5. Support and Transport systems in plants

Question 1

Name the 2 types of seed plants

Answer 1

Gymnosperms and Angiosperms

Question 2

What is an Gymnosperm?

Answer 2

Non-flowering plant with naked seeds on cones.

Question 3

Give 2 examples of Gymnosperms.

Answer 3

cycads, pine trees

Question 4

What is a Angiosperm?

Answer 4

Flowering plant with seeds in fruit.

Question 5

Give 2 examples of Angiosperms.

Answer 5

Sunflowers, fruit trees

Question 6

What are the 2 classes of Angiosperms?

Answer 6

Monocotyledon and Dicotyledon

Question 7

What are the 3 support tissues in plants?

Answer 7

Collenchyma, Sclerenchyma and Xylem

Question 8

What are the 2 transport tissues in plants?

Answer 8

Xylem and Phloem

Question 9

Provide the defintion of Transpiration

Answer 9

Loss of water in the form of water vapour from the aerial parts of a plant.

Question 10

Name the 2 types of Transpiration.

Answer 10

Stomatal and Cuticular

Question 11

Describe the relationship between the structure of a leaf and water loss.

Answer 11

• Thorns and hairs to limit transpiration.
• Smaller leaves means less surface area for evaporation.
• Leaves with sunken stomata will limit transpiration.

Question 12

What do the Guard cells do?

Answer 12

Control rate of transpiration by closing and opening the stomata.

Question 13

What do the Cuticles do?

Answer 13

Waxy layer to reduce cuticular transpiration.

Question 14

Explain Stomatal mechanism during the day.

Answer 14

• Photosynthesis in guard cells of stomata.
• Glucose collects in guard cells.
• Water into guard cells from surrounding epidermis cells thorugh osmosis.
• Guard cells bend outwards because of thin outer wall and thicker inner wall.
• Stomatal pore opens
• Water diffuses out of leaf

Question 15

Explain Stomatal mechanism during the night.

Answer 15

• No photosynthesis
• Reserve glucose used up.
• Water moves into epidermal cells through osmosis.
• Guard cells bend inwards.
• Stomatal pore closes
• Less water diffuses out of leaf.

Question 16

Name the 4 external factors affecting the rate of transpiration.

Answer 16

• High temp increases rate
• Higher light intensity increases rate
• High humidity decreases rate
• Wind decreases rate

Question 17

Name the instrument used to measure the rate of transpiration.

Answer 17

Potometer

Question 18

Explain the uptake of water and minerals by the roots

Answer 18

• Water potential in soil is higher than of cell sap in vacoules of root hair.
• Water molecules move by osmosis through permeable cell wall, selectively permeable cell membrane and cytoplasm through selectively permeable tonoplast into vacoule of root hair.
  -Vacuole swells and pressure in root hair increases.
• Turgor pressure

Question 19

Explain the movement of water from root hair to xylem of root.

Answer 19

• Water potential in root hair is higher than in adjacent parenchyma cells in cortex of root.
• Water moves to xylem of root from cell to cell by osmosis and through cell walls and intercellular air spaces between cells by diffusion.
• Water can’t pass endodermis cell walls
• Water moves through cells of endodermis through pericycle to root xylem.

Question 20

Name the 3 forces responsible for the upward movement of water.

Answer 20

• Transpirational pull
• Root pressure
• Capillarity

Question 21

What is Transpirational pull?

Answer 21

Water lost through leaves by transpiration is replaced by absorbed water from soil through root hairs.

Question 22

What is Root pressure?

Answer 22

Pressure that develops as a result of the absorption of water into root by osmosis.

Question 23

What is Capillarity?

Answer 23

Ability of water molecules to rise up a very narrow tube.

Question 24

Name the 2 forces in Capillarity.

Answer 24

Adhesion and Cohesion

Question 25

What is Adhesion force?

Answer 25

Forces of attraction between water molecules and molecules of the xylem.

Question 26

What is Cohesion force?

Answer 26

Attraction forces between water molecules.

Question 27

Explain the translocation of manufactured food from leaves to other parts of the plant.

Answer 27

• Translocated inside sieve tubes inside of phloem.
• Companion cells assist in functioning of sieve tubes.

Question 28

Provide the definition of Root hair.

Answer 28

Unicellular epidermal outgrowths that increase absorption of root.

Question 29

Provide the definition of Casparian Strips.

Answer 29

Waxy strips in lateral walls of endodermis.