CLASS 10
BIOLOGY
LIFE
PROCESSES
Comprehensive
Master
Revision Notes
Strictly
Based
on
Page 1
, 1. Introduction to Life Processes
Life processes are the basic essential activities performed by living organisms to maintain
their life on earth and to perform their day-to-day activities. The fundamental life processes
include nutrition, respiration, transportation, excretion, control and coordination, growth,
and reproduction.
Criteria for Living: Movement is considered one of the most important criteria.
While visible movement is easy to spot, molecular movements (invisible to the
naked eye) are essential for life as they repair and maintain structures.
2. Nutrition
Nutrition is the process of intake of nutrients and its utilization by an organism in biological
activities. There are two main modes of nutrition:
A. Autotrophic Nutrition
Organisms synthesize their own food from simple inorganic materials like CO2 and water in
the presence of sunlight and chlorophyll. Example: Green plants and some bacteria.
Photosynthesis Equation:
6CO₂ + 12H₂O + Sunlight + Chlorophyll → C₆H₁₂O₆ + 6O₂ + 6H₂O
Steps of Photosynthesis:
1. Absorption of light energy by chlorophyll.
2. Conversion of light energy to chemical energy and splitting of water
molecules into hydrogen and oxygen.
3. Reduction of carbon dioxide to carbohydrates (Glucose).
Page 2
BIOLOGY
LIFE
PROCESSES
Comprehensive
Master
Revision Notes
Strictly
Based
on
Page 1
, 1. Introduction to Life Processes
Life processes are the basic essential activities performed by living organisms to maintain
their life on earth and to perform their day-to-day activities. The fundamental life processes
include nutrition, respiration, transportation, excretion, control and coordination, growth,
and reproduction.
Criteria for Living: Movement is considered one of the most important criteria.
While visible movement is easy to spot, molecular movements (invisible to the
naked eye) are essential for life as they repair and maintain structures.
2. Nutrition
Nutrition is the process of intake of nutrients and its utilization by an organism in biological
activities. There are two main modes of nutrition:
A. Autotrophic Nutrition
Organisms synthesize their own food from simple inorganic materials like CO2 and water in
the presence of sunlight and chlorophyll. Example: Green plants and some bacteria.
Photosynthesis Equation:
6CO₂ + 12H₂O + Sunlight + Chlorophyll → C₆H₁₂O₆ + 6O₂ + 6H₂O
Steps of Photosynthesis:
1. Absorption of light energy by chlorophyll.
2. Conversion of light energy to chemical energy and splitting of water
molecules into hydrogen and oxygen.
3. Reduction of carbon dioxide to carbohydrates (Glucose).
Page 2
