Tips and Tricks of The Day

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    2019-03-19 11:23:13.0
Ex: A plant hormone used for inducing morphogenesis in plant tissue culture is
A) Abscisic acid
B) Gibberellins
C) Cytokinins
D) Ethylene
Explanation: Cytokinin is a plant hormone which plays a part in organ formation (morphogenesis) with auxin.
    2019-03-18 11:02:03.0
Ex: If we remove half of the forest cover of earth, the crisis that will occur
A) Many species would become extinct
B) Population, pollution and ecological imbalance will rise
C) Energy crisis will commence
D) The remaining forest will correct the imbalance
Explanation: Habitats of a large variety of organisms would be destroyed and food chains would be disturb leading to population and ecological imbalance.
    2019-03-15 12:30:27.0
Ex: Which of the following pesticides is an acetylcholinesterase inhibitor
A) Aldrin
C) Endosulfan
D) Malathion
Explanation: Malathion is an organophosphate pesticide which has strong effect on nervous system. It inhibits the action of acetylcholinesterase
    2019-03-14 11:53:11.0
Ex: Reserpine an alkaloid or drug extracted from roots of the following plant which cures the mental disorders and reduces or check the blood pressure or A hypertension drug is derived from 
A) Rauwolfia serpentina
B) Ferula asafoetida
C) Atropa belladona
D) Digitalis perpurea
Explanation: Rauwolfia serpentina or Reserpine (Family - Apocyanaceae) has several alkoloids - reserpine, reserpinine, serpentine, sarpajmaline etc.
    2019-03-13 11:56:58.0
Ex: The most effective wavelength of visible light in photosynthesis is in the region of
A) Violet
B) Green
C) Yellow
D) Red
Explanation: Blue and red regions of the light spectrum are the most effective in photosynthesis. Blue wavelengths of light carry more energy while red wavelengths have lesser energy. Therefore, the most efficient wavelengths of light effective in photosynthesis are those of light.
    2019-03-12 12:19:02.0
Ex: Which of the following when dissolved in water make(s) Bordeaux mixture
A) Copper sulphate
B) Calcium hydroxide
C) Both a and b
D) None of these
Correct answer: C
Explanation: Bordeaux mixture is prepared by dissolving copper sulphate, and calcium hydroxide in water.
    2019-03-11 11:41:08.0
Ex: Some protists possess structures for regulation of their water content. They are                                           
A) Nuclei                                       
B) Contractile vacuoles
C) Chromatophores                     
D) Membranes
Correct answer: B
Explanation: Contractile vacuole for regulation of water content are found in Paramecium, Amoeba etc.
    2019-03-08 11:41:44.0
Ex:  If an isolated strain of DNA is kept at 82−90C, then 
A) It changes into RNA
B) It divides into one million pieces
C) No effect
D) It uncoils into helixes
Correct answer: D
Explanation: The phenomenon of separating of two strand of DNA molecule by breaking of hydrogen bond at the temp 90oC.
    2019-03-07 12:34:47.0
Ex: Centromere is a part of chromosome which helps in the
A) Division of centrosomes
B) Formation of spindle fibres
C) Movement of chromosomes
D) Formation of nuclear spindle
Correct answer: C
Explanation: Centromere joins the microtubules of chromosomal spindle fibres and helps in the movement of chromosome during cell division. Centromere also plays an important role in the polymerization of tubulin protein used in the formation of microtubules. Hence it is helpful in attaching the chromosome with spindle fibres.
    2019-03-06 10:45:20.0
Ex: Plants requiring two metallic compounds (minerals) for chlorophyll synthesis, are
A) Fe and Ca
B) Fe and Mg
C) Cu and Ca
D) Ca and K
Correct answer: B
Explanation: Mg is a important constituent of chlorophyll molecule where it occupies a central position and essential for photosynthesis and Fe plays an important role in ETS, photosynthesis and respiration because iron is the part of cytochromes. It is also essential for chlorophyll synthesis.