Tag: control and coordination in plants

Questions Related to control and coordination in plants

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

  1. Auxins

  2. Gibberellins

  3. Cytokine

  4. Ethylene


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.

  1. $1, 2$ and $3$

  2. $2, 3$ and $4$

  3. $1, 3$ and $4$

  4. $1, 2$ and $4$


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
  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-$2$


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
  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-$2$


Correct Option: A

Read the given statements and identify the  plant hormones X,Y and Z
i) Hormone Y includes flowering in mango
ii) Hormone X promotes root growth and root hair formation
iii) Hormone Z inhibits the speed germination,increases the tolerance of the plant to various stresses ,play important role in speed development, maturation and dormancy.

  1. Y : ABA X : ausin Z : GA

  2. Z : GA X : Auxin Z :C2H4

  3. Y : Auxin X : C2H4 Z : GA

  4. Y : C2H4 X : C2H4 Z : ABA


Correct Option: A

Match List I with List II and select the correct answer using the codes given the lists.

List-I List-II
a. Increase in wall elongation $1$. Gibberellins
b. Bolting and flowering $2$. Auxins
c. Cell division $3$. Absicsic acid
d. Dormancy $4$. Cytokinins
  1. A-$2$, B-$1$, C-$3$, D-$4$

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

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

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


Correct Option: A

The substance that triggers the fall of mature leaves and fruits from plants is

  1. Auxin

  2. Gibberellin

  3. Abscisic acid

  4. Cytokinin


Correct Option: C
Explanation:

Phytohormones are important plant growth regulators. The phytohormones, like auxins and gibberellins (GA), have positive growth-promoting effects whereas abscisic acid (ABA) and ethylene have growth inhibiting effects. Abscisic acid (ABA) was discovered for its role in regulating abscission and dormancy. It triggers fall of mature leaves and fruits from plants. Hence, it is called abscisic acid because of the formation of abscission layer which is responsible for fall of mature leaves and fruits from plants.  But like other PGRs, abscisic acid also has other wide-ranging effects on plant growth and development. It acts as a general plant growth inhibitor and an inhibitor of plant metabolism. ABA inhibits seed germination. ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kinds of stresses. Therefore, it is also called the stress hormone. ABA plays an important role in seed development, maturation and dormancy. By inducing dormancy, ABA helps seeds to withstand desiccation and other factors unfavorable for growth. In most situations, ABA acts as an antagonist to GAs.

Choose the correct answer from the alternatives given.
Which of the following statements about plant hormones is not true?

  1. Each naturally occurring hormone has a specific chemical structure

  2. Hormones are among the principal internal regulators of plant growth

  3. Responses to plant hormones may be observed in nearly any part of a plant

  4. All known growth regulators of plant activities are chemicals produced naturally in plants


Correct Option: D
Explanation:

Cytokinins have specific effects on cytokinesis and were discovered as kinetin (a modified form of adenine, a purine) from the autoclaved herring sperm DNA. Kinetin does not occur naturally in plants.

So, the correct option is 'All known growth regulators of plant activities are chemicals produced naturally in plants'.

Choose the correct answer from the alternatives given.
Plant hormones

  1. interact with one another

  2. are influenced by environmental cues

  3. are active in plant embryos within seeds

  4. all of the above


Correct Option: D
Explanation:

Plant hormones can work in combination and are dependent on the environmental cues or signals to act. They are also active in plant embryos within the seed such as Gibberellic acid.

So, the correct option is 'all of the above'.

Choose the correct answer from the alternatives given.
The mitotically active and hormone producing cells are:

  1. xylem

  2. meristem

  3. phloem

  4. cortex


Correct Option: B
Explanation:

Meristem is the actively dividing cells at the root and shoots apices that are mitotically active.

So, the correct option is 'meristem'.