Acquisition Of Water And Minerals

Question 1

What is the need for transport

Answer 1

As land plants evolved, competition for light, water and nutrients increased. Simple ways of transportation became inadequate, leading to evolution of vascular tissues .

Question 2

Methods of water and solute movement

Answer 2

1. Active transport
2. Passive short distance transport
   I. Diffusion
   II. Osmosis
   III. Imbibition
   IV. Facilitated diffusion
3. Passive long distance transport
   I. Bulk flow

Question 3

What is active transport

Answer 3

Movement of some materials across membrane take place using ATP. This process is called active transport.

Question 4

What causes diffusion

Answer 4

Thermal energy in molecules due to their constant motion

Question 5

Define diffusion

Answer 5

In the absence of other forces the movement of molecules of a substance from a place where it is more concentrated to a place where it is less concentrated due to random motion of molecules

Question 6

True or false
Movement of a molecule is random, movement of a population is directional

Answer 6

True

Question 7

What are the features of diffusion

Answer 7

1. Takes place according to a concentration gradient
2. Spontaneously
3. Don’t use metabolic energy

Question 8

Can diffusion take place across the membrane

Answer 8

Yes. If the membrane is permeable to the mooecules

Question 9

What is osmosis

Answer 9

A special type of diffusion of free water molecules across a selectively permeable membrane.

Question 10

What is free water

Answer 10

Water molecules that are not bound to solutes or surfaces

Question 11

What is imbibition ?

Answer 11

The physical absorption of water molecules by hydrophilic materials

Question 12

What is facilitated diffusion?

Answer 12

Movement of water and hydrophilic solutes across the membranes passively with the help of transport proteins that span the membrane.

Question 13

Features of transport proteins

Answer 13

1. Very specific.
2. Movement along concentration gradient
3. Passive movement

Question 14

What is bulk flow

Answer 14

The movement of liquid and materials (entire solution) in response to pressure gradient

Question 15

Bulk flow direction

Answer 15

Always flows from higher pressure to lower pressure region

Question 16

What method of transport is independent of solute concentration

Answer 16

Bulk flow

Question 17

Features of bulk flow

Answer 17

1. Long distance transport
2. Flow does not occur through membranes
3. Greater speed than diffusion
4. Independent of solute concentration gradient

Question 18

What is water potential

Answer 18

The physical property that predicts the direction in which the water will flow governed by solute concentration and applied pressure

Question 19

Direction of water movement

Answer 19

From a regions of higher water potential to a region of lower water potential if there is no barrier to its flow

Question 20

What is the symbol for water potential

Answer 20

ψ

Question 21

What is the unit for ψ

Answer 21

Megapascal
MPa

Question 22

What is the ψ of pure water in a container open to atmosphere under standard condition

Answer 22

0 MPa

Question 23

What is the standard condition

Answer 23

Sea level
Room temperature

Question 24

What is the water potential equation

Answer 24

ψ = ψs + ψp

Question 25

Solute potential is directly proportional to

Answer 25

The molarity of a solution

Question 26

What is another name for ψs

Answer 26

Osmotic potential, since solutes affect the direction of osmosis

Question 27

What are the typical solutes in plants

Answer 27

Mineral ions
Sugars