Plants

Question 1

State the features of cell walls.

Answer 1

• Microfibrils of cellulose
• Middle lamella between adjacent cell walls

Question 2

State the features of pallisade cells.

Answer 2

• Long thin cells
• Large vacuole
• Many chloroplasts

Question 3

State the features of a chloroplast.

Answer 3

• Highly selective double plasma membrane
• Thylakoids (arranged in to stacks called grana)
• Stroma

Question 4

State the features of a xylem vessel.

Answer 4

• Continuous tubes
• Thick walls stiffened with lignin

Question 5

State the features of a root hair cell.

Answer 5

• Low water potential
• Carrier proteins for active transport
• Thin - short diffusion pathway
• Large surface area

Question 6

Give four factors affecting transpiration.

Answer 6

1. Light intensity
2. Temperature
3. Humidity
4. Air movement

Question 7

Define: xerophytes

Answer 7

Plants that have developed a range of adaptations to limit water lost via transpiration.

Question 8

Give examples of adaptations to reduce water lost via transpiration.

Answer 8

1. Stomata surrounded by hairs
2. Stomata in sunken pits
3. Thick waxy cuticle
4. Curled leaves
5. Spines
6. Fewer stomata

Question 9

What can be used to measure water uptake?

Answer 9

Potometer

Question 10

What are the precautions when setting up a potometer to ensure reliable results?

Answer 10

• Cut shoot underwater
• Insert apparatus underwater
• Dry off leaves
• Seal joints
• Note where the air bubble starts

Question 11

Why isn’t rate of water uptake equal to rate of transpiration?

Answer 11

1. Water produced in respiration
2. Water used in photosynthesis
3. Water used for turgidity (support)

Question 12

What are the layers of a leaf?

(top to bottom)

Answer 12

• Wax cuticle
• Upper epidermis
• Pallisade mesophyll
• Spongy mesophyll
• Lower epidermis
• Wax cuticle