(i) Photosynthesis is a process by which autotrophic organisms like green plants, algal and chlorophyll containing bacteria utilize the energy from sunlight using CO₂ and H₂O to synthesize their own food.
(ii) It occurs in the chloroplasts of the cell.
\(6 \mathrm{CO}_2+12 \mathrm{H}_2 \mathrm{O} \underset{\text { Chlorophyll }}{\stackrel{\text { Light }}{\longrightarrow}} \mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+6 \mathrm{H}_2 \mathrm{O}+6 \mathrm{O}_2 \uparrow\)

The three basic tissue systems is flowering plants are
(i) Dermal or Epidermal tissue system
(ii) Ground tissue system
(iii) Vascular tissue system

(i) The tissue present between the upper and the lower epidermis is called mesophyll.
(ii) Mesophyll cells contain chloroplasts.
(iii) In dicot leaf, the mesophyll is differentiated into palisade parenchyma and spongy parenchyma.
(iv) Palisade cells do not have intercellular spaces and take active part in photosynthesis.
(v) Whereas, spongy parenchyma cells have large intercellular spaces and helps in gaseous exchange.

(i) A large number of vascular bundles are present in dicot stem.
(ii) They are arranged in the form of a ring around the pith.
(iii) Vascular bundles are conjoint, collateral, endarch and open.

a) Difference between Light dependent and light independent reactions: 

 b) Reactants and End products:

c) Place of occurrence:
(i) Light Dependent : Thylakoid membrane (grana) of the chloroplast.
(ii) Light Independent : Stroma of the chloroplast.

The 3 stages of erobic respiration are Glycolysis, Krebs cycle and Electron Transport Chain.
(a) Glycolysis (Glucose splitting):
(i) Glycolysis takes place in the cytoplasm of the cell.
(ii) It is the breakdown of one molecule of glucose (6 carbon) into two molecules of Pyruvic acid (3 carbon).
(b) Krebs Cycle:
(i) This cycle occurs in mitochondrial matrix.
(ii) At the end of glycolysis, 2 molecules of pyruvic acid enter into mitochondria.
(iii) The oxidation of pyruvic acid into CO₂ and water takes place.
(iv) It is also called Tricarboxylic Acid Cycle (TAC).
(c) Electron Transport Chain:
(i) NADH₂ and FADH₂ molecules formed during glycolysis and Krebs cycle are oxidised to NAD⁺ and FAD⁺ to release the energy through electrons.
(ii) These electrons move through the electron transport chain and release energy.
(iii) This energy is used by ADP to synthesize ATP.
(iv) This is called oxidative phosphorylation.
(v) In this process O₂ gets reduced to water.
(vi) \(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+6 \mathrm{O}_{2} \rightarrow 6 \mathrm{CO}_{2}+6 \mathrm{H}_{2} \mathrm{O}+\mathrm{ATP}\)

a) Monocot root and dicot root

b) Aerobic respiration and anaerobic Respiration:

The light-dependent reactions occur in the thylakoids (grana) and the light independent reactions (Calvin cycle) occur in the stroma.

(A) Light and dark reaction of photosynthesis:
(i) The light-dependent reactions require light and water and produce ATP and NADPH₂.
(ii) The light-independent reactions require carbon dioxide and this CO₂ is reduced to carbohydrates.
(B) During photosynthesis, two important processes are taking place:
(i) The light reactions and the dark reactions (Calvin cycle).
(ii) The light reactions use light to synthesize ATP and NADPH₂.
(iii) The Calvin cycle uses these reactants to produce sugar from additional CO₂ molecule.
(iv) This cycle then produces \(\mathrm{NAP}^{+}, \mathrm{ADP}+\mathrm{Pi}\) (Inorganic phosphate) which is used in the light reactions, with H₂O molecules, to produce ATP and NADPH₂ again.