Plants

Question 1

What are some plant tissues?

Answer 1

Plant tissues include:
- epidermal tissues (upper and lower)
- palisade mesophyll
- spongy mesophyll
- xylem and phloem

Question 2

What are these chemical symbols?
CO2, H2O, O2 and C6H12O6 .

Answer 2

Carbon Dioxide
Water
Oxygen
Glucose

Question 3

What is the word equation for photosynthesis?

Answer 3

carbon dioxide + water → glucose + oxygen (CWOG)

Question 4

What is the balanced symbol equation for photosynthesis?

Answer 4

6CO2 + 6H2O –> 6O2 + C6H12O6

Question 5

What is the glucose produced in photosynthesis used for?

Answer 5

The glucose produced in photosynthesis may be:
- used for respiration
- converted into insoluble starch for storage
- used to produce fat or oil for storage
- used to produce cellulose, which strengthens the cell wall
- used to produce amino acids for protein synthesis. (To produce proteins, plants also use nitrate ions that are absorbed from the soil.)

Question 6

What factors affect the rate of transpiration?

Answer 6

• Wind (air flow)
• Light intensity
• Temperature
• Humidity

Question 7

Why does the air flow affect the rate of transpiration?

Answer 7

Increased air flow increases the rate of transpirtation.
It increases transpiration as it carries water away from the plant’s leaves, which encourages more water to evaportate.

Question 8

Why does the light intensity affect the rate of transpiration?

Answer 8

Increased light intensity makes water evaportate faster, which increases the rate of transpiration.

Question 9

Why does the temperature affect the rate of transpiration?

Answer 9

Increased temperature makes water evaportate faster, which increases the rate of transpiration.

Question 10

Why does the humidity affect the rate of transpiration?

Answer 10

Increasing humidity decreases the rate of transpiration.
Increases humidity increases the amount of water in the air. This makes it more difficult for water to evaportate.

Question 11

For measuring the rate of transpiration, what equipment do you use?

Answer 11

a potometer

Question 12

When measuring the rate of transpiration with a potometer, why is the calculation only an estimate?

Answer 12

A small amount of the water taken up by the shoot is used in the leaves and is not transpired.

Question 13

What is the structure of xylem cells?

Answer 13

• no end walls (form a long tube for ease of transport)
• dead (the tubes are hollow and the resistance to water flow is low)
• Lignin (lignin in the cell walls strengthens and waterproofs the elongated cells)

Question 14

What are the root hair cells adaptions?

Answer 14

Root hairs (long projections stick out from the cell and into the soil to increase the surface area over which water and minterals can be absorbed.)
Mitochondria (lots of mitochondria ensure there is enough energy for active transport minerals up the stem)

Question 15

How do guard cells close the stomata?

Answer 15

To close the stomata, the guard cells lose water and return to a limp state.

Question 16

How do guard cells open the stomata?

Answer 16

The guard cells can open the stomata by taking up lots of water, causing them to swell.

Question 17

What do stomata do at night?

Answer 17

• At night, stomata close because, in the absence of sunlight, carbon dioxide is not required for photosynthesis.
• At this time, their only objective is to prevent water loss.

Question 18

Explain why translocation is important to plants.

Answer 18

Translocation is important because some parts of the plant don’t have easy access to energy from respiration. The energy is provided to them through the sugars in cell sap, which is transported in translocation.

Question 19

What is the process by which food produced in photosynthesis is transported from the leaves to the growing regions of plants and storage organs?

Answer 19

Translocation