Tag: transport in plant

Questions Related to transport in plant

During absorption of water by roots, the water potential of cell sap is lower than that of

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Pure water and soil solution

  2. Neither pure water nor soil solution

  3. Pure water but higher than that of soil solution

  4. Soil solution but higher than that of pure water

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Correct Option: A
Explanation:

Water flows from higher water potential to lower water potential. Water potential of pure water is zero. As solutes are dissolved in it, the water potential decreases. More the dissolved solutes, lower will be the water potential. Water potential of all the solutions is always negative. Hence, water flows from higher water potential (i.e., less negative water potential) towards a lower water potential (i.e., more negative water potential). It is clear that absorption of water will occur if water potential of cell sap is lower than pure water and soil solution.

Which of the following statement(s) is/are incorrect?

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Water and salts are taken simultaneously by root hairs.

  2. Plants absorb one thing at a time either water or inorganic salt.

  3. Plants absorb excess quantity of water.

  4. All of the above.

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Correct Option: B
Explanation:

It is wrong to believe that water absorption and absorption of mineral salts are two unrelated processes. In fact the active uptake of ions is partly responsible for the water potential gradient in roots, and therefore for the uptake of water by osmosis. Some ions also move into the epidermal cells passively. Since soil has less concentration of minerals; most of the minerals are absorbed actively.

When concentration of solutes is low in the soil, absorption of water is 

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Stopped

  2. Increased

  3. Retarded

  4. Normal

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Correct Option: B
Explanation:

Roots absorp water from soil through diffusion process. Diffusion occurs in the presence of  concentration gradient. When amount of solute is less in soil solution then amount of water is more in soil solution. In this condition more amount of water will diffuse from soil to roots that's why water absorption is increased.

Lignin and cellulose have affinity for water. This is called

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Adhesion

  2. Cohesion

  3. Root pressure

  4. None of the above

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Correct Option: A
Explanation:

  • The attraction between the molecules of dissimilar substances is termed as adhesion. 
  • Walls of tracheid and vessels of xylem are made up of lignin and the cellulose. Hence due to the adhesive force, they have a close affinity for water.
  • So, the correct answer is option A.

A water-logged soil is physiologically dry because of

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Anaerobic conditions

  2. Non movement of water capillaries

  3. Increased viscosity of water

  4. Abundance of salts

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Correct Option: A
Explanation:

Water-logging indicates to the concentration of soil with water. When the soil is saturated with water over the course of time leads to blockage of air phases and anaerobic condition is succeeded, now the soil may be regarded as waterlogged. In the intense condition (physiologically dry) continued waterlogging leads to anaerobiosis (life sustaining by organism in the absence of oxygen), mostly occurs to mesophytes roots, denitrification and methanogenesis due to reduced atmosphere. 

So, the correct answer is option A.

Root hair absorbs water from soil through

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Turgor pressure

  2. Ion exchange

  3. Osmosis

  4. DPD

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Correct Option: C
Explanation:

Root hair absorbs water from soil through osmosis. Water will be absorbed by root hairs by osmosis as the environment in the soil is hypotonic. This kind of absorption takes place passively. The water can easily move from the region of higher concentration to the low concentration without expenditure of energy. The cell membrane of the root cells acts as a semipermeable membrane. It passes the epidermis, cortex, endodermis, casparian strip and pericycle and protoxylem and metaxylem.

So, the correct answer is option C.

Loss of water taken place through.

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Stomata, cell wall of mesophyll cells and hydathodes

  2. Stomata and cell wall of mesophyll cells

  3. Stomata and hydathodes

  4. Cell wall of mesophyll cells and hydiahodes

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Correct Option: A

Whose water potential is less than water potential of root hair during water absorption (by root hair)?

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Gravitational water

  2. Pure water

  3. Vacuolar sap

  4. Soil solution

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Correct Option: C

Match List I with List II and select the correct answer using the codes given the lists.

List-I(significance of the phenomenon in cell-water relations) List-II(Quantity)
a. Degree of hydration of protoplasm $1$. Wall pressure
b. Stretches cell walls and may lead to their enlargement if the walls are sufficiently plastic $2$. Water potential
c. Increases the free energy of water molecule $3$. Turgor pressure
d. Indicates the direction of diffusion of water $4$. Osmotic potential
biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. A-$1$, B-$3$, C-$2$, D-$4$

  2. A-$4$, B-$3$, C-$1$, D-$2$

  3. A-$4$, B-$1$, C-$2$, D-$3$

  4. A-$3$, B-$4$, C-$2$, D-$1$

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Correct Option: A

Rate of water absorption can be increased through 

biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

  1. Decreased transpiration

  2. Decreased ion absorption

  3. Increased photosynthesis

  4. Increased transpiration

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Correct Option: D
Explanation:
The rate of transpiration is high on a bright sunny day. The water is lost from guard cell which leads to decrease in the water potential of guard cell as compared to the surrounding cell. To stabilize the water potential in the guard cell water rushes from the neighbouring cell which creates a cohesion pull in the xylem vessels to pull the water up to the guard cell. Thus, the rate of water absorption increases when the transpiration is high. 
So, the correct answer is option D.