Plant Growth Regulators

Q.

One hormone hastens maturity period in juvenile conifers, second hormone controls xylem differentiation, while the third hormone increases the tolerance of plants to various stresses. They are respectively

1. Gibberellin, Auxin, Ethylene

2. Auxin, Gibberellin, Cytokinin

3. Gibberellin, Auxin, ABA

4. Auxin, Gibberellin, ABA.

Q. Select the pair that consists of plant growth promoter only.

1. Auxins and cytokinins
2. Gibberellins and ABA
3. Ethylene and ABA
4. All of these

Q. Which of the following is not a growth-promoting activity in plants?

1. Formation of flowers in plants
2. Formation of seeds in plants
3. Response of plant towards a wound
4. Pattern formation in plants

Q. Which of the following plant growth regulators is gaseous in nature?

1. Ethylene
2. Abscisic acid
3. Indole acetic acid
4. Cytokinin

Q. Which of the following is NOT an auxin?

1. IAA
2. IBA
3. Zeatin
4. NAA

Q.

Match the following columns.
$\begin{array}{cccc}& \text{Column I}& & \text{Column II}\\ \text{A}& \text{Zeatin}& 1& \text{Flowering hormone}\\ \text{B}& \text{Florigen}& 2& \text{Synthetic auxin}\\ \text{C}& \text{IAA}& 3& \text{Cytokinin}\\ \text{D}& \text{NAA}& 4& \text{Natural auxin}\end{array}$

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

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

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

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

Q. Which of the following is/are true for plant growth regulators?

1. Plant growth regulators are also known as phytohormones.
2. The regulators are signal molecules produced within the cell.
3. They occur in extremely low concentrations.
4. Phytohormones are required in high concentrations.

Q.

Match the following columns
$\begin{array}{cccc}& ColumnI& & ColumnII\\ A.& Humanurine& 1.& Cytokinin\\ B.& Gibberellafujikuroi& 2.& Auxin\\ C.& HerringfishDNA& 3.& Ethylene\\ D.& Ripeningoffruits& 4.& Abscisicacid\\ E.& Agedleavesofplants& 5.& Gibberellins\end{array}$

1. (A)→(2), (B)→(5), (C)→(1), (D)→(3), (E)→(4)

2. (A)→(2), (B)→(3), (C)→(4), (D)→(5), (E)→(1)

3. (A)→(1), (B)→(5), (C)→(2), (D)→(4), (E)→(3)

4. (A)→(5), (B)→(4), (C)→(3), (D)→(2), (E)→(1)

5. (A)→(3), (B)→(2), (C)→(1), (D)→(5), (E)→(4)

Q. Thin filament of myofibril contains 2 F actins and two other proteins namely .......... and ...........

Q. Match the following.
Diverse class of organic compounds Plant growth regulators

1) Indole compounds	i) Abscisic acid
2) Derivatives of carotenoids	ii) Ethylene
3) Terpenes	iii) IAA
4) Gases	iv) Gibberellic acid

1. 1-iii, 2-i, 3-iv, 4-ii
2. 1-ii, 2-i, 3-iv, 4-iii
3. 1-i, 2-iii, 3-iv, 4-ii
4. 1-iii, 2-i, 3-ii, 4-iv

Q.

Woulda defoliated plant respond to photoperiodic cycle? Why?

Q. Distinguish cytokinesis from karyokinesis.

Q.

List five main groups of natural plant growth regulators. Write a note on discovery, physiological functions and agricultural/horticultural applications of any one of them.