Nitrate reductase is an important enzyme for nitrate assimilation. Given below some regulation of nitrate reductase activity through phosphorylation and dephosphorylation.

a) Light, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby activates the enzyme

b) In Dark, and Mg2+ stimulate a protein kinase that phosphorylates the same serine residues, which then interact with a 14-3-3 inhibitor protein, and thereby inactivate nitrate reductase

c) In Light, and Mg2+ stimulate a protein kinase that phosphorylates the serine residues, and thereby activate nitrate reductase

d) In Dark, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby inactivates the enzyme

Which of the following statements about regulation of nitrate reductase is correct?

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#Question id: 37883

#Plant Biotechnology

Consider the following statements regarding the immobilization of plant cells:

A. Cells can be entrapped in membranes or stainless-steel screens.

B. Immobilization ensures that the cellular physiology remains exactly the same as in suspension cultures.

C. This technique is advantageous for biochemical production. 

D. Liquid medium is continuously run through the column to provide aeration and nutrients.

Which of the statements given above are correct?

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#Question id: 37884

#Plant Biotechnology

Statement I: Immobilization of cells often alters their cellular physiology compared to cells grown in suspension culture.

Statement II: Due to physiological changes, immobilized cell systems are widely preferred for all types of plant studies, including genetic and developmental studies.

Choose the correct answer:

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#Question id: 37885

#Plant Biotechnology

Assertion (A): Plant cell and tissue cultures can be maintained indefinitely.

Reason (R): Serial subculturing is performed to transfer tissues to fresh medium to counter nutrient depletion and medium drying.

Select the correct option:

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#Question id: 37886

#Plant Biotechnology

Column I (Hormone)	Column II (Function)
A. Auxin	1. Inhibition of leaf senescence
B. Cytokinin	2. Maturation of somatic embryo
C. Gibberellin (GA)	3. Inhibition of axillary bud outgrowth (Apical Dominance)
D. Abscisic Acid (ABA)	4. Fruit ripening
E. Ethylene	5. Release from dormancy (Seeds/Buds)

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#Question id: 37887

#Plant Biotechnology

Match the sucrose concentration in Column I with the type of vascular tissue favored in Column II.

Column I (Sucrose Conc.)	Column II (Differentiation Result)
A. 1%	1. Mostly Phloem
B. 2%	2. Both Xylem and Phloem
C. 2.5% – 3.5%	3. Little Xylem
D. 4%	4. Mostly Xylem

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#Question id: 37888

#Plant Biotechnology

Assertion (A): Tracheary element differentiation is considered an irreversible process. 

Reason (R): During differentiation, the cells lose their nuclei and cytoplasm, preventing dedifferentiation or redifferentiation.

Select the correct option: