3636 MTMTBIOLOGY TODAYBIOLOGY TODAY || march ‘16march ‘16
- Which of the following statements regarding antibiotics
is not correct?
(i) antibiotics are the attenuated microorganisms which
in small concentration, can kill or retard the growth
of other harmful microorganisms.
(ii) Penicillin was the first antibiotic discovered by
alexander Fleming (1928) while working on bacterium
Staphylococcus aureus.
(iii) The full potential of penicillin as an effective antibiotic
was established by Ernst chain and howard Florey.
(iv) Fleming, chain and Florey were awarded the Nobel
Prize in 1945.
(a) (i) only (b) (iii) only
(c) (ii) and (iv) (d) (i), (iii) and (iv) - Wine and beer are produced directly by fermentation
whereas brandy and whisky require both fermentation and
distillation. This is because
(a) fermentation is inhibited at an alcohol level of 10-18%
(b) distillation prolongs storage
(c) distillation improves quality
(d) distillation purifies the beverage. - During the primary treatment of sewage, solid particles that
settle down are called
(a) flocs (b) primary sludge
(c) activated sludge (d) anaerobic sludge. - When domestic sewage mixes with river water
(a) small animals like rats will die after drinking river water
(b) the increased microbial activity releases micronutrients
such as iron
(c) the increased microbial activity uses up dissolved oxygen
(d) the river water is still suitable for drinking as
impurities are only about 0.1%. - cyanobacteria helps farmers by
(a) reducing the alkalinity of the soil
(b) reducing the acidity of the soil
(c) neutralising the alkalinity of the soil
(d) water logging. - Select the correct statement regarding activated sludge
formed during secondary sewage treatment.
(a) a small part of it is rapidly pumped back from
sedimentation tank to aeration tank.
(b) It absorbs pathogenic bacteria present in waste water
while sinking to the bottom of the settling tank.
(c) a major part of it is anaerobically digested.
(d) Both (a) and (c) - mycorrhizal dessiciations do not help the host plant in
(a) enhancing its phosphorus uptake capacity
(b) increasing its tolerance to salinity and drought
(c) enhancing its resistance to root borne pathogens
(d) increasing its resistance to insects.
9. activated sludge should have the ability to settle quickly
so that it can
(a) be rapidly pumped back from sedimentation tank to
aeration tank
(b) absorb pathogenic bacteria present in waste water
while sinking to the bottom of the settling tank
(c) be discarded and anaerobically digested
(d) absorb colloidal organic matter.
10. Which of the following is a wrong matching of a microbe
and its industrial product, while the remaining three are
correct?
(a) Yeast – statins
(b) Acetobacter aceti – acetic acid
(c) Clostridium butyricum – lactic acid
(d) Aspergillus niger – citric acid
True or false - Vinegar is obtained from molasses with the help of
Rhizopus. - Lactic acid bacteria convert milk into curd and improve the
nutritional quality by enhancing vitamin B content. - Invertase converts glucose into alcohol.
- The dough which is used for making foods such as dosa
and idli is fermented by certain species of bacteria. - Biogas generation is a five stage aerobic digestion of animal
and other organic wastes. - People recovering from long illness are often advised to
include Spirulina their diet as it is rich in protein. - Nitrogen fixation in root nodules of Alnus is carried out by
Frankia. - Bacillus thuringiensis bacteria are available as dried spores
which are mixed with water and sprayed onto vulnerable plants. - Azotobacter available under the trade name of azotobactrin,
not only increases yield, but also saves nitrogen fertilisers
in fields of cotton, maize, jowar and rice. - Lipases are lipid dissolving enzymes obtained from
Saccharomyces fragilis and Torula cremoris.
match The columns - match column-I with column-II.
Column-I Column-II
a. Lactobacillus (i) Formation of Swiss
acidophilus cheese
B. Saccharomyces (ii) Bacitracin
cerevisiae
c. Propionibacterium (iii) Single cell proteins
sharmanii
D. Spirulina (iv) Formation of milk into
curd
E. Bacillus licheniformis (v) Formation of dough