Transport (plants)

Question 1

what do phloem do?

Answer 1

TRANSPORT FOOD:

1. transports sugars and amino acids from where they’re made in the leaves to other parts of the plant
2. called TRANSLOCATION

Question 2

what do xylem do?

Answer 2

TRANSPORT WATER AND MINERALS:

- carry water and mineral salts from the roots up the shoot to the leaves in the TRANSPIRATION stream.

Question 3

how is water and mineral ions absorbed by root hair cells?

Answer 3

• root hair cells grow long ‘hairs’ which stick out into the soil.
• each branch of a root will be covered in millions of these microscopic hairs
• this gives the plant a big SA for absorbing water (osmosis) and minerals ions (active transport) from the soil.

Question 4

what is transpiration?

Answer 4

the evaporation of water from the surface of a plant.

side effect of adaption for photosynthesis- having stomata open for gas exchange means water can diffuse out

Question 5

how is rate of transpiration affected by LIGHT INTENSITY?

Answer 5

• the BRIGHTER the light, the GREATER the transpiration rate.
• stomata begin to close as it gets darker.
• Photosynthesis can’t happen in the dark, so they don’t need to be open to let CO2 in.
• when stomata are closed, very little water can escape.

Question 6

how is rate of transpiration affected by TEMPERATURE?

Answer 6

the WARMER it is, the FASTER transpiration happens.

when it’s warm the water particles have more energy to evaporate and diffuse out of the stomata.

Question 7

how is rate of transpiration affected by WIND SPEED?

Answer 7

• the HIGHER the wind speed, the GREATER the transpiration rate.
• if it’s windy, water vapour outside the leaf is swept away, maintaining a LOW water concentration gradient outside the leaf.
• diffusion then happens quickly.

Question 8

how is rate of transpiration affected by HUMIDITY?

Answer 8

• the DRIER the air around a leaf, the FASTER transpiration happens.
• if the air is humid = lots of water in it already = no conc. gradient = slow diffusion rate.