Transport systems - plants

Question 1

Name the three main plant organs, labelling the key features of a leaf

Answer 1

Waxy Cuticle – Prevents water loss

Upper epidermis – Allows light to pass through and prevents water loss.

Palisade mesophyll - Main cells involved in photosynthesis.

Spongy mesophyll - Contain air spaces to allow gas exchange.

Guard cells - control the opening and closing of stomata.

Stomata - Air spaces that allows oxygen and water to leave and carbon dioxide to enter the leaf.

Question 2

Describe how a plant obtains water

Answer 2

A plant obtains water through the roots.

Roots contain specialised cells called root hair cells.

These cells increase the surface area in which the plant can absorb water and nutrients from the soil.

Question 3

Describe how the plant transports water and minerals

Answer 3

Water is transported from the roots to other parts of the plant through dead Xylem vessels.

These dead xylem vessels(lignified) contains rings of lignin. This allows the xylem vessel to withstand the pressure changes as water moves throughout the plant.

Question 4

Describe the process of transpiration

Answer 4

Transpiration is the movement of water throughout the plant. Water evaporates from the stomata in the leaf, this causes pressure changes within the plant meaning more water is drawn through the plant from the roots back into the leaves.

Question 5

Identify factors that affect transpiration

Answer 5

As transpiration is dependent upon the evaporation of water from the stomata. Any environmental condition that affects this evaporation of water will affect the rate of transpiration.

These factors are:

Wind speed
Humidity
Temperature
Surface area

Question 6

Describe how sugar is transported around the plant

Answer 6

Sugar is transported up and down the plant in living phloem tissue.

Phloem cells have sieve plates and associated companion cells to allow sugar to be transported to all parts of the plant.