Tips and Tricks of The Day

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Ex: Name the plant hormone that inhibits growth and also helps in wilting of leaves.
Explanation: The plant hormone that inhibits growth and also helps in wilting of leaves is known as abscisic acid.
Ex: Yeast is used in the production of:
Solution :
Yeast is used in the industrial production of ethanol (alcohol). When yeast is added to sugar solution, it causes fermentation and forms alcohol.
Ex: Enlist the main factors on which the viability of pollen grains depends.
Explanation: The viability of pollen grains varies from species to species. It depends on temperature and humidity.
Ex: Which of the following stage is affected by colchicum:
A) Metaphase
B) Prophase
C) Interphase
D) Anaphase
Explanation: Colchicine is obtained from colchicum autumnale plant, which inhibits the formation of spindle fibers in metaphase.
Ex: Suppose you have to determine the percentage of carbon dioxide in a sample of a gas available in a container. Which is the best absorbing material for the carbon dioxide .
A) Heated copper oxide
B) Cold, solid calcium chloride
C) Cold, solid calcium hydroxide
D) Heated charcoal
Explanation: CO2 is acidic oxide and thus more effectively absorbed by an alkali.
Ex: Lactic acid is produced by
A) Lactobacillus bulgaricus
B) Streptococcus lactis
C) Rhizopus oryzae
D) All the above
Explanation: Lactic acid is produced from microbial fermentation of lactose (milk sugar). Fermenting agents are bacteria, e.g., streptococcus lactis and Lactobacillus and fungi, e.g., Rhizopus.
Ex: The process by which a lake ecosystem is altered by eutrophication involves several stages, each causing the next. Which of the following stages would occur second in the chain of causation?
A) Algal blooms occur.
B) Oxygen levels drop in deeper water.
C) Phosphorus input from sewage and agricultural runoff increases.
D) Respiratory demand from decomposers increases.
Explanation: The correct sequence is : (1) Phosphorus input from sewage and agricultural runoff increases. (2) Algal blooms occur. (3) Respiratory demand from decomposers increases. (4) Oxygen levels drop in deeper water.
Ex: Biotechnology deals with industrial scale production of biopharmaceuticals and biological products using genetically modified:
A) microbes only
B) plants and animals only
C) fungi only
D) All of the above
Explanation: Biotechnology is the exploitation of biological processes for industrial and other purposes, especially the genetic manipulation of microorganisms (like microbes, fungi, plants and animals) for the production of antibiotics, hormones, etc.
Ex: The reaction 2NO(g) + O2(g) ⇌ 2NO2(g) is of first order. If volume of reaction vessel is reduced to 1/3, the rate of reaction would be:
A) 1/3 times            
B) 2/3 times
C) 3 times 
D) 6 times
Explanation: For following reaction,2NO(g)+O2(g)→2NO2(g) When the volume of vessel change into 1/3 then concentration of reactant become three times. The rate of reaction for first order reaction ∝ concentration. So rate of reaction will increases three times.
Ex: Most cells divide if they receive the proper signal at a checkpoint in the ____ phase of the cell cycle.                
A) M                                
B) G1
C) S                                 
D) G2
Explanation: If at G1 cells are given the signal to divide, they are unlikely to be stopped at subsequent checkpoints.