Plants

Question 1

What is the word and symbol equation for photosynthesis?

Answer 1

• Carbon dioxide + water (+ light and chloropyll) —–> glucose + oxygen
• 6CO₂ + 6H₂0 ———-> C₆H₁₂O₆ + 6O₂

Question 2

How are the leaves of a plant adapted to their function?

Answer 2

• Large surface area to absorb more light
• Thin, short distance for carbon dioxide to diffuse into the cells
• Chlorophyll, absorbs sunlight and transfers energy into chemicals
• Network of veins, support leaf and to transport water and carbohydrates
• Stomata allow carbon dixode to diffuse into the cell

Question 3

What is the function of the waxy cuticle?

Answer 3

• Reduces water loss by evaporation and acts as a barrier to the entry of pathogens

Question 4

What is the function of the stomata?

Answer 4

• Allow carbon dioixde to diffuse into the leaf
• Allow oxygen and water vapour to diffuse out

Question 5

How is the upper epidermis adapted to its function?

Answer 5

• It is realtively transparent so it alllow light to pass through to the chloroplasts.

Question 6

What is the function of the spongy mesophyll?

Answer 6

• It is the main gas exchange surface of the leaf

Question 7

What is the function of the xylem?

Answer 7

• To supply the leaf water and mineral ions

Question 8

What is the function of the phloem?

Answer 8

• To carry the products of photosynthesis away from the mesophyll cells

Question 9

What is the compensation point?

Answer 9

• The amunt of light intesnity on the light curve where the rate of photosynthesis is equal to the rate of respiration

Question 10

How does light intensity affect the rate of photosynthesis?

Answer 10

• Increasing the light intensity will boost the speed of photosynthesis.

Question 11

How does the temperature affect the rate of photsynthesis?

Answer 11

• If it gets too cold, the rate of photosynthesis will decrease.
• Plants cannot photosynthesise if it gets too hot.

Question 12

How does the carbon dioxide levels affect the rate of photosynthesis?

Answer 12

• Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air.
• Even if there is plenty of light, a plant cannot photosynthesise if there is insufficient carbon dioxide.

Question 13

What are the uses for glucose?

Answer 13

• Stored as starch and lipids for use in respiration
• Used to produce cellulose, which stregthens cell wall
• Used to produce proteins

Question 14

What is the use of nitrate in a plant?

Answer 14

• Making amino acids, proteins, chlorophyll, DNA

Question 15

What happens in a plant if there is a defiency of nitrates?

Answer 15

• Older leaves turn yellow ad die prematurely
• Plant is stunted

Question 16

What are the uses of phosphates in plants?

Answer 16

• Making nucleic acids, ATP, phospholids
• Part of cell membranes

Question 17

What happens in a plant if there is a defiency of phosphates?

Answer 17

• Poor root growth
• Younger leaves turn purple (veins)

Question 18

What are the uses of potassium in plants?

Answer 18

• Enzyme activation
• Water balance
• Ion balance
• Stomatal opening

Question 19

What happens in a plant if there is a defiency of potassium?

Answer 19

• Leaves turn yellow with dead spots

Question 20

What is the use of magnesium in plants?

Answer 20

• In chlorophyll
• Required by many enzymes
• Stablises ribosomes

Question 21

What happens in a plant if there is a defiency of magnesium?

Answer 21

• Leaves turn yellow