Photosynthesis

Question 1

What is photosynthesis

Answer 1

photosynthesis is when plants produce glucose from simpler molecules using light energy

Question 2

Word equation for photosynthesis

Answer 2

Carbon dioxide + water = Glucose + Oxygen

Endothermic reaction

Question 3

What are the main factors affecting photosynthesis

Answer 3

Light intensity
Carbon dioxide concentration
temperature
(water content)

Question 4

Explain the practical about photosynthesis

Answer 4

place a test tube with boiling water 10cm away from the light source

place the algal beads in the water

put a fixed volume of bicarbonate indicator in the boiling water

record the PH and colour of the solution and start a timer for 30 mins

After 30 mins record the PH and colour again

Repeat the experiment with the light source different distances from the test tube of boiling water

plot a graph showing results

Question 5

Safety precautions for the practical (hazards)

Answer 5

Wear gloves and goggles for boiling water
keep water away from electrical wires
Lamp may get hot

Question 6

What is a limiting factor

Answer 6

Something that is limiting the rate of photosynthesis for ex. not enough light for the reaction to occur

Question 7

How are root hair cells adapted to their function

Answer 7

Large surface area so water and mineral ions can be absorbed quicker

Thin cell walls so the flow of water into the cells is not slowed down

Do not have chloroplasts because they are underground

Question 8

Functions of Xylem and Phloem cells

Answer 8

Xylem cells used to transport water and mineral ions from the roots to the stem and leaf

Phloem used to carry sucrose up and down the phloem cells

Question 9

Adaptations of Xylem and phloem

Answer 9

Xylem cells are dead and this creates long empty vessels for water to flow easily . thick side walls made of lignin so no water can burst from the xylem and lignin helps support the structure of the plant . Xylem have no nucleus, cytoplasm, vacuole or chloroplasts.

Phloem cells have companion cells and mitochondria from the companion cells provide energy to the phloem cells. Have sieve plates that help dissolved sugars travel through the interior of the cell.