Role of NPK

Q.

How do stomata open and close? Do they use receptor?

Q.

How does plant chromosomes gets separated without centriole? How spindle fibres are made in plant cell?

Q.

Deficiency symptom of nitrogen and potassium are visible first in_____.

Q. The element responsible for opening and closing of stomata is

1. boron
2. potassium
3. phosphorus
4. sodium

Q. Sir
How does mitosis occur in plants without centrioles and centrosomes. We are taught that spindle fibres are formed by centrioles moving to opposite poles of the cell and plant cells don't posses centrioles. Then how is the spindle apparatus is formed and constricted to divide the chromatids.

Q.

The wall of guard cells towards stomata are thin.

1. True
2. False

Q. Which of the following groups of elements are mobile?

1. $Fe,Ca,B$
2. $Ca,Mg,K$
3. $N,P,K$
4. $B,K,Ca$

Q.

Stoma opens when -

1)guard cell swell due to an increase in their water potential

2)guard cell swell by endosmosis due to influx of proton

3)guard cell swell by endosmosis due to efflux of potassium ion

4)guard cells swell due to a decrease in their water potential

Q. Which element is essential during cell division for the formation of mitotic spindle?

1. Phosphorus
2. Calcium
3. Nitrogen
4. Sodium

Q. The major role of phosphorus in plant metabolism is:

1. To generate energy metabolites
2. To evolve oxygen during photosynthesis
3. To evolve carbon dioxide during respiration
4. To create anaerobic conditions

Q.

What causes the opening and closing of stomata?

Q.

"Select the correct events leading to the opening of stomata:

I)decline in guard cell solutes

II) lowering of osmotic potential of guard cell

III) rise in potassium levels in guard cells

IV)movement of water from neighbouring cells to guard cells

V) guard cells becoming flaccid "

The answer to this question is given as II, III and IV

My doubt is why can it not be I, III and IV.

Because when there is a decline in guard cell solutes, it infers that there has been a movement of water from neighbouring cells to guard cells right?

Q.

Is phosphorus a trace mineral?

Q.

The element, _______________, is an important component of ADP and ATP.

1. phosphorus

2. potassium

3. chlorine

4. magnesium

Q. Select the correct option:
i. Potassium is absorbed as a divalent ion.
ii. Potassium is required in more quantities in meristematic tissues, buds, leaves, root tips.
iii. Potassium is found in 2 amino acids- cysteine & methionine.

1. Only i is correct
2. Only ii & iii are correct
3. Only i & ii are correct
4. Only ii is correct

Q. Match the following columns:
$\begin{array}{cc}Column-I& Column-II\\ \text{A. Nitrogen}& \text{1. Component of cell membrane}\\ \text{B. Phosphorus}& \text{2. Role in cell division}\\ \text{C. Potassium}& \text{3. Constituent of enzymes}\\ \text{D. Calcium}& \text{4. Involved in stomatal movement}\end{array}$

1. A - 2, B - 4, C - 2, D - 2.

2. A - 3, B - 1, C - 4, D - 2.

3. A - 4, B - 2, C - 3, D - 3.

4. A - 1, B - 3, C - 1, D - 1.

Q.

Which of the following macronutrients are required for the synthesis of nucleic acids?

1. Phosphorus, magnesium, nitrogen

2. Phosphorus, potassium, nitrogen

3. Nitrogen, magnesium, calcium

4. Phosphorous, nitrogen, sulphur

Q.

Calcium is an essential plant nutrient because it is a component of

1. chlorophyll

2. amino acids

3. ADP & ATP

4. cell walls

Q. Rubber band stretches and reverts back to its original position. Bubble gum stretches, but it would not return to its original position. Is there any difference between the two processes? Discuss it with respect to plant growth

Q.

Stomata of a plant open due to

1. influx of potassium ions

2. Efflux of potassium ions

3. Influx of calcium ions

4. Influx of hydrogen ions

Q. In succulent plants the stomata opens at night and closes by day. Which of the following would be best hypothesis to explain the mechanism of stomata opening at night only?

1. $C{O}_2$ used up, increased pH result in accumulation of sugar.
2. $C{O}_2$ accumulates, reduce pH stimulates enzymes resulting in accumulation of carbohydrate.
3. Increase in $C{O}_2$ concentration, conversion of organic acids into starch, resulting in the increased uptake of potassium ions and water.
4. High $C{O}_2$ concentration causes accumulation of organic aids in guard cells resulting into the increased concentration of cell sap.

Q. How do guard cells control opening and closing of stomata ?

Q. Match the columns and choose the correct combination.

	I(Essential Elements)		II(Deficiency Causes)
(a)	N, K, Mg, S, Fe, Mn, Zn and Mo	(i)	Inhibit cell division
(b)	N, K, S and Mo	(ii)	Necrosis
(c)	Ca, Mg, Cu and K	(iii)	Delay in flowering
(d)	N, S and Mo	(iv)	Chlorosis

1. a - iv, b - iii, c - ii, d - i
2. a - i, b - ii, c - iii, d - iv
3. a - ii, b - iii, c - iv, d - i
4. a - ii, b - iv, c - ii, d - i
5. a - iv, b - i, c - ii, d - iii

Q.

Deficiency symptoms of sulphur first appear in which part of leaf ?

Q. Match the following elements with their main functions:

1. Ionic balance
2. Amino acid synthesis
3. Root development

Q.

Diagram based questions

1. Name the structure in fig. A.
2. Label parts (i) and (ii).
3. Where is it present in a plant?

Q. Which of the following is a second messenger?

1. Sodium
2. Cyclic AMP
3. IP3
4. Both b and c

Q.

Suggest the theories to explain the changes that occur in the osmotic pressure of the guard cells during the mechanism of opening and closing of stomata.

Q. The major role of phosphorus in plant metabolism is:

1. To generate energy metabolites
2. To evolve oxygen during photosynthesis
3. To evolve carbon dioxide during respiration
4. To create anaerobic conditions

Q. In guard cells, when sugar is converted into starch, the stomatal pore

1. Remains unchanged
2. Opens fully
3. Closes completely
4. Opens partially