Biology

Plant Transport and Physiology

2,012 Questions

Access a comprehensive set of questions on plant transport mechanisms and physiological adaptations. Topics include water movement, translocation of food, and plant responses to external stimuli. These biology questions are essential for medical entrance exams and other science competitive tests.

Xylem and phloem transportTranspiration and evaporationPlant adaptationsGeotropic and phototropic responsesWater absorption by rootsRespiration in roots

Plant Transport and Physiology Questions

Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

The stem of the plant when cut and dipped in the water helps in the transport of 

  1. Water

  2. Minerals

  3. Food

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Stem contains special complex permanent tissues called xylem. The xylem helps in the conduction and transportation of water in one direction that is from stem to leaves. 

So the correct option is 'Water and minerals'.

Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

The water and minerals are conducted by the stem to which part/s of the plant?

  1. Leaves

  2. Flowers

  3. Buds

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Stem conducts the water and minerals from the root at the site of absorption to the leaves and other parts of a plant with the help of vascular bundles called xylem.
So, the correct option is 'All of the above'
Multiple choice biology types and parts of plants leaves root, stem, and leaves basics of roots and stem

The stem was cut and dipped in water and red ink and colour of the leaves became red due to 

  1. The absorption of red ink by the leaves from the water

  2. The conduction of water and ink by the stem

  3. The loss of green colour from the leaves

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This experiment is done to check the movement of water in stem in which ink is mixed with water and the stem is left in the mixture and after an hour we observe the stem and it shows that the ink is present inside the stem shows that the stem conducted the water and the ink, as well as the colored ink patches, are observing it proves that  the xylem and its elements help stem to conduct the water.

So the correct option is 'The conduction of water and ink by the stem'

Multiple choice transpiration major activities of living organisms biology

Transpiration is least in?

  1. Good soil moisture

  2. High wind velocity

  3. Dry environment

  4. High atmosphere Humidity
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Loss of water in the form of water vapour through the aerial parts of the plant body is called Transpiration. The transpiration rate falls as the relative humidity of the air around the plant increases.
So, the correct option is 'High atmosphere Humidity'.
Multiple choice transpiration major activities of living organisms biology

Which of the following water comes under echards?

  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice transpiration major activities of living organisms biology

Plants growing on hills show?

  1. Higher rate of transpiration

  2. Lower rate of transpiration

  3. Same rate of transpiration

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plants on hills are exposed to higher wind speeds and lower atmospheric pressure, both of which increase the rate of evaporation and thus the rate of transpiration.

Multiple choice transpiration major activities of living organisms biology

The ion controlling stomatal movement is ____________.

  1. $Na^+$
  2. $Ca^{2+}$
  3. $Mg^{2+}$
  4. $K^+$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The accumulation of potassium ions (K+) in guard cells lowers their water potential, causing water to enter by osmosis, which leads to the opening of stomata.

Multiple choice transpiration major activities of living organisms biology

Which of the following processes keeps plant cool?

  1. Transpiration

  2. Guttation

  3. Photosynthesis

  4. Translocation
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

Multiple choice transpiration major activities of living organisms biology

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

  1. Absorption of water increases

  2. Absorption of water drecreases

  3. Absorption of water remain unaffected

  4. Both B and C are correct
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice transpiration major activities of living organisms biology

The chief role of transpiration in plants is to cause

  1. Loss of surplus water

  2. Cooling of the plant

  3. Rapid ascent of sap

  4. Rapid rise of minerals
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice transpiration major activities of living organisms biology

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

  1. Minerals

  2. Oxygen

  3. Carbon dioxide

  4. Energy
Reveal answer Fill a bubble to check yourself
C Correct answer
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). 

Multiple choice transpiration major activities of living organisms biology

Which of the following is not the purpose of transpiration process?

  1. Supplying water for photosynthesis

  2. Maintaining shape and structure of plants

  3. Translocation of sucrose from source to sink

  4. Cooling the leaf surfaces
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiration is the process of loss of water through the aerial parts of the plant. It depends upon the amount of humidity level of the atmosphere.

When there is a high level of moisture then there is no concentration gradient between leaf and the atmosphere there is a minimum loss of water through transpiration. 
So, the correct answer is 'Translocation of sucrose from source to sink'.