Transport And Coordination In Plants Flashcards Preview

GCSE Biology*** > Transport And Coordination In Plants > Flashcards

Flashcards in Transport And Coordination In Plants Deck (37)
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1
Q

What does the transport system in plants enable plant to do ?

A
  • enables leaves to receive water for photosynthesis
  • mineral ions needed to convert the products of photosynthesis into useful substances
  • once these are formed these are transported to other parts of the plant like growing points and storage areas
2
Q

What does xylem do?

A

• transports water and mineral irons from the roots to the leaves

3
Q

What are nitrate ions needed for in a plant ?

A

To make amino acid’s and proteins

4
Q

What are magnesium ions needed for in a plant ?

A

To make chlorophyll

5
Q

What is xylem made up of ?

A

Thick walled vessels, they are dead cells containing no cytoplasm - they are completely hollow and arranged end to end

6
Q

Which way does water and mineral ions move in xylem ?

A

From ROOTS to SHOOTS

7
Q

What are the walls of xylem thickened with ? And what does this do ?

A

Lignin, which makes them
• waterproof
• very strong - stops cells collapsing inwards
• give stems support

8
Q

What does phloem transport ?

A

It transports sucrose and amino acids from the leaves to the growing points or storage areas

9
Q

What cells do phloem consist of ?

And why ?

A

Living cells, as tubes have cytoplasm in the walls, as cells need to be kept alive to transport the substances

10
Q

How is sucrose and amino acid’s transported ?

A

Active transport

11
Q

What is sugar converted into in the leaves ?

A

Sucrose, as the sugar made in photosynthesis is converted to sucrose for transport through the Phloem to the growing tips

12
Q

What direction do the fluids move in the phloem ?

A

Both directions

13
Q

What are the cell walls made of in the phloem tube ?

A

Cellulose

14
Q

How is water uptaked ?

A

By the roots by the root hair cells

15
Q

How is water absorbed by the root hair cell ?

A
  • plants take in water from the soil through the root hairs
  • The hairs increase the surface area of the roots epidermis
  • The long thin outer projection penetrate between the soil particles reaching the soils water
  • this water has some solutes dissolved in it but the concentration is much lower than the concentration of solutes inside the root hair cell. The soil water has a higher concentration of water molecules and water will enter the cell by osmosis
  • this dilutes the contents of the cell increasing its concentration of water molecules. Water will then move from the root hair cell into the cortex cells of the root
  • this gradient is maintained as water is constantly being taken up by the xylem
16
Q

How are mineral ions uptaken ?

A

By active transport and diffusion

17
Q

What is transpiration?

A

The evaporation of water from the surface of the leaf

18
Q

What is the transpiration stream?

A

Transpiration causes water to be pulled up by the xylem in the stem and roots in a continuous flow known as the transpiration stream

19
Q

Where does the water leave during transportation?

A

Through the stomata

20
Q

Where does the water vapour in transportation evaporate between ?

A

The water leaves the mesophyll and evaporate into that space between spongy Mesophyll

21
Q

What are the four functions of the transpiration stream ?

A
  • to carry mineral ions to the leaves
  • to keep heard your pressure high in the leaf cells, holding the leaves up
  • evaporation cool the leaves
  • transpiration is inevitable as the stomata has to be at least partly open to allow O2 and CO2 to diffuse freely
22
Q

What are the five factors that affect the rate of transpiration?

A
  • temperature
  • humidity
  • wind speed
  • water supply
  • light intensity
23
Q

How does temperature affect the rate of transpiration?

A

• on a hot day, water will evaporate quickly from the leaves of the plant. Therefore transpiration will increase if temperature increases.

24
Q

How does humidity affect the rate of transpiration?

A
  • very humid air contains a great deal of water vapour- therefore it can only except a small amount of water from the leaf, so transpiration slows down
  • in dry at the diffusion of water vapour from the leaf to the atmosphere will be rapid. Transpiration increases if humidity decreases
25
Q

How does windspeed affect the rate of transpiration?

A
  • in still air, the region around the transpiring leave will become saturated with water vapour, so that no more can I escape from the leaf - causing transportation to slow down
  • in moving air, the water vapour will be swept away from the leaf as fast as it diffuses out. This will speed up transpiration
  • transpiration therefore increases as wind speed increases
26
Q

How does light intensity affect the rate of transpiration?

A

• light itself does not affect evaporation, but in daylight the stomata is open to supply carbon dioxide for photosynthesis, this allows more water to diffuse out of the leaves and into the atmosphere

27
Q

How does watersupply affect the rate of diffusion?

A
  • if water is in short supply, and the plant is losing water by transpiration faster than it is being taken up by the roots, then the plant will start to wilt
  • before this happens the stomata starts to close, therefore reducing transpiration and delaying wilting
28
Q

What is a tropism ?

A

The growth of a plant to water directional stimulus

29
Q

What is phototropism ?

A

The growth of a plant towards light

30
Q

What is positive phototropism ?

A

The growth of a plant towards light E.g. Stem

31
Q

What is negative phototropism ?

A

Growth of a plant away from the light e.g. roots

32
Q

What is Geotropism ?

A

Is the growth away from gravity

33
Q

What is positive Geotropism ?

A

The growth with the direction of gravity e.g. Roots

34
Q

What is negative Geotropism ?

A

Is the growing upwards of a plant away from gravity

35
Q

What is translocation ?

A

The movement of sugars around the body

36
Q

Where is auxin produced?

A

In the growing tip

37
Q

How does a plant grow towards the light?

A
  • The growing tip grows towards the light as auxin is produced in the growing tip, light destroys auxin on the sunny side, so auxin diffuses over to the Shady side
  • auxin accumulates on the Shady side this causes increased cell elongation. Therefore the growing tip leans/grows towards the sun