Plant Systems

Question 1

What are the main tissues found in a plant’s vascular system?

Answer 1

Xylem and Phloem

Question 2

What is the primary function of the xylem?

Answer 2

To transport water and other minerals and nutrients for growth and other processes.

Question 3

Where does gas exchange occur in plants?

Answer 3

Stomata (Stoma for singular)

Question 4

What is the primary function of the phloem?

Answer 4

Transports sugars in the form of sucrose, and the products for photosynthesis

Question 5

What is the function of guard cells in plants?

Answer 5

Control the entry and exit of gases for gas exchange

Question 6

How do guard cells open?

Answer 6

Potassium ions are pumped into guard cells via active transport, this draws water into the guard cell do to the higher solute concentration, which causes the guard cell to swell become turgid, which causes the cell to curve and open.

Question 7

How do guard cells close?

Answer 7

Potassium ions are pumped out of the cell and water is drawn out this causes the cell to become flaccid and close.

Question 8

What is the difference between xylem and phloem tissue

Answer 8

Xylem
- transports water and minerals
- from roots to leaves and unidirectional
- Source = absorbed via osmosis from the root hairs in the soil
Phloem
- transports sucrose and products if photosynthesis
- From leaves or roots to where they are needed and both directions
- Source = photosynthetic cells or storage tissue

Question 9

What is transpiration?

Answer 9

Transpiration is the loss of water vapour by evaporation (energy from the sun) from the leaves, especially from the stomata.

Question 10

What environmental factors can increase the rate of transpiration?

Answer 10

Light intensity, temperature, wind speed, and low humidity.

Question 11

What is root pressure?

Answer 11

A force that pushes water up the stem from the roots.

Question 12

Adhesion

Answer 12

The force of attraction between water molecules and the molecules that make up the outside of a container

Question 12

What is capillary action?

Answer 12

Further to root pressure these forces allow water to move against gravity from root to stem.The combination of these is called capillary action.

Question 13

Cohesion

Answer 13

Force of attraction between water molecules so if one molecule is moving upwards others will cohere to it.

Question 14

What is translocation in plants?

Answer 14

Transports the products of photosynthesis and some minerals from the site of photosynthesis to the stems and roots to be used or to the roots to be stored, via the phloem.

Question 15

What is a “source” and a “sink” in the context of plant translocation?

Answer 15

A source is a part of the plant that produces or releases sugars (e.g., leaves), while a sink is a part that consumes or stores sugars (e.g., roots, fruits).

Question 16

What is the function of root hair cells in plants?

Answer 16

increase the surface area for absorption of water and nutrients.

Question 17

How is waste removed from plants?

Answer 17

Waste can be transported via the phloem to be removed in different ways. E.g Mangroves have sacrificial leaves that tore excess salt and fall off.