15. Mycorrhizae are symbiotic associations between
A.algae and fungi
B.root and fungi
C.bacteria and root
D.bacteria and fungi

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16. The proteins that forms the walls of the microtubules are
A.actin
B.tubulin
C.pectin
D.hydroxyproline

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17. The colour of flower is due to the presence of
A.chlorophyll
B.xanthophylls
C.florigen
D.chromoplast or anthocyanin

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18. What are the names of the two genders of haploid yeast cells?
A.A and Alpha
B.M and F
C.Y(a)and Y(b)
D.None of these

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19. Neurospora is used as an experimental tool in
A.ecology
B.cytology
C.genetics
D.physiology

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20. The volume of O2 liberated in photosynthesis has which of the following ratio to CO2?
A.1:1
B.2:1
C.1:2
D.3:1

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21. Rice can grow in water submerged soil because the plants
A.have spongy roots
B.can oxidize the micro-environment around their roots and thus able to absorb oxygen
C.are adapted to enable roots to ward off toxic products
D.all of the above

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