List the events that occur during photosynthesis in brief.

During photosynthesis the following events occur:
(i) Absorption of light energy by the chlorophyll pigment.
(ii) Conversion of light energy into chemical energy.
(iii) Splitting of water molecules into hydrogen and oxygen.
(iv) Reduction of carbon dioxide into carbohydrates.

272 Views

State the part played by each of the following in photosynthesis:
(a) Water (b)Chlorophyll (c) Stomata.


(a) Water: Water (H2O) undergo photosynthesis in light reaction.

H2O → 2H+ + O + 2e
O + O → O2 ↑

As a result ATP and NADPH are formed which are used in formation of carbohydrates from CO2


(a) Water: Water (H2O) undergo photosynthesis in light reaction.
H2O

Water also releases O2 which is given out during photosynthesis.

(b) Chlorophyll: It traps solar (light) energy and utilises it in fixing oxides of carbon (CO2) and hydrogen (H2O) as carbohydrates.

(c) Stromata: They help in exchange of gases. Carbon dioxide needed in photosynthesis is taken in through stomata. Oxygen produced in photosynthesis is given out through stomata.

507 Views

A parrot is green in colour yet it is not an autotroph like green plants. What is the reason?


Like green plants, a parrot does not contain chlorophyll pigment which can absorb and convert light energy into chemical energy that can be used to prepare their own food. The green color of parrot is not due to chlorophyll.
533 Views

Advertisement

Draw a labelled diagram of cross-section of a leaf lamina to show chloroplasts.



Fig. 6.2. Cross-section of a leaf

Fig. 6.2. Cross-section of a leaf

624 Views

Advertisement
Do all events during photosynthesis take place one after the other immediately? Give an example.

Not necessarily. For example, desert plants take up carbon dioxide at night and prepare an intermediate compound. This intermediate compound is acted upon by the energy absorbed during the day by the chlorophyll.
1331 Views

Advertisement