Key area 2.5 - Transport systems - plants

Question 1

Name the three transport organs in a plant

Answer 1

Leaves

Stem

Roots

Question 2

Name the leaf structures and their functions

Answer 2

Epidermis - Protective outer layer

Xylem - Transports water

Phloem - Transports Glucose

Palisade Mesophyll - Contains lots of chloroplasts for photosynthesis

Spongy Mesophyll - Loosely arranged for gas exchange

Moist air space - Moist to allow gases to dissolve ( better diffusion )

Stoma / Stomata - Allows carbon dioxide into leaf and oxygen out of leaf

Guard cells - Open and close stoma

Question 3

Describe xylems functions and structural features

Answer 3

Function

Transports water to the leaves for photosynthesis

Structural features

It’s dead tissue
The lignin rings help keep the xylem tissue open

Question 4

Describe phloems structure and functions

Answer 4

Functions

Cells that transport sugars made in leaves up and down the stem to growing and storage tissues

Structure

Sieve plates
Companion cell
Sieve tube
The tissue is alive carries sugar and organic molecules around the plant

Question 5

Describe transpiration

Answer 5

It’s the evaporation of water into the atmosphere from leaves of plants

Water moves from roots to leaves

Root hair cells increase the surface area for the absorption of water from the surrounding soil

Water moves into root hair cells by osmosis

Water then moves up the stem into the leaves through the xylem

And exits through the stomata

Question 6

What 4 factors affect transpiration ?

Answer 6

Temperature

Humidity

Wind speed

Surface area

Rate can be increased by:

Increase in everything but a decrease in humidity

Rate can be decreased by :

Decrease in everything but increase in humidity