Plant nutrition

Question 1

what is photosynthesis ?

Answer 1

plants synthesise carbohydrates from raw materials using energy from the light

Question 2

word equation for photosynthesis is :

Answer 2

carbon dioxide + water = oxygen + glucose

Question 3

what is present for photosynthesis to occur ?

Answer 3

chlorophyll , light

Question 4

what is chlorophyll ?

Answer 4

green pigment that is found in chloroplast which absorbs light for photosynthesis

Question 5

function of chlorophyll :

Answer 5

transfer of energy from light to chemical energy for the synthesis of carbohydrates

Question 6

chemical equation for photosynthesis :

Answer 6

6CO2 + 6H20 →C6H12O6 + 6CO2

Question 7

conversion of glucose to other compounds : (Hint they’re 6 )

Answer 7

glucose- release energy
sucrose- for transport
chlorophyll - absorb light for photosynthesis
amino acids -to make protein for growth
starch -to store glucose
nectar - to attract pollinators
cellulose - build cell walls

Question 8

why is nitrogen important ?

Answer 8

for making amino acids for growth

Question 9

why is magnesium important ?

Answer 9

for making chlorophyll for photosynthesis

Question 10

How to find out need for light in photosynthesis :

Answer 10

• Destarch a plant.
• Cover part of a leaf with lightproof paper/foil.
• Make a drawing of the leaf.
• Place the plant in bright light for several hours.
• Test the leaf for starch using the 4-step starch test.
• Make another drawing of the -leaf.

Question 11

How to find out need for chlorophyll in photosynthesis :

Answer 11

• Take a potted plant with variegated leaves like croton and keep it in a dark region, away from sunlight for 3 days.
  -This will halt photosynthesis and de-starch the plant.
  -Then keep the plant facing the sunlight for 6 to 8 hours.
  -The plant can now carry out photosynthesis and produce بلفstarch.

Question 12

How to find out need for carbon dioxide in photosynthesis :

Answer 12

-Expose one leaf to sodium hydroxide, which will absorb carbon dioxide from the surrounding air.
-Expose another leaf to water (control experiment), which will not absorb carbon dioxide from the surrounding air.
-Place the plant in bright light for several hours.

Question 13

test for starch :

Answer 13

• cut leaf from plant placed in a dark room .
• boil the leaf in water for a min
• put in alcohol and place test tube in water for a min
• put in warm water
• check with iodine
• +ve = blue/black
• _ve = red/brown

Question 14

light intensity / CO2 / temp are ______ to rate of photosynthesis

Answer 14

directly proportional

Question 15

What is the hydrogen carbonate indicator in photosynthesis experiment?

Answer 15

After exposing the vial to a light source, the colour in the solution should change from yellow/orange to purple as photosynthesis absorbs the CO 2 and the pH rises. After placing the vial in the dark, you should observe the colour in the vial change from purple to yellow/orange as respiration occurs and the pH falls.

Question 16

what are limiting factors ?

Answer 16

factors which controls the rate of reaction when present n low amount

Question 17

limiting factors of photosynthesis are :

Answer 17

light intensity.
carbon dioxide concentration.
temperature.

Question 18

what are leaf features which are considerd leaf adaptations :

Answer 18

large surface areas ,and are thin that it can absorb a lot of light. Its top surface is protected from water loss and weather damage by a waxy layer. The upper part of the leaf is where the light falls, and it contains a type of cell called a palisade cell. This is adapted to absorb a lot of light.

Question 19

epidermis function :

Answer 19

reduce quantity of water vapour escaping , no chloroplast for photosynthesis