Tag: biology

Questions Related to biology

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

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.

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. 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

Show answer
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
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-$1$, 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-$4$

Show answer
Correct Option: A

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

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. Auxin

  2. Gibberellin

  3. Abscisic acid

  4. Cytokinin

Show answer
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?

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. 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

Show answer
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'.