Tag: transport in plant

Questions Related to transport in plant

Scum float on the surface of water because 

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

  1. The density of cell is more than that of water

  2. Oxygen accumulate in it

  3. Carbon dioxide accumulate in it

  4. It generates methane gas

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Correct Option: A

Select the correct sequence of passive absorption path of water in a plant

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

  1. Soil $\rightarrow $ Root hair $\rightarrow $ Epidermis $\rightarrow $ Secondary cortex $\rightarrow $ Endodermis $\rightarrow $ Pericycle $\rightarrow $ Metaxylem

  2. Soil $\rightarrow $ Root hair $\rightarrow $ Cortex $\rightarrow $ Passage cells $\rightarrow $ Pericycle $\rightarrow $ Root protoxylem $\rightarrow $ Root Metaxylem

  3. Soil $\rightarrow $ Epidermis $\rightarrow $ Cortex $\rightarrow $ Endodermis $\rightarrow $ Pericycle $\rightarrow $ Root metaxylem $\rightarrow $ Root protoxylem $\rightarrow $ Root hair

  4. Soil $\rightarrow $ Epidermis $\rightarrow $ Cortex $\rightarrow $ Pericycle $\rightarrow $ Endodermis $\rightarrow $ Root protoxylem

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Correct Option: A
Explanation:
Option (A)
Soil $\rightarrow$ Root hair $\rightarrow$ Epidermis $\rightarrow$ Secondary cortex $\rightarrow$ Endodermis $\rightarrow$ Pericycle $\rightarrow$ Metaxylem.
The absorption of water by plants is essential for various metabolic activities. Soil water enters into the cortical cells through root hairs to reach the xylem of roots to maitain the supply of water.

Suitable temperature for active absorption of water by root is

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

  1. $40\, -\, 45^{\circ} C$

  2. $10\, -\, 15^{\circ} C$

  3. $20\, -\, 35^{\circ} C$

  4. Can take at any temperature

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Correct Option: C
Explanation:

Active absorption requires input of energy, which is obtained from cellular respiration. Respiration is an enzymatic process and is inhibited at extreme temperatures. Hence, the optimum temperature for active absorption is twenty to thirty five degree celsius.

At low temperature water absorption decreases due to
(I) An increase in the viscosity of water and protoplasm. 
(II) A decrease in the permeability of cell membranes.
(III) A decrease in the metabolic activities of root cells. 
(IV) A check in the growth and elongation of roots.

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

  1. I and II are correct

  2. I and III are correct

  3. I, II and III are correct

  4. All are correct

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Correct Option: D
Explanation:

At low temperature, there will be physical changes in water and also water absorption, both due to active and passive means will decrease. There will be an increase in viscosity of water and decrease in respiration in roots. The decreased respiration will lead to reduced supply of ATP. Hence, active absorption will decrease. Also, growth of roots will suffer due to decrease in rate of metabolism. The cell membrane will become less permeable and there will be lesser movement of solutes across them. As temperature rises, the lipids become more fluidic and permit movement of more solutes across the membrane.

In poorly aerated soil, the rate of water absorption will

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

  1. Increase

  2. Decrease

  3. Remains the same

  4. None of the above

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Correct Option: B
Explanation:

Poorly aerated soil, particularly when it is deficient in oxygen, retards absorption of water from the soil. Accumulation of $CO _2$ in the soil also inhibits absorption.

Root cap plays no role in the absorption of water in a plant, because

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

  1. Its cells are loosely arranged.

  2. It has no root hairs.

  3. It has no connection with xylem tissue.

  4. Its cells are dead.

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Correct Option: B
Explanation:

Root hairs are unicellular extensions of root epidermis or epiblema. They increase the surface area for absorption and are involved with absorption of water. Root cap typically lacks root hairs and hence not involved in absorption process.

Water and minerals travels upwards through _________

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

  1. Xylem

  2. Pholem

  3. Both A and B

  4. None of these

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Correct Option: A
Explanation:

Water and salts travel upwards mainly in the xylem and food substance travel up and down in the phloem.

Many transplanted seeding may not survive because

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

  1. They do not like the new soil.

  2. They do not get required mineral salt.

  3. Most of the root hairs are lost during transplantation.

  4. The leaves get damaged.

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Correct Option: C
Explanation:

Root hairs are important for absorption of water and minerals. If root hairs are damaged during transplantation absorption of water and minerals will suffer. Hence, transplanted seedling may not survive.

Maximum absorption of water by a root occur in the region of

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

  1. Cell division

  2. Cell elongation

  3. Cell maturation

  4. Cell division and root cap together

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Correct Option: C
Explanation:

In a typical dicot root; root hairs are present in the zone of cell maturation. Root hairs are unicellular extensions of root epidermis, called as epiblema, which absorb water due to increased surface area for absorption. Zone of cell division, zone of elongation and root cap generally lack root hairs.

When the concentration of the soil solutes is low, the 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. Retarted

  2. Increase

  3. Remains normal

  4. Stopped

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Correct Option: B
Explanation:

When concentration of soil solutes is low then the soil solution is hypotonic as compared to cell sap. Water always flows from a hypotonic solution to a hypertonic solution. Hence, when the soil solution is hypotonic due to low concentration of solutes, the water flows into the cell due to the process of endosmosis and absorption of water is increased.