Biological Oxygen Demand (BOD) is a measure of

• Industrial wastes poured into water bodies

• The extent to which water is polluted with an organic compound

• Amount of carbon monoxide inseparably combined with haemoglobin

• Amount of oxygen needed by green plants during the night 

Assertion : Curdling is required in the manufacture of cheese.

Reason : Lactic acid bacteria are used for the purpose.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false

Select the correct pair of microorganism and the product obtained from it.

• Monascus purpureus- produces large holes in Swiss cheese.

• Saccharomyces cerevisiae - used for making wine and beer after distillation

• Streptococcus - produces streptokinase which is used to remove clots.

• Aspergillus niger - produces citric acid and butyric acid.

Assertion: While working on Staphylococci, Alexander Fleming observed that Penicillin nolatum inhibits the growth of the bacteria.

Reason : This inhibiting chemical was commercially extracted and its full potential was established by Alexander Fleming.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are hue but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

45.

The growth curve of bacterial population in lab is plotted against time. What will be the shape of graph

• Sigmoid

• Hyperbolic

• Ascending straight line

• Descending straight line

Pollution from animal excreta and organic waste from kitchen can be most profitably minimized by

• storing them in underground storage tanks

• using them for producing biogas

• vermiculture

• using them directly as biofertilizers

Continued consumption of a diet rich in butter, red meat and eggs for a long period may lead to:

• vitamin toxicity

• kidney stones

• hypercholesterolemia

• urine laden with ketone bodies

Latest trend in plant disease control is

• chemical control

• biological control

• good manure and fertilizer

• breeding for disease resistance

Assertion : Yeasts such as Saccharomyces cerevisiae are used in baking industry.

Reason : Carbon dioxide produced during fermentation causes bread dough to rise by thermal expansion.

• If both Assertion and Reason are true and the reason is the correct explanation of the assertion

• If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

• If Assertion is true statement but Reason is false

• If both Assertion and Reason are false statements

One of the major difficulties in the biological control of insect pests is the :

• practical difficulty of introducing the predator to specific areas

• method is less effective as compared with the use of insecticides

• predator does not always survive when transferred to a new environment

• predator develops a preference to other diets and may itself become a pest