Online Notes on Chapter = 6 ( life processes) Part 1

This is Online Notes on Chapter = 6 ( life processes)  Part 1 for 
preparation of CBSE BOARD Examination, NTSE etc.

All living things perform certain life processes like growth, excretion, respiration,
circulation etc.
All the processes like respiration, digestion, which together keep the living organisms
alive and perform the job of body maintenance are called life processes.

Raw Materials for Photosynthesis :
• Sunlight
• Chlorophyll → Sunlight absorbed by chlorophyll
• CO2 → Enters through stomata and oxygen (O2) is released as by-product through
stomata on leaf.
• Water → Water + dissolved minerals like nitrogen, phosphorus etc. are taken up by the
roots of the soil.
Site of Photosynthesis :
Chloroplast in the leaf, chloroplast contain chlorophyll (green pigment).
Main Events of Photosynthesis :
• Absorption of light energy by chlorophyll
• Conversion of light energy into chemical energy + splitting (breaking) of water into
hydrogen and oxygen
• Reduction of CO2 to carbohydrates
Stomata : Tiny pores present on the surface of the leaves.
Functions :
(a) Exchange of gases O2/CO2.
(b) Loses large amount of water (water vapour) during transpiration.

How do organisms obtain their food
Unicellular/Single celled organisms : Food is taken up through entire surface.
Example : (i) Amoeba
(ii) Paramaecium

Different organisms utilize different nutritional processes as it depends upon the source
of carbon from where the food is taken.

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