Lecture 27. Circulation and Gas Exchange in Plants

Question 1

How do animals prevent rupturing ?

Answer 1

They have semi permeable membranes and continually excrete soluble ions

Question 2

What type of cell wall do plant cells possess ?

Answer 2

A relatively inelastic cell wall

Question 3

What does high pressure exerted on the cell wall inhibit ?

Answer 3

The movement of water into the cell

Question 4

What is turgor pressure ?

Answer 4

Hydrostatic pressure developed within the plant cell

Question 5

What is the pressure in plant cell ?

Answer 5

1-2 mega pascals

Question 6

What can japanese knotweed do ?

Answer 6

Grow through concrete

Question 7

How does japanes knotweed work ?

Answer 7

Creates a huge rhizone network

Question 8

What are the transport pathways ?

Answer 8

1. Symplast
2. Apoplast
3. Gas filled intercellular spaces

Question 9

What is a symplast ?

Answer 9

Interconnecting cytoplasm via plasmodesmata

Question 10

What is an apoplast ?

Answer 10

Interconnecting cell walls

Question 11

What type of pathway is apoplast ?

Answer 11

Low resistance pathway

Question 12

What type of pathway is symplast ?

Answer 12

A high resistance pathway

Question 13

What is a typical transpiration rate ?

Answer 13

4mm per second

Question 14

What is movement of water molecules in response to /

Answer 14

Gradient in free energy

Question 15

What is the chemical potential of water equal to ?

Answer 15

The chemical potential of water in an arbitrary reference state

Question 16

What can effect chemical potential of water

Answer 16

1. Concentration
2. Pressure
3. Electrochemical gradient
4. Gravity

Question 17

What is chemical potential of water ?

Answer 17

The amount of free energy in water in a given system

Question 18

What is the equation of water potential ?

Question 19

What is the water potential of pure water ?

Answer 19

Zero

Question 20

What are xylem vulnerable to ?

Answer 20

Cavitation