Class XI & XII · Biology practice
Botany PYQs Check your understanding, bookmark questions and revisit your mistakes.
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408 questions in this collection · Page 19 of 41
Cell Cycle And Cell Division
Dissolution of the synaptonemal complex occurs
during:
A Pachytene B Zygotene C Diplotene D Leptotene
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Cell Cycle And Cell Division
Match the following with respect to meiosis :
(A)Zygotene
(I)Terminalization
(B)Pachytene
(II)Chiasmata
(C)Diplotene
(III)Crossing over
(D)Diakinesis
(IV)Synapsis
Select the correct option from the following :
A (A)-(III), (B)-(IV), (C)-(I), (D)-(II) B (A)-(IV), (B)-(III), (C)-(II), (D)-(I) C (A)-(I), (B)-(II), (C)-(IV), (D)-(III) D (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
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Transport In Plants
The process responsible for facilitating loss of water in liquid form from the tip of grass blades at night and in early morning is:
A Transpiration B Root pressure C Imbibition D Plasmolysis
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Transport In Plants
Select the incorrect statement.
A Transport of molecules in phloem can be
bidirectional. B Movement of minerals in xylem is unidirectional. C Unloading of sucrose at sink does not involve the
utilization of ATP. D Elements most easily mobilized in plants from one
region to another are: phosphorus, sulphur, nitrogen and potassium.
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Mineral Nutrition
Match the following concerning essential elements
and their functions in plants:
(A)Iron
(I)Photolysis of water
(B)Zinc
(II)Pollen germination
(C)Boron
(III)Required for chlorophyll biosynthesis
(D)Manganese
(IV)IAA biosynthesis
Select the correct option:
A (A)-(II), (B)-(I), (C)-(IV), (D)-(III) B (A)-(IV), (B)-(III), (C)-(II), (D)-(I) C (A)-(III), (B)-(IV), (C)-(II), (D)-(I) D (A)-(IV), (B)-(I), (C)-(II), (III)
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Mineral Nutrition
The product(s) of reaction catalyzed by nitrogenase in root nodules of leguminous plants is/are:
A Ammonia alone B Nitrate alone C Ammonia and oxygen D Ammonia and hydrogen
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Mineral Nutrition
In Glycine max, the product of biological nitrogen fixation is transported from the root nodules to other parts as:
A Ammonia B Glutamate C Nitrates D Ureides
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Photosynthesis In Higher Plants
In light reaction, plastoquinone facilitates the
transfer of electrons from:
A PS-II to Cytb6 f complex B Cytb6 f complex to PS-I C PS-I to NADP+ D PS-I to ATP synthase
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Photosynthesis In Higher Plants
The oxygenation activity of RuBisCo enzyme in
photorespiration leads to the formation of:
A 2 molecules of 3-C compound B 1 molecule of 3-C compound C 1 molecule of 6-C compound D 1 molecule of 4-C compound and 1 molecule of 2-C compound
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Photosynthesis In Higher Plants
Which of the following statements is incorrect?
A RuBisCO is a bifunctional enzyme B In C4 plants, the site of RuBisCO activity is mesophyll cell C The substrate molecule for RuBisCO activity is a 5-carbon compound D RuBisCO action requires ATP and NADPH
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AI-generated explanation. Check against your textbook.
Explanation: Option 2 is incorrect because in C4 plants, RuBisCO is active mainly in bundle sheath cells, not in mesophyll cells. In C4 photosynthesis, CO2 is initially fixed in mesophyll cells into a 4‑carbon compound, which is then released to bundle sheath cells where RuBisCO fixes CO2 in the Calvin cycle.
🧠 Did You Know? RuBisCO is a bifunctional enzyme—it can act as both a carboxylase and an oxygenase, catalyzing CO2 fixation as well as O2 reaction with RuBP.
💡 NCERT Memory Line: RuBisCO fixes CO2 in the Calvin cycle; ATP and NADPH are used in regenerating RuBP, not in the direct carboxylation step by RuBisCO.
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