9.2 transport in angiospermophytes

Question 1

Define transpiration

Answer 1

The loss of water vapour from the leaves and other aerial parts of the plant

Question 2

Explain how water is carried by the transpiration system

Answer 2

Xylem vessel: dead cells of xylem transport water from root to shoot
Transpiration pull: water from neighbour cell moves in by osmosis and pulls entire column with it, maintains high concentration of water to the leave
Cohesion: water is connected hydrogen bonding which goes against gravity to pull up
Adhesion: water bond to surface of vessel prevents it from sliding down

Question 3

State how plants support themselves

Answer 3

Thickened cellulose: thick cell wall
Cell turgor: pressure of water on cell wall
Lignified xylem:

Question 4

What do you guard cells do?

Answer 4

Guard cells regulate the transpiration but opening and closing the stoma

• gaurd cell curved _open stoma
• guard cell wilted_close stoma

Question 5

What hormone causes the closing of the stoma

Answer 5

Plant hormone abscisic acid causes the closing of the stoma. It is produce a time of drought.

Question 6

Splaine how the antibiotic factors light, temperature, wind and humility affect the rate of transpiration in a typical terrestrial plant

Answer 6

Temperature: increase in temperature causes increase in transpiration because water evaporates faster due to heat

light: increase of like causes increase of transpiration because water evaporates faster to the heat admitted by light .

Humidity: decrease of humidity increase of transpiration because water moves to less humid atmosphere gradient.

Wind: increase of when causes increase of transpiration because when carries away humid air and replaces it with drier air

Question 7

Outline for adaptions of xerophytes that help to reduce transpiration

Answer 7

Small thick leaves - decree surface area for water to be lost.

Reduced number of stoma – decrease the opening which water can be lost.

Stoma located in pits and crypts – pit captures humid air around stoma increases the humidity which decreases the transpiration.

Hair likes cells on leaf: water vapor stick some hair like cells increase his humility which therefore decreases transpiration

Question 8

On the role of phloem an active translocation of sugar and amino acids from source (photosynthesis tissue & storage organs) to sink (fruit seeds and roots)

Answer 8

1. Sugar cells made at source move to sieve tube of phloem (from higher concentration to lower. )
2. Water moves by osmosis into the phloem from xylem making water and sugar =phloem sap. Uptake of water causes positive pressure which causes flow of phloem sap to move to sink .
3. From sink changes to starch and diffuses to other parts of the plant. Pressure is gone. Plant gets nourishment.
4. Xylem recycles water from sink to source
   - loading sugar at source and removing sugar to sink is active transport.

Question 9

Outline how the root system provides our service area for mineral ions in water uptake by means of branching and root hairs

Answer 9

Plants take up water and essential minerals via their roots and thus need a maximal surface area in order to optimise this uptake
The monocotyledon root has a fibrous, highly branching structure which increases surface area for maximal absorption
The dicotyledon root has a main tap root with lateral branches to maximise surface area
The root epidermis may have extensions called root hairs which further increase surface area for mineral and water absorption
-water moves in due to concentration gradient (apoplastic, symplastic, vaculoplastic)
These root hairs have carrier proteins and ion pumps in their plasma membrance, and many mitochondria within the cytoplasm, to aid active transport to absorb ions

Question 10

Explain the process of mineral ions absorption from the soil into the routes by active transport

Answer 10

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