Tips and Tricks of The Day

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Ex: Soil erosion can be prevented by:
A) Overgrazing
B) Removal of vegetation
C) Afforestation
D) Increasing birds population
Explanation: Afforestation means to cultivate the forest. The soil is hold by the roots of the forest plants and soil erosion can be prevented.
Ex: Rhizobium lives symbiotically with root nodules and fixes atmospheric nitrogen. It gives nitrogenous compound to host and inturn takes food from host. This food taken by bacterium is:
A) Fats
B) Proteins
C) Carbohydrates
D) None of these
Explanation: Plants manufacture their food in the form of carbohydrate by the process of photosynthesis. Hence the food taken by bacterium is carbohydrate.
Ex: A feature common to gametophytes and sporophytes of mosses and ferns:
A) Independent existence
B) Autotrophic nutrition
C) Unbranched habit
D) Branched habit
Explanation: Autotrophic nutrition is a common feature to gametophytes and sporophytes of mosses and fern because chlorophyll containing cells found in both which are assimilatory in function.
Ex: For the manufacture of gluconic acid and citric acid, which of the following  micro-organism is used:
A) Aspergillus niger
B) Gluconobacter sp.
C) Lactobacillus bulgaricus
D) Acetobacter sp.
Explanation: Gluconic acid is produced, during glucose oxidation by most Aspergillus sps. and citric acid is obtained by the fermentation of sugar syrup by Aspergillus  niger.
Ex: The plant cell wall is made up of cellulose. This is believed to be:
A) A polysaccharide
B) An amino acid
C) A liquid
D) A protein
Explanation: A polysaccharide is made up of many units of monosaccharides.
Ex: In Langmuir's model of adsorption of a gas on a solid surface:
A. The rate of dissociation of adsorbed moleclues from the surface does not depend on the surface covered
B. The adsorption at a single site on the surface may involve multiple molecules at the same time
C. The mass of gas striking a given area of surface is independent of the pressure of the gas
D. The mass of gas striking a given area of surface is proportional to the pressure of the gas
Ex: Gas used for sterilizing water is:
A) SO2
B) CO2
C) O3
D) NH3
Explanation: Ozone  is an excellent disinfectant with the superior ability to kill viruses and biological contaminants found in water. It is also a very powerful oxidant that can oxidize metals in water such as manganese, iron, and sulfur into insoluble particles, aiding in their filtration and removal from water.
Ex: Organisms called Methanogens are most abundant in a:
a) Sulphur rock
b) Hot spring
c) Polluted stream
d) Cattle yard
Explanation: Methanogens are archaebacteria abundant in cattle yard and paddy fields.
Ex: The function of leghaemoglobin in the root nodules of legumes is Inhibition of.
A. Nitrogenase activity 
B. Oxygen removal
C. Nodule differentiation
D. Expression of nif gene
Explanation: The root nodiles of legume contains enzyme nitrogenase and leghaemoglobin. Nitrogenase is highly sensitive to the molecular oxygen and requires that ensure that the enzyme is pretected from oxygen to protect these enzyme the nodule contains an oxygen scavenger called leghaemeglobin
Ex: Which of the fol does not have any enzymes in its cells?
A. Lichen 
B. virus 
C. Bacteria 
D. None of the above
Explanation: Virus possess genes that could code for several enzymes.
Genes that code for enzymes , Enzyme production only begins when the virus infects a host cell and takes over the cell machinery and resources to transcribe its own genome.
Bacteria are living cells which have the capabilities of consuming wastes of different types, reproducing, and actually producing enzymes.