Plant Structure & Function Qs

Question 1

What is photosynthesis?

Answer 1

When PLANTS use LIGHT ENERGY to produce GLUCOSE and OXYGEN from CO2 and WATER reacting in the CHLOROPLAST

Question 2

Write the word equation for photosynthesis

Answer 2

Carbon Dioxide + Water —> Glucose + Oxygen

Question 3

Write the symbol equation for photosynthesis

Answer 3

CO2 + H2O → C6H12O6 + O2

Question 4

What type of reaction is photosynthesis?

Answer 4

Endothermic (takes in light energy)

Question 5

What factors affect the rate of photosynthesis?

Answer 5

Temperature; light intensity; carbon dioxide concentration

Question 6

What is glucose used for?

Answer 6

Respiration, to make protein, to convert into starch and be stored

Question 7

Why do plants only store glucose in the form of starch?

Answer 7

• Starch is large and insoluble
• Can be stored
• Will not diffuse out of chloroplast

Question 8

Explain how light intensity affects the rate of photosynthesis

Answer 8

• Higher light intensity
• Higher/faster rate of photosynthesis
• Light energy is needed/used in photosynthesis

Question 9

Explain how CO2 concentration affects the rate of photosynthesis

Answer 9

• Carbon dioxide is a reactant

- It is needed/used in photosynthesis

Question 10

Explain how temperature affects the rate of photosynthesis

Answer 10

• Increase in temperature = more kinetic energy
• Enzyme and substrate collide more = more enzyme substrate complexes
• Decrease on graph = enzyme/active site denatures
• Active site changes shape
• No enzyme substrate complexes form

Question 11

Describe light intensity as a limiting factor

Answer 11

• Light intensity is a limiting factor
• As LI increases, rate of photosynthesis increases
• To a certain point
• Beyond, the rate of P. slows down
• Temp. and conc. of CO2 are limiting factors

Question 12

Describe concentration of CO2 as a limiting factor

Answer 12

• Conc. of CO2 is a limiting factor
• As C increases, rate of photosynthesis increases
• To a certain point
• Beyond, the rate of P. slows down
• Temp. and LI are limiting factors

Question 13

Describe temperature as a limiting factor

Answer 13

• As temp. increases, rate of P increases
• Up to a certain point
• Beyond, rate of P decreases and stops

Question 14

Describe how water enters the root hair cells

Answer 14

• High conc. = soil
• Low conc. = root hair cell
• Water moves from soil to cell via osmosis

Question 15

Describe the structure of a leaf

Answer 15

Waxy Cuticle
Epidermal Cells
Palisade Cells
Spongy Mesophyll Layer
Xylem and Phloem Tubes
Guard Cells
Stomata

Question 16

How do mineral ions enter root hair cells?

Answer 16

• Area of high conc. = root hair cell
• Area of low conc. = soil
• Mineral ions move from soil to cell
• via active transport (energy needed)

Question 17

What are adaptations of root hair cells?

Answer 17

• Are many of them and long = more water and mineral ions absorbed
• Thin walls = large surface area + short diffusion distance
• Mitochondria= provides energy (active transport)

Question 18

What conditions speed up the rate of transpiration?

Answer 18

• Hot day
• Dry day
• Windy day
• Sunny day

Question 18

What conditions slows down the rate of transpiration?

Answer 18

• Cold day
• Humid day
• Still day
• Dull day

Question 19

What is translocation?

Answer 19

• Movement of sugar
• In the form of sucrose
• Through the phloem tube
• In both directions
• Phloem tube has sieve plates

Question 20

Describe the function of the stomata?

Answer 20

• Gas exchange

- Allows water vapour to leave/evaporate (via diffusion)

Question 21

What is transpiration?

Answer 21

• Movement/loss of water vapour from leaves

- Water vapour evaporates and diffuses out of the stomata

Question 22

Why is there more stomata at the bottom pf a leaf compared to the top?

Answer 22

• Prevents evaporation of water vapour from the leaf

- Decreases transpiration (water loss)

Question 23

How is transpiration measured?

Answer 23

• Using a potometer

Question 24

What is the role of companion cells?

Answer 24

Controls movement of sucrose (has nucleus unlike phloem tube)