Tag: chemical coordination in plants

Questions Related to chemical coordination in plants

Leaf fall can be prevented with the help of 

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. Abscisic acid

  2. Auxins

  3. Florigen

  4. Cytokinins

Show answer
Correct Option: B
Explanation:

Leaf abscission is a detachment or fall of older leaves.It occurs at the base of the petiole. When auxin is applied to the base of petiole of young leaf, the abscission is greatly suppressed. Also, it is observed that the intact leaf does not fall off because it synthesizes auxin.

Thus, the correct answer is option B.

Which is not an influence of auxins?

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. Tropical movements

  2. Bolting

  3. Parthenocarpy

  4. Apical dominance

Show answer
Correct Option: B
Explanation:

Auxin is a plant hormone which is involved in various physiological processes. It is present on the tip of the stem and helps in phototropic movement in response to light. It also maintains apical dominance where there is more growth on the stem tip and growth of lateral bud is inhibited. Auxin along with cytokinin and gibberellin helps in the process of parthenocarpy. It does not cause bolting. It does not influence flowering in the plant.

Thus, the correct answer is option B.

Match the columns and find the correct combination:

      I             II
a Auxin 1. Herring sperm DNA
b Cytokinin 2. Inhibitor of growth
c Gibberellin 3. Apical dominance
d Ethylene 4. Epinasty
e Abscisic acid 5. Induces amylase synthesis
biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. a- 3, b- 1, c- 5, d- 4, e- 2

  2. a- 4, b- 5, c- 1, d- 3, e- 2

  3. a- 2, b- 1, c- 5, d- 3, e- 4

  4. a- 3, b- 1, c- 5, d- 2, e- 4

  5. a- 4, b- 1, c- 5, d- 3, e- 2

Show answer
Correct Option: A
Explanation:
Kinetin, a type of cytokinin was isolated from autoclaved herring sperm DNA. It has cell division-promoting activity. Auxin is a plant hormone. It promotes stem elongation and thus regulates apical dominance. Gibberellic acid is a plant hormone which breaks the dormancy. Before germination, it stimulates the synthesis of amylase enzyme. Amylase hydrolyzes starch into glucose which is used to provide nourishment to the seed embryo. Ethylene is a plant hormone that causes the downward bending of the plant part. This is called as epinasty. Abscisic acid is a plant hormone that acts as the inhibitor of growth.
Thus, the correct answer is option A.

Pick up correct statements.
(A) Cytokinins delay senescence
(B) Auxins regulate apical dominance
(C) Ethylene enhances seed germination
(D) Gibberellins cause falling of immature leaves

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. $a, c$

  2. $a, d$

  3. $a, b$

  4. $b, c$

  5. $b, d$

Show answer
Correct Option: C
Explanation:

Cytokinin is a plant hormone that promotes cell division. It delays senescence. Auxin promotes stem elongation and thus regulate apical dominance. Ethylene is also called as ripening hormone as it helps in the ripening of fruits. Gibberellic acid prevents falling of immature leaves. 

Thus, the correct answer is option C.

Match the columns and choose the correct combination.

Growth Regulator    Action
$(a)$ Abscisic acid $(1)$ Delays leaf abscission
$(b)$ Ethylene $(2)$ Inhibits seed germination
$(c)$ Cytokinin $(3)$ Herbicide
$(d)$ Auxin $(4)$ Hastens fruit ripening
biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. $a - 2, b - 4, c - 1, d - 3$

  2. $a - 1, b - 2, c - 3, d - 4$

  3. $a - 2, b - 3, c - 4, d - 1$

  4. $a - 2, b - 1, c - 3, d - 4$

  5. $a - 3, b - 4, c - 1, d - 2$

Show answer
Correct Option: A
Explanation:

Abscisic acid is a plant hormone. It is also called as stress hormone as its concentration increases during stress condition. During unfavorable environmental condition, it inhibits seed germination and induces seed dormancy. Ethylene is a plant hormone. It is also called as ripening hormone as it hastens fruit ripening in plants. Cytokinin is a plant hormone that induces cell division. It delays the abscission of leaves. A 2, 4-D is a synthetic auxin, a plant hormone. It acts as herbicide as it kills weeds.

Thus, the correct answer is 'a−2,b−4,c−1,d−3'.

Which of the following pairs are correctly matched?
a. Auxin- Dwarf rice
b. Gibberellin- Elongation
c. Cytokinin- Coconut milk
d. Abscisic acid- Early leaf fall.
Select the correct answer using the codes given.

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. $2, 3$ and $4$

  2. $1, 2$ and $3$

  3. $1, 2$ and $4$

  4. $1, 3$ and $4$

Show answer
Correct Option: A

Which one of the following classes of plant hormones is the substitute for low temperature treatment?

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. Auxins

  2. Gibberellins

  3. Cytokine

  4. Ethylene

Show answer
Correct Option: A

Which of the following chemicals are added in the synthetic media for culturing plant tissues?
a. Auxins
b. Cycloheximide
c. Cytokinins
d. Casein hydrolysate
Select the correct answer using the codes given.

biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

  1. $1, 2$ and $3$

  2. $2, 3$ and $4$

  3. $1, 3$ and $4$

  4. $1, 2$ and $4$

Show answer
Correct Option: A

In the context of rice diseases, match List-I with List-II using the codes given the lists.

List-I List-II
a. Helminthosporium oryzae $1$. Gibberella fujikuroi
b. Rhizoctonia solani $2$. Balanisa oryzae
c. Fusarium moniliforme $3$. Cochliobolus miyabeanus
d. Ephelis oryzae $4$. Corticium sasaki
biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

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

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

  3. A-$3$, B-$44$, C-$2$, D-$1$

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

Show answer
Correct Option: A

Match List I(Plant hormone) with List II(Typica physiological effect) and select the correct answer using the code given the lists.

List-I List-II
a. Auxin $1$. Apical dominance
b. Gibberellins $2$. Cell division
c. Cytokine $3$. Fruit ripening
d. Ethylene $4$. Internodes elongation
biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

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

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

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

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

Show answer
Correct Option: A