Tag: biology

Questions Related to biology

Which of the following is/are the secretion/s of Adrenal gland?

biology control and co-ordination in plants and animals control of blood glucose hormones in human reproduction testes and ovary

  1. Cortisone

  2. Nor-epinephrine

  3. Adrenaline

  4. All of the above

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Correct Option: D
Explanation:

All the mentioned are the secretions of the adrenal gland.

Growth Hormone is secreted by

biology control and co-ordination in plants and animals control of blood glucose hormones in human reproduction testes and ovary

  1. Pineal Body

  2. Pituitary Gland

  3. Pancreas

  4. Parathyroid Gland

Show answer
Correct Option: B
Explanation:
Growth hormone (GH), also called somatotropin or human growth hormone, peptide hormone secreted by the anterior lobe of the pituitary gland. It stimulates the growth of essentially all tissues of the body, including bone.

Delaying aging of leaves and opening of stomata are due to the action of _______

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Auxins 

  2. Gibberellins

  3. Cytokinins

  4. Abscisic acid

Show answer
Correct Option: C
Explanation:
A. Auxins are the plant hormones which promote cell enlargement and cell differentiation. It also promote fruit growth. It is responsible for phototropic and geotropic responses of plants.
B. Gibberellins are plant hormones which promote cell enlargement and cell differentiation in the presence of auxins. It help in breaking the dormancy in seeds and buds. It also promote fruit growth. It stimulates elongation of shoots of various plants.
C. Cytokinins are plant hormones which promote cell division in plants. It also helps in breaking the dormancy in seeds and buds. The delay the ageing of leaves. It promotes opening of stomata.
D. Abscisic acid (ABA) is a  plant hormone which functions mainly as a growth inhibitor. It promotes the dormancy in seeds and buds [ this is the opposite of breaking the dormancy. It also promotes closing of stomata. It promotes falling of leaves. 
So, the correct answer is 'Cytokinins'.

Cytokinins are known to

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Inhibit cytoplasmic movement.

  2. Help in retention of chlorophyll.

  3. Influence water movement.

  4. Promote abscission layer formation.

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Correct Option: B
Explanation:

Cytokinins perform several other functions:
- Stimulates cell division.
- Stimulates morphogenesis in tissue culture.
- Stimulates the growth of lateral buds.
- Stimulates leaf expansion.
- Enhance stomatal opening

Cytokinin and ethylene have oppsite effect on:-

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Leaf senescence

  2. Elogation of stem

  3. Lateral swelling of stem

  4. Winter dormancy

Show answer
Correct Option: A
Explanation:

Cytokinins are the plant hormones that are responsible for cell division and elongation, their help in the delay of leaf senescence as they transport nutrients to these parts. Ethylene is a gaseous hormone and is responsible for transverse growth as swelling of the stem, It hastens the senescence of leaves due to the evolution of ethylene gas.

So, the correct option is 'Leaf senescence'.

Find the correct application of cytokinin.

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Acts as anti-transparent and induces closure of stomata

  2. To promote root development on various types of cuttings

  3. In tea plantation for giving bushy appearance

  4. Promotes parthenocarpy in fruits like banana and grapes

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Correct Option: A

Kinetin was first isolated and identified by

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Charles Darwin

  2. Boysen and Jansen

  3. Paal

  4. Miller

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Correct Option: D
Explanation:

Kinetin is a type of cytokinin, a class of plant hormone that promotes cell division. Kinetin was originally isolated by Miller and Skoog et al., as compound from autoclaved herring sperm DNA that had cell division-promoting activity.

The chief role of CK is 

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. To check abscission

  2. To check senescence

  3. To mobilize solutes

  4. To check senescence and to mobilize solutes from one part to other

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Correct Option: D
Explanation:

Cytokinin hormone does the major function of checking senescence and mobilising solutes from one part to another. It promotes the cell division or cytokinesis, in plant roots and shoots.

So, the correct answer is option D.

Phytocytomine is a

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Kinetin

  2. Giberellin

  3. Auxin

  4. None of the above

Show answer
Correct Option: A
Explanation:

Phytocytomine is a plant growth regulator. It is a kind of kinetin. It is synthesized from Licheniformis bacillus.

Which of the following contains cytokinin?

biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

  1. Coconut milk

  2. Young kernels of maize

  3. Fruit of cucurbits

  4. Both (A) and (B)

Show answer
Correct Option: D
Explanation:

Coconut milk and young kernels of maize contains cytokinin. Cytokinis are a class of plant growth substances that promote cell division, or cytokinesis in plant roots and shoots. It is an adenine derivative.