Transfer of some genes from one bacteria to another bacteria through
virus
(3) Bacteria obtained DNA from other
external source
(4) Transfer of genes from one bacteria
to another bacteria by conjugation
143. In bacteria, plasmid is
(1) non-functional DNA
(2) extra – chromosomal material
(3) repetitive gene
(4) main DNA
144. Which bacteria is utilized in gober
gas plant?
(1) Ammonifying bacteria
(2) Methanogens
(3) Denitrifying bacteria
(4) Nitrifying bacteria
145. Some bacteria are able to grow in
Streptomycin containing medium due to
(1) reproductive isolation
(2) natural selection
(3) genetic drift
(4) Induced mutation
146. Chromosomes in a bacterial cell can
be 1 – 3 in number and
(1) are always linear
(2) can be circular as well as linear
within the same cell
(3) can be either circular or linear,
but never both with in the same cell
(4) are always circular
147. Viruses are no more “alive” than
isolated chromosomes because
(1) they both need food molecules
(2) both require the environment of a cell to replicate
(3) they both require oxygen for
respiration
(4) they require both RNA and DNA
148. The chief advantage of encystment
to an Amoeba is
(1) the ability to live for sometime
without ingesting food
(2) the chance to get rid of accumulated
waste products
(3) protection from parasites and
predators
(4) the ability to survive during adverse physical conditions
149. During the formation of bread it
becomes porous due to release of CO2 by the action of
(1) Virus
(2) Yeast
(3) Protozoans
(4) Bacteria
150. Which fungal disease spreads by
seed and flowers?
(1) Covered smut of barley
(2) Loose smut of wheat
(3) Soft rot of potato
(4) Corn stunt
151. Which of the following statements
is not true for retroviruses?
(1) The genetic material in mature
retroviruses is RNA
(2) DNA is not present at any stage in the life cycle of retroviruses
(3) Retroviruses are causative agents
for certain kinds of cancer in man
(4) Retroviruses carry gene for
RNAdependent DNA polymerase
152. Which one of the following pairs is
not correctly matched?
(1) Spirulina - Single cell protein
(2) Streptomyces - Antibiotic
(3) Rhizobium - Biofertilizer
(4) Serratia - Drug addiction
153. Lichens are well known combination
of an alga and a fungus where fungus has
(1) a parasitic relationship with the
alga
(2) a saprophytic relationship with the
alga
(3) a symbiotic relationship with the alga
(4) an epiphytic relationship with the
alga
154. Tobacco mosaic virus is a tubular
filament of size
(1) 300 × 5 nm
(2) 700 × 30 nm
(3) 300 × 20 nm
(4) 300 × 10 nm
155. Which one of the following
statements about viruses is correct?
(1) All viruses contain both RNA and DNA
(2) Nucleic acid of viruses is known as
capsid
(3) Viruses are obligate parasites
(4) Viruses possess their own metabolic
system
156. For retting of jute the fermenting
microbe used is
(1) Helicobactor pylori
(2) Methophilic bacteria
(3) Streptococcus lactin
(4) Butyric acid bacteria
157. All of the following statements
concerning the Actinomycetes filamentous soil bacterium Frankia are correct except
that Frankia:
(1) Forms specialized vesicles in which
the nitrogenase is protected from oxygen by a chemical barrier involving
triterpene hopanoids
(2) Can induce root nodules on many
plant species
(3) Like Rhizobium, it usually infects
its host plant through root hair deformation and stimulates cell proliferation
in the host’s cortex
(4) Cannot fix nitrogen in the free-living state.
158. Auxopores and hormocysts are
formed, respectively, by:
(1) Several cyanobacteria and several
diatoms
(2) Some diatoms and several
cyanobacteria
(3) Several diatoms and a few cyanobacteria.
(4) Some cyanobacteria and diatoms
159. Viruses that infect bacteria,
multiply and cause their lysis, are called
(1) lytic
(2) lysozymes
(3) lysogenic
(4) lipolytic
160. The most thoroughly studied fact of
the known bacteriaplant interactions is the
(1) nodulation of Sesbania stems by
nitrogen fixing bacteria
(2) cyanobacterial symbiosis with some
aquatic ferns
(3) plant growth stimulation by
phosphatesolubilising bacteria
(4) gall formation on certain angiosperms by Agrobacterium