Tag: plant growth

Questions Related to plant growth

Find out correct options.

   I      II      III
a Foolish plant p Volatile hormone x Induces dormancy
b Induces senescence q Abscisic acid y Ripens fruit
r Gibberella z Usually sterile plant
biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. a- p- y, b- r- x

  2. a- r- z, b- q- z

  3. a- r- z, b- p- y

  4. a- q- x, b- r- y

Show answer
Correct Option: B
Explanation:

The foolish seedling disease affects the rice plant through the roots or crowns. It is caused by the fungus Gibberella fujikuroi. It is the source of gibberellin hormone. The plant is usually sterile. Abscisic acid is a plant hormone that induces senescence in plants. Under stress environmental condition, it induces seed dormancy.

Thus, the correct answer is option B.

The primary and secondary growth of a shoot is inhibited by

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Auxin

  2. Gibberellin

  3. Cytokinin

  4. Abscisic acid

Show answer
Correct Option: D
Explanation:

Abscisic acid is a plant hormone. It is growth inhibitor hormone. Its primary role is inhibition of growth of root, shoot, leaf, etc. It inhibits primary and secondary growth of shoot. During stress condition, its concentration increases.

Thus, the correct answer is option D.

Which one is derivative of a carotenoid?

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. IAA

  2. ABA

  3. IBA

  4. GA

Show answer
Correct Option: B
Explanation:

Abscisic acid is plant hormone. It is terpenoid chemically, that is derivative of carotenoid. It stimulates seed dormancy in plants. Carotenoids are also called as tetraterpenoids.

Thus, the correct answer is option B.

State whether the following statements are true or false.
A cut woody stem exposed to a cytokinin solution will be induced to grow roots rapidly.

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

cytokinins are the plant growth regulators that promote cell division, they function similar to auxin and helps in cell elongation and are majorly present in the roots and then passes through the xylem. They perform many functions like cell division, embryo and endosperm formation, and growth of root cells etc.

So, the correct statement is 'True'.

Kinetin, a modified form of adenine was discovered from

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Autoclaved herring sperm DNA

  2. Coconut milk

  3. Corn kernel

  4. Fungus

Show answer
Correct Option: A
Explanation:

Kinetin is a modified form of adenine which is discovered by Miller and Skoog as a compound from autoclaved herring sperm DNA. Herring is a fish. From it's sperm, DNA is isolated which is sterilized using steam at high pressure which is called autoclaved herring sperm DNA. From this, kinetin was isolated which has ability to induce cell division.

Thus, the correct answer is 'Autoclaved herring sperm DNA.'

Horizontal growth of seedlings, swelling of axis and apical hook formation in dicot seedlings is brought about by

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Auxins

  2. Gibberellins

  3. Ethylene

  4. Kinetin

  5. Abscisic acid

Show answer
Correct Option: C
Explanation:
Ethylene is a gaseous plant hormone. It is also called as ripening hormone as it stimulates ripening of fruits. It also promotes the horizontal growth of seedlings, swelling of the axis and increase curvature by apical hook formation in dicot seedlings. It inhibits stem elongation. This is called as triple response shown by ethylene.
Thus, the correct answer is option C.

Which is not the effect of ethylene?

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Promotes senescence and abscission of plant organs

  2. Breaks seed and bud dormancy

  3. Brings about horizontal growth of seedlings

  4. Hastens fruit ripening

  5. Helps to overcome apical dominance

Show answer
Correct Option: E
Explanation:

Ethylene is a plant hormone. It is also called as ripening hormone as it hastens fruit ripening in plants. In certain plants, it breaks seed and bud dormancy and induces germination. It also causes flowers to fall from the plant and hence, promotes senescence and abscission of plant hormones. It also causes the triple response in etiolated seedlings. It inhibits stem elongation and brings about the horizontal growth of seedlings. 

Thus, the correct answer is option E.

Ethylene promotes water absorption by increasing the root's absorption surface. It promotes:

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Premability of cell membrane

  2. Rormation of root hairs

  3. Concentration of cell sap

  4. All of these

Show answer
Correct Option: D
Explanation:
Ethylene promotes water absorption by increasing the root's absorption surface. It promotes the elongation of the root hairs and the root itself and it is also responsible for increasing the cell permeability in some cases. It has also been observed to increase the osmotic pressure and the concentration of cell sap.

So, the correct answer is 'all of these'.

Artificial ripening of fruit is carried out by

biology plant growth other plant hormones cytokinins, ethylene and abscisic acid plant hormones

  1. Auxin

  2. Gibberellin

  3. Abscisic acid

  4. Ethylene

Show answer
Correct Option: D
Explanation:

Ethylene is sprayed on fruits to promote artificial ripening, which is very commonly seen in fruit shops.
Ethylene is applied on fruits in the form of a spray. It acts to the fruit cell wall made of pectin or cellulose and promotes ripening.

Match the Column-I & Column-II.

(i) Auxin (A) Ripening of fruit
(ii) ABA (B) Bolting
(iii) Gibberellin (C) Sensitivity against adverse conditions
(iv) Ethephon (D) parthenocarpy in tomato
biology plant growth control of blood glucose hormones in human reproduction testes and ovary

  1. i-C, ii-D, iii-B, iv-A

  2. i-D, ii-C, iii-A, iv-B

  3. i-D, ii-C, iii-B, iv-A

  4. i-A, ii-C, iii-B, iv-D

Show answer
Correct Option: C
Explanation:

  • (i) Auxin - (D) parthenocarpy in tomato -Auxins are generally produced by the growing apices of the stems and roots, from where they migrate to the regions of their action. Auxins also induce parthenocarpy in
tomatoes. 
  • (ii) ABA - (C) Sensitivity against adverse conditions -ABA(Abscisic acid) acts as a general plant growth inhibitor and an inhibitor of plant metabolism.ABA regulates sensitivity against adverse conditions i.e ABA stimulates the closure of stomata in the epidermis and increases the tolerance of plants to various kind of stresses. Therefore, it is also called the stress hormone.
  • (iii) Gibberellin - (B) Bolting -Gibberellins promotes bolting
(internode elongation just prior to flowering) in beet, cabbages and many
plants with rosette habit.
  • (iv) Ethephon - (A) Ripening of fruit - Ethephon in an aqueous solution is readily absorbed and transported within the plant and releases ethylene slowly. Ethephon hastens fruit ripening in tomatoes and apples.
  • So, the correct answer is 'i-D, ii-C, iii-B, iv-A'.