idk what to name this

Question 1

Pathway by which water is transported from the root hairs to the xylem
Hint: A and S

Answer 1

Apoplast: Water moves through plant tissue via interconnected “free space” between cellulose fibres in cell walls→ transportation of water by mass flow

Symplast: Water moves through plant tissue by entering the cell membrane by osmosis and moving through the cytoplasm→ slower flow of water

Question 2

Define the term transpiration and explain that transpiration is a consequence of gaseous exchange in plants

Answer 2

transpiration: process through which water vapour is lost from aerial parts of plants as a result of evaporation of water
- -> occurs at the surface of mesophyll cells into the air spaces within the leaf,
- -> followed by diffusion of water vapour out of the leaf, mainly through the stomata, down a water vapour concentration gradient from the surface of the spongy mesophyll cells via the air spaces in the leaf to the atmosphere

stomata must be open for gaseous exchange - uptake of co2 and release of o2 by diffusion as co2 is needed for photosynthesis while o2 is a by-product from photosynthesis. water vapour diffuses out through the open stomata during transpiration.

Question 3

Effects of variation of air movement on transpiration

Answer 3

Stronger wind–> higher rate of transpiration
The stronger the wind blows the higher the rate of transpiration as the wind carries/blows away saturated air from around the leaves, thereby maintaining a concentration gradient between the leaf interior and the air outside stomata.

Question 4

Effects of temperature on transpiration

Answer 4

High temperature increases the rate of transpiration.
A rise in surrounding temperature will increase the heat energy which in turn increases the evaporation of water from the surface of mesophyll cells

Question 5

Effects of humidity on transpiration

Answer 5

Low humidity increases the rate of transpiration.
Humidity: Low humidity will increase the water vapour concentration gradient between the leaf and atmosphere, hence increases water evaporation.

Question 6

Effects of water supply on transpiration

Answer 6

High water supply increases the rate of transpiration.

Water supply: Ample water supply will keep the leaf cells turgid and stomata remain open.

Question 7

Effects of light intensity on transpiration

Answer 7

High light intensity increases the rate of transpiration.

Light intensity: In sunlight, the stomata become open and become wider

Question 8

How wilting occurs

Answer 8

Under strong sunlight, when the rate of transpiration exceeds the rate of absorption of water by roots, the cells lose their turgor and become flaccid and the plant wilts

Question 9

translocation

Answer 9

the transport of food in the phloem tissue

Question 10

how water is transported from roots to leaves (R andT)

Answer 10

root pressure: active transport of ions into root xylem vessel lowers its water potential resulting in an accumulation of water in roots by osmosis and flows upwards to a few meters but is insufficient up to the leaves
transpiration: regulated by guard cells surrounding the stomata, water can move up the xylem sap to the top of the tallest tree, cohesion-adhesion theory