Tag: absorption by roots - the processes involved

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Questions Related to absorption by roots - the processes involved

Multiple choice biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

Root pressure can be demonstrated by means of 

  1. Wilting

  2. Guttation

  3. Transpiration

  4. Exudation/bleeding
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Root exudates function in below ground plant defence. Plant roots are constantly exposed to a variety of natural enemies, including pathogenic microorganisms and root-feeding arthropods. These organisms inhabit the soil surrounding the root system, which is designated the rhizosphere. 

Chemicals secreted into the soil by roots are referred to as root exudates. By doing this root changes the chemical and physical property of soil and inhibit the growth of other plant species. Root pressure can be demonstrated by means of exudation or bleeding caused due to root pathogens.

so the correct answer is 'Exudation'.

Multiple choice biology absorption by roots - the processes involved root pressure transportation in plants factors affecting the transport of water and minerals in plants

Choose the correct answers from the alternatives given.
Root pressure can be measured by

  1. Osmometer

  2. Potometer

  3. Manometer

  4. Porometer
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Different processes can be measured by various apparatus.

A. Osmometer is used to measure osmotic pressure (pressure needed to stop the solvent to pass through the semi-permeable membrane).
B. Potometer is used to measure transpiration rate (the rate at which transpiration occurs).
C. Manometer is used to measure the root pressure (pressure that is exerted by roots such that it allows sap to rise through the plant stem to the leaves).
D. Porometer is used to measure stomatal conductance in leaves.
Hence, the correct answer is 'Manometer'.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

A root hair cell under ordinary conditions have a water potential in the range of?

  1. $-1$ to $-4$ atm.
  2. $-1$ to $+4$ atm.
  3. $1$ to $2$ atm.
  4. $-1$ to $2$ atm.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Under ordinary conditions, the water potential of a root hair cell is negative, typically ranging between -1 and -4 atm, which allows it to absorb water from the soil.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Which of the following is an important feature of roots which help them to absorb water and minerals from the soil?

  1. Roots provide very less surface area

  2. Cells of root contain cell sap

  3. Root hairs have thick walls

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

Larger surface area and thinner walls of root hair are required to absorb water efficiently. 

Cells of the root contain sap which has an accumulation of ions which significantly reduces the water potential. Hence water enters the cells from the soil passively. 
So the correct answer is ' Cells of root contain cell sap'. 

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

The cells of the roots contain cell sap at a .................. concentration than that of surrounding soil water.

  1. Higher

  2. Lower

  3. Equal

  4. All of the following
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cells of the roots contain cell sap (solution) at a higher concentration than that of surrounding soil water. As a result, the water is absorbed by the root hairs. This is because the water always travels from a region of high water potential to the region of lower water potential. Here, the soil possesses a higher water potential as compared to the root hair.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Mineral absorption occurs.

  1. If soil solution is hypotonic

  2. If soil solution is hypertonic

  3. Independent of water potential

  4. Independent of water absorption
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mineral absorption is an active process that requires energy (ATP) and occurs independently of water absorption, which is primarily a passive process driven by water potential gradients.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Rupture and fractionation of water column present in tracheary elements does not occur during ascent of sap due to

  1. Transpiration pull

  2. Weak gravitational pull

  3. Cohesion and adhesion

  4. Lignified thick walls
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transpiratioal or gravitational pull exert strain so they are factors that can cause rupture of the column. 

Lignified walls are only present for structural support.
Cohesion ( attraction of water molecules towards each other) and adhesion (attraction of water molecules and the walls of the tube ) is the reason why  the column doesn't break as these attractive forces overcome the strain developed by Transpiration pull. 
So the correct answer is 'Cohesion and adhesion'.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

In root hair, water enters due to.

  1. Diffusion

  2. WP

  3. T.P.

  4. O.P.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Water enters root hairs from the soil primarily due to osmosis, which is driven by the difference in Osmotic Pressure (O.P.) between the root cell sap and the soil water. Root hairs have a higher solute concentration, resulting in a higher osmotic pressure that pulls water inward.

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

If a cell A with OP $10$ bars and TP $4$ bars is connected to cells B, A and D having OP and TP respectively $4$ and $4$, $10$ and $5$ and $7$ and $3$ bars, the flow of water will be.

  1. C to A, B and D

  2. B to A, C and D

  3. D to A, B and C

  4. A to B, C and D
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Water flows from a region of higher water potential (or lower diffusion pressure deficit / lower osmotic pressure relative to turgor) to a region of lower water potential. Alternatively, using DPD = OP - TP, for cell A: DPD = 10 - 4 = 6. For cell B: OP=4, TP=4, DPD = 0. Since water moves from lower DPD to higher DPD, water flows from cell B (DPD 0) to cell A (DPD 6).

Multiple choice biology absorption by roots - the processes involved manure manures and fertilisers water absorption organ

Which of the following elements are most readily mobilised?

  1. Phosphorus, sulphur, nitrogen and potassium

  2. Calcium, sulphur, nitrogen and phosphorus

  3. Phosphorus, sulphur, nitrogen and calcium

  4. Potassium, sulphur, nitrogen and calcium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Phosphorus, sulphur, nitrogen and potassium most readily mobilise while calcium is structural component which is not remobilised.