Absorption in Roots

Question 1

Need for water and minerals for plants

Answer 1

1. Photosynthesis: water is used up in the green leaves as a raw material in the synthesis of glucose.
2. Transpiration: a large quantity of water gets evaporated as water vapour during transpiration for cooling in hot weather, for producing a suction force, etc.
3. Transportation: Transportation of substances in water solution from the roots upward into the shoot or from the leaves to other plants
4. Mechanical stiffness: Water provides turgidity, which is necessary for the stiffness of plant tissues.

Question 2

Use of minerals in plants

Answer 2

Minerals are required as constituents of cell and cell organelles as well as in the synthesis of a variety of compounds or enzymes within the cell.

Question 3

Functions of roots

Answer 3

1. Fixing of plant in the soil giving it support
2. Absorption of water and mineral nutrients from the soil
3. Conduction of water and mineral nutrients into the stem for supply to leaves, flowers, fruits, etc.

Question 4

Imbibition

Answer 4

Imbibition is a phenomenon by which the living or dead 𝗽𝗹𝗮𝗻𝘁 𝗰𝗲𝗹𝗹𝘀 absorb 𝘄𝗮𝘁𝗲𝗿 𝗺𝗼𝗹𝗲𝗰𝘂𝗹𝗲𝘀 by 𝘀𝘂𝗿𝗳𝗮𝗰𝗲 𝗮𝘁𝘁𝗿𝗮𝗰𝘁𝗶𝗼𝗻

Question 5

Diffusion

Answer 5

Diffusion is the 𝗳𝗿𝗲𝗲 𝗺𝗼𝘃𝗲𝗺𝗲𝗻𝘁 of molecules of a substance from the region of their 𝗵𝗶𝗴𝗵𝗲𝗿 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 to a region of their 𝗹𝗼𝘄𝗲𝗿 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 when the two are in 𝗱𝗶𝗿𝗲𝗰𝘁 𝗰𝗼𝗻𝘁𝗮𝗰𝘁

Question 6

Osmosis

Answer 6

Osmosis is the movement of 𝘄𝗮𝘁𝗲𝗿 𝗺𝗼𝗹𝗲𝗰𝘂𝗹𝗲𝘀 from a 𝗵𝘆𝗽𝗼𝘁𝗼𝗻𝗶𝗰 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻 to a 𝗵𝘆𝗽𝗲𝗿𝘁𝗼𝗻𝗶𝗰 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻 through a 𝘀𝗲𝗺𝗶 𝗽𝗲𝗿𝗺𝗲𝗮𝗯𝗹𝗲 𝗺𝗲𝗺𝗯𝗿𝗮𝗻𝗲

Question 7

Endosmosis

Answer 7

𝗜𝗻𝘄𝗮𝗿𝗱 diffusion of 𝘄𝗮𝘁𝗲𝗿 through a 𝘀𝗲𝗺𝗶-𝗽𝗲𝗿𝗺𝗲𝗮𝗯𝗹𝗲 membrane when the surrounding solution is 𝗹𝗲𝘀𝘀 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗲𝗱

Question 8

Exosmosis

Answer 8

𝗢𝘂𝘁𝘄𝗮𝗿𝗱 diffusion of 𝘄𝗮𝘁𝗲𝗿 through a 𝘀𝗲𝗺𝗶-𝗽𝗲𝗿𝗺𝗲𝗮𝗯𝗹𝗲 membrane when the surrounding solution is 𝗺𝗼𝗿𝗲 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗲𝗱.

Question 9

Semi-permeable membrane

Answer 9

A membrane which allows the passage of molecules 𝘀𝗲𝗹𝗲𝗰𝘁𝗶𝘃𝗲𝗹𝘆.

Question 10

Tonicity

Answer 10

𝗥𝗲𝗹𝗮𝘁𝗶𝘃𝗲 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 of the solutions that determine the 𝗱𝗶𝗿𝗲𝗰𝘁𝗶𝗼𝗻 and 𝗲𝘅𝘁𝗲𝗻𝘁 of diffusion is known as tonicity.

Question 11

Isotonic

Answer 11

A condition in which the 𝗿𝗲𝗹𝗮𝘁𝗶𝘃𝗲 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 of 𝘄𝗮𝘁𝗲𝗿 𝗺𝗼𝗹𝗲𝗰𝘂𝗹𝗲𝘀 and that of the 𝘀𝗼𝗹𝘂𝘁𝗲 on either side of the cell membrane is the same.

Question 12

Hypertonic solution

Answer 12

A condition in which the solution outside the cell has a 𝗵𝗶𝗴𝗵𝗲𝗿 𝘀𝗼𝗹𝘂𝘁𝗲 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 than the fluids inside the cell.

Question 13

Hypotonic solution

Answer 13

A condition in which the solution outside the cell has a lower solute concentration than the fluids inside the cell.

Question 14

Hypertonicity

Answer 14

A condition in which the solution outside the cell has a 𝗵𝗶𝗴𝗵𝗲𝗿 𝘀𝗼𝗹𝘂𝘁𝗲 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 than the fluids inside the cell.

Question 15

Active transport

Answer 15

The passage of a substance (salt or ion) from its 𝗹𝗼𝘄𝗲𝗿 𝘁𝗼 𝗵𝗶𝗴𝗵𝗲𝗿 𝗰𝗼𝗻𝗰𝗲𝗻𝘁𝗿𝗮𝘁𝗶𝗼𝗻 through a 𝗹𝗶𝘃𝗶𝗻𝗴 𝗰𝗲𝗹𝗹 𝗺𝗲𝗺𝗯𝗿𝗮𝗻𝗲 𝘂𝘀𝗶𝗻𝗴 𝗲𝗻𝗲𝗿𝗴𝘆 from the cell

Question 16

Turgidity

Answer 16

State of a cell in which the 𝗰𝗲𝗹𝗹 𝘄𝗮𝗹𝗹 𝗶𝘀 𝗿𝗶𝗴𝗶𝗱

and 𝘀𝘁𝗿𝗲𝘁𝗰𝗵𝗲𝗱 by an 𝗶𝗻𝗰𝗿𝗲𝗮𝘀𝗲 𝗶𝗻 𝘁𝗵𝗲 𝘃𝗼𝗹𝘂𝗺𝗲 𝗼𝗳 𝘃𝗮𝗰𝘂𝗼𝗹𝗲𝘀 due to 𝗮𝗯𝘀𝗼𝗿𝗽𝘁𝗶𝗼𝗻 𝗼𝗳 𝘄𝗮𝘁𝗲𝗿.

Question 17

Plasmolysis

Answer 17

𝗖𝗼𝗻𝘁𝗿𝗮𝗰𝘁𝗶𝗼𝗻 𝗼𝗳 𝗰𝘆𝘁𝗼𝗽𝗹𝗮𝘀𝗺 from the cell wall caused due to 𝘄𝗶𝘁𝗵𝗱𝗿𝗮𝘄𝗮𝗹 𝗼𝗳 𝘄𝗮𝘁𝗲𝗿 when placed in a 𝗵𝘆𝗽𝗲𝗿𝘁𝗼𝗻𝗶𝗰 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻.

Question 18

Flaccidity

Answer 18

Condition in which the cell content is 𝘀𝗵𝗿𝘂𝗻𝗸𝗲𝗻 and the cell is no more “tight”.

Question 19

Uses of turgidity in plants

Answer 19

1. Turgidity provides rigidity to soft tissues such as the leaves.
2. Turgor pressure helps push through the hard ground.
3. Turgor in root cells builds up root pressure.
4. Turgor is used in the opening and closing of the stomata.
5. Turgor movement

Question 20

Guttation

Answer 20

Guttation is the 𝗹𝗼𝘀𝘀 𝗼𝗳 𝗲𝘅𝗰𝗲𝘀𝘀𝗶𝘃𝗲 𝘄𝗮𝘁𝗲𝗿

through 𝘁𝗶𝗻𝘆 𝘄𝗮𝘁𝗲𝗿 𝗱𝗿𝗼𝗽𝗹𝗲𝘁𝘀 along the margin of leaves caused by 𝗲𝘅𝗰𝗲𝘀𝘀 𝗿𝗼𝗼𝘁 𝗽𝗿𝗲𝘀𝘀𝘂𝗿𝗲.

Question 21

Water available to the plants for absorption by roots is

Answer 21

Hygroscopic water

Question 22

Examples of turgor movements in plants

Answer 22

1. Mimosa pudica

2. Insectivorous plants whose leaves close up to entrap a living prey

Question 23

Osmotic pressure

Answer 23

Measure of a solution’s tendency to take in water by osmosis.

Question 24

Root pressure

Answer 24

Pressure developed in the roots due to continued inward movement of water through cell-to-cell osmosis which helps in the ascent of cell sap upwards through the stem.