Tag: biology

Questions Related to biology

Which of the following water comes under echards?

transpiration major activities of living organisms biology

  1. Available to the plant

  2. Whole of the soil water

  3. Amount of water not available to the plant

  4. None of the above

Show answer
Correct Option: C
Explanation:

Amount of water not available to plants is called as echard. It includes hygroscopic water and chemically bound water. 

Water present in the capillary spaces between soil particles is available to plants and is called as chresard. 
Whole water content of a field is called as hollard. It includes gravitational and surface run off water, chresard and echard water.

Plants growing on hills show?

transpiration major activities of living organisms biology

  1. Higher rate of transpiration

  2. Lower rate of transpiration

  3. Same rate of transpiration

  4. None of the above

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Correct Option: A

What is true for the water available in the soil?

transpiration major activities of living organisms biology

  1. Hollard = Chresard + Echard

  2. Hollard = Chresard Echard

  3. Chresard = Hollard + Echard

  4. Echard = Hollard + Chresard

Show answer
Correct Option: A
Explanation:

Amount of water not available to plants is called as echard. It includes hygroscopic water and chemically bound water. 

Water present in the capillary spaces between soil particles is available to plants and is called as chresard. 
Whole water content of a field is called as hollard. It includes gravitational and surface run off water, chresard and echard water.

A soil is said to be physiologically dry when

transpiration major activities of living organisms biology

  1. Soil is water logged

  2. Soil has high salt concentration

  3. Soil has low temperature

  4. All above cases prevail

Show answer
Correct Option: D
Explanation:

Physiologically dry soil means that water is present in the soil but is not available to the plants either because of high salt concentration, or lack of water in liquid form or poor aeration. These conditions respectively occur in saline marshes, cold deserts and water logged soil.

Arrange the following in descending order of volume: plasma, interstitial fluid, intracellular fluid.

transpiration major activities of living organisms biology

  1. $Intracellular \rightarrow Interstitial \rightarrow Plasma$

  2. $ Interstitial \rightarrow Intracellular \rightarrow Plasma$

  3. $Plasma \rightarrow Interstitial \rightarrow Intracellular$

  4. $Intracellular \rightarrow Plasma \rightarrow Interstitial $

Show answer
Correct Option: A
Explanation:

Volume of body fluids in a person of $70\,kg$ weight will be $42\,liter$, out of which intracellular fluid will be $28\,liter$, volume of interstitial fluid will be $11\,liter$ and plasma volume will be $3\,liter$.

The ion controlling stomatal movement is ____________.

transpiration major activities of living organisms biology

  1. $Na^+$

  2. $Ca^{2+}$

  3. $Mg^{2+}$

  4. $K^+$

Show answer
Correct Option: D

Which of the following processes keeps plant cool?

transpiration major activities of living organisms biology

  1. Transpiration

  2. Guttation

  3. Photosynthesis

  4. Translocation

Show answer
Correct Option: A
Explanation:

Transpiration keeps plant cool.

Cooling effect:
The leaves absorb the radiant energy. Some of the light energy is utilised in photosynthesis, rest is converted into heat energy resulting in an increase in leaf temperature. However, rapid loss of water in the form of water vapour from the aerial parts of the plant through transpiration brings down their temperature. Transpiration thus provides a significant cooling effect which keeps the plant from being over heated.

When the temperature of soil becomes $1^{\circ}$ $C$ then?

transpiration major activities of living organisms biology

  1. Absorption of water increases

  2. Absorption of water drecreases

  3. Absorption of water remain unaffected

  4. Both B and C are correct

Show answer
Correct Option: B
Explanation:

If the temperature of soil drops down drastically then absorption of water is decreased. This happens because one water starts changing its physical state from liquid to solid, so that passive absorption is decreased and the process of respiration stops at extreme temperatures. If respiration stops ATP will not be available for active absorption.

The chief role of transpiration in plants is to cause

transpiration major activities of living organisms biology

  1. Loss of surplus water

  2. Cooling of the plant

  3. Rapid ascent of sap

  4. Rapid rise of minerals

Show answer
Correct Option: B
Explanation:


Transpiration is the process by which plants throw out the extra water present in it. Since water is an essential ingredient in the survival of the plants, it is absorbed through the roots. However, only a small amount of water is taken up for the metabolic activity. The rest 90-95% water is thrown out through the process of transpiration. The stomata along with the guard cells present in the underside of the leaves help the plants to transpire.  The process of transpiration enables the mass flow of mineral and water from the roots to the shoots and thus maintains the osmotic pressure of the cells and cools the plants.

Day time loss of water in the vapour form from stomata is a trade off for intake of 

transpiration major activities of living organisms biology

  1. Minerals

  2. Oxygen

  3. Carbon dioxide

  4. Energy

Show answer
Correct Option: C
Explanation:

In the day-time, when photosynthesis occurs, the guard cells are turgid while in the evening, regardless of the availability of water, these guard cells lose turgidity. When they are turgid, stomata open, and carbon dioxide enters freely. When they are flaccid, carbon dioxide is largely excluded, but water loss is also retarded. hence, the daytime loss of water in the vapor form from stomata is a trade-off for intake of carbon dioxide.

Thus, the correct answer is option (C).