Tag: sense organs in humans

Questions Related to sense organs in humans

Phytohormones are

  1. Chemicals regulating flowering

  2. Chemicals regulating secondary growth

  3. Hormones regulating growth from seed to adulthood

  4. Regulators synthesised by plants and influencing physiological processes


Correct Option: D
Explanation:
Phytohormones are chemical substances synthesized by plants. 
These chemical substances regulate various physiological processes in plants.
So, the correct answer is 'Regulators synthesised by plants and influencing physiological processes'

Chemicals having profound effect on growth and development are

  1. Enzymes

  2. Phytohormones

  3. Catalytic agents

  4. Manure


Correct Option: B
Explanation:

Phytohormones are also called as plant hormones. These are chemicals which play important role in growth and development of plants. These are involved in various physiological processes of plants like growth, flowering, fruiting, shoot and root development, etc. Phytohormones liks auxin, cytokinin act as growth promoter whereas hormones like abscisic acid, ethylene act as growth inhibitor. 

Thus, the correct answer is option B.

Through their effect on phytohormones, temperature and light control

  1. Stomatal closure

  2. Apical dominance

  3. Flowering

  4. Fruit development


Correct Option: C
Explanation:

Phytohormone is the plant hormone that is involved in various processes of plants. Hormones like gibberellin induce flowering and abscisic acid inhibits flowering in plants. In plants, flowering is controlled by light and dark periods (photoperiod) and temperature in specific environments. Plant generally requires either long day or cold condition for flowering.

Thus, the correct answer is option C.

Phytohormone is a naturally produced organic substance in ________________.

  1. Higher plants which controls growth and development in general

  2. Plants to control growth and physiological functions at the site of its production

  3. Higher plants controlling growth and development at a site for removed from the site of its production and is effectively only when present in large quantities

  4. Higher plant controlling physiological and growth functions at a site quite removed form the site of its production and is effective when present when in minute quantities


Correct Option: A

High concentration of hormone will

  1. Kill the plant

  2. Cause chlorosis in leaves

  3. Cause stunting in plants

  4. Show no effect on the plant


Correct Option: C
Explanation:

When concentration of hormones in the plant body increases, growth of the plants decreases.

So, the correct option is cause stunting in plants’.

State whether the following statements are true or false.
A hormone is produced in small amounts in a tissue, and it causes a physiological action within that same tissue soon after its production.

  1. True

  2. False


Correct Option: B
Explanation:

A hormone is not produced in tissue but instead in an organ. The effect caused by that by that hormone can be seen in various parts of the body including the site of production. For example, insulin produced by pancreas converts the glucose present in the bloodstream into the glycogen.  

So, the correct option is 'False'.

Identify the physiological process induced by two phytohormones having a common precursor which is formed due to catalytic activity of pyruvic dehydrogenase complex
(a) More female flowers in Cucumber
(b) $\alpha$-amylase production in Barley grains
(c) Acceleration of fruit ripening in Tomato
(d) Delay in sprouting of Potato tubers.

  1. a, b

  2. a, c

  3. c, d

  4. b, d


Correct Option: C
Explanation:

Ethylene is a plant hormone. It accelerates fruit ripening in tomato. Maleic hydrazide is a type of auxin, plant hormone. It delays sprouting of potato tubers. Both these hormones have common precursor that is formed due to the catalytic activity of pyruvic dehydrogenase complex.

Thus, the correct answer is option C.

Receptors of pressure present in deep layers of skin are 

  1. Krause's end bulb

  2. Meissner's corpuscles

  3. Corpuscles of Ruffini

  4. Pacinian corpuscles


Correct Option: D
Explanation:

Meissner corpuscles are one of the three types of cutaneous receptors which are sensitive to fine touch. Three types are cutaneous receptors are sensitive to pressure which are namely Pacinian corpuscles, Ruffini endings and Krause end bulbs. Out of these, onion-shaped Pacinian corpuscles lie deep inside the dermis. The Ruffini endings are present deeper in epidermis near the base while the Krause end bulbs are present in specialized regions only, for example, conjunctiva of eyes, mucous membrane of lips and tongue etc. Thus, the correct answer is option D.

Tactile receptors in mammals are maximum on

  1. Body

  2. Limbs

  3. Face

  4. Head


Correct Option: C

Which of the following organ senses temperature?

  1. Tongue

  2. Nose

  3. Skin

  4. None of the above


Correct Option: C
Explanation:
  • Sensitivity to temperature is a skin sense that is related to the human need to maintain internal temperature balance or thermal homeostasis. 
  • When the body becomes hotter than the normal temperature the sweat glands releases sweat which in turns cools the skin as it evaporates. This helps the lower internal temperature of the body
  • Hence the organ which senses temperature is skin.
  • So, the correct answer is 'Skin'.