261. The "Guttation " word was given by

A Bergerstein
B Sayer
C Scarth
D Stephen hales
Answer :   Bergerstein
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262. Criteria for essentiality in mineral nutrition were shown firstly by

A Arnon
B Liebig
C Steward
D Levitt
Answer :   Arnon
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263. The change in turgor pressure which causes the opening and closing of Stomata in caused by

A Reversible starch - sugar conversions
B Reversible absorption and loss of K-ions
C Loss of chloride ions
D None of the above
Answer :   Reversible absorption and loss of K-ions
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264. According to Scarth the opening & closing of stomata is governed by

A PH
B Phosphorylation
C NaDPH2
D Enzymes
Answer :   PH
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265. Transpiration and root pressure cause water to rise in plants by :

A Pulling and pushing it, respectively
B Pushing it upward
C Pushing and pulling it, respectively
D Pushing it upward
Answer :   Pulling and pushing it, respectively
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266. Due to more wind velocity, the transpiration rate will be

A Less
B More
C Unaffected
D First increases then decrease
Answer :   First increases then decrease
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267. The process involved in the formation of Toddy is

A Guttation
B Transpiration
C Bleeding
D All of the above
Answer :   Bleeding
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268. If is possible to drop a small particle through the stomata of leaf, what will you conclude

A It will on the earth surface
B It will stop on lower epidermis
C It will stop on mesophyll cells
D It will stop on vascular tissue
Answer :   It will stop on mesophyll cells
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269. With increase in the turgidity of a cell surrounded by water the wall pressure will

A increase
B decrease
C fluctuate
D remain unchanged
Answer :   increase
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270. A cell increases in volume if the external medium is

A Hypotonic
B Slightly hypertonic
C Isotoic
D Much more concentrated than the protoplasm of the cell
Answer :   Hypotonic
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