photosynthesis (2.18-2.23)

Question 1

explain the effect of changing distance of the lamp on the rate of photosynthesis of pondweed in both concentration of carbon dioxide

Answer 1

-as distance from the lamp increases, light intensity decreases
-decreases the rate of photosynthesis/number of bubbles
- as less energy absorbed
rate is constant until limiting factors
use examples

Question 2

explain the effect of magnesium and nitrate on the growth of the seedlings

Answer 2

-magnesium ions increase chlorophyll/chloroplasts
- so more photosynthesis
-which produces carbohydrates/glucose/starch
-nitrate ions for amino acids
-for protein- for growth

Question 3

how could you test a leaf for starch

Answer 3

boil in ethanol, boil in water
test with iodine
orange –> blue black if starch is present

Question 4

describe how the structure of a leaf is adapted for photosynthesis

Answer 4

-leaf is flat and wide- large surface area for diffusion
-leaf is thin- short diffusion distance
-upper epidermis- transparent to allow light through
-palisade mesophyll- contains many chloroplasts near surface to absorb light
- stomata to absorb carbon dioxide
-xylem brings water for photosynthesis

Question 5

how is the palisade mesophyll adapted for photosynthesis

Answer 5

palisade is near the top- to absorb as much light as possible
palisade contain many chloroplasts- to absorb as much light as possible
palisade are long and rectangular to absorb as much light as possible

Question 6

how is the spongy mesophyll adapted for photosynthesis

Answer 6

near the bottom for absorption of CO2
less densely packed/have air spaces for gas exchange/diffusion/movement of gases

Question 7

what is the word equation for photosynthesis

Answer 7

carbon dioxide + water—> oxygen + glucose

Question 8

what is the chemical equation for photosynthesis

Answer 8

6CO2 + 6H2O → C6H12O6 + 6O2