Life processes are the essential biological functions that maintain body functions and
keep living organisms alive.
Examples: Nutrition, Respiration, Transportation and Excretion.
Nutrition
Nutrition is the process of taking nutrients (carbohydrates, proteins, vitamins &
minerals) from food and using them for energy and growth.
Autotrophic Nutrition Heterotrophic Nutrition
• Organisms prepare their own food using • Organisms depend on other organisms
simple inorganic substances like CO and₂ for food to survive and get it from plants,
water in the presence of sunlight. animals and decaying matter.
• Example: Green plants • Examples: Humans and Amoeba
Heterotrophic Nutrition
Saprophytic Nutrition Parasitic Nutrition Holozoic Nutrition
• Organisms obtain food from • Organisms obtain food • Organisms take in solid
dead and decaying organic from another living food, which is then
matter. organism without killing it. digested and absorbed
• Example: fungi (bread • Example: Mosquito and as nutrients.
mould), mushrooms and yeast Tapeworm • Examples: Humans &
animals
→ Holozoic nutrition involves ingestion, digestion, absorption, assimilation and egestion.
# Nutrition in plants:
□ Photosynthesis:
The process in which green plants convert simple inorganic substances like CO and ₂
₆ ₁₂ ₆
water into glucose (C H O ) in the presence of sunlight and chlorophyll.
Conditions necessary for
phosynthesis are sunlight,
₂,
CO water and chlorophyll
□ Steps of Photosynthesis:
• Absorption of light energy by chlorophyll.
• Conversion of light energy into chemical energy and splitting of water molecules into
hydrogen and oxygen.
• Reduction of carbon dioxide to form carbohydrates (glucose).
□ Chloroplasts: In plants → glucose (food) is stored in the form of starch
• Chloroplasts are small organelles found in plant cells. They contain the green pigment
chlorophyll, which absorbs sunlight for photosynthesis.
• Chloroplasts are the site where photosynthesis takes place in plants.
, □ Internal Structure of a Leaf:
Prevents water loss and protects the
leaf surface
Protects internal leaf tissues and reduces
water loss
Contains stomata for gas exchange
Allows diffusion of gases inside the leaf
□ Stomata:
Tiny pores present on the surface of leaves that help in gas exchange (intake of CO and ₂
₂
release of O ) and transpiration (loss of water vapour from surface of leaves).
Control the opening and closing of stomata
Guard cells ₂ → Guard cells swell (open stomata)
Chloroplast • Absorb H O
• Lose H₂O → Guard cells shrink (closed stomata)
Performs photosynthesis using sunlight
Stomatal pore
Control gas exchange
open stomatal pore closed stomatal pore
□ Nutrition in Amoeba: Engulfs food particles
• Ingestion: Engulfing food using pseudopodia.
• Digestion: Breaking down food inside food vacuole.
• Absorption: Nutrients absorbed into cytoplasm.
• Assimilation: Utilized of nutrients for growth and energy.
• Egestion: Removal of undigested waste outside the body.
Helps in digestion of food by breaking down
complex substances into simple substances
keep living organisms alive.
Examples: Nutrition, Respiration, Transportation and Excretion.
Nutrition
Nutrition is the process of taking nutrients (carbohydrates, proteins, vitamins &
minerals) from food and using them for energy and growth.
Autotrophic Nutrition Heterotrophic Nutrition
• Organisms prepare their own food using • Organisms depend on other organisms
simple inorganic substances like CO and₂ for food to survive and get it from plants,
water in the presence of sunlight. animals and decaying matter.
• Example: Green plants • Examples: Humans and Amoeba
Heterotrophic Nutrition
Saprophytic Nutrition Parasitic Nutrition Holozoic Nutrition
• Organisms obtain food from • Organisms obtain food • Organisms take in solid
dead and decaying organic from another living food, which is then
matter. organism without killing it. digested and absorbed
• Example: fungi (bread • Example: Mosquito and as nutrients.
mould), mushrooms and yeast Tapeworm • Examples: Humans &
animals
→ Holozoic nutrition involves ingestion, digestion, absorption, assimilation and egestion.
# Nutrition in plants:
□ Photosynthesis:
The process in which green plants convert simple inorganic substances like CO and ₂
₆ ₁₂ ₆
water into glucose (C H O ) in the presence of sunlight and chlorophyll.
Conditions necessary for
phosynthesis are sunlight,
₂,
CO water and chlorophyll
□ Steps of Photosynthesis:
• Absorption of light energy by chlorophyll.
• Conversion of light energy into chemical energy and splitting of water molecules into
hydrogen and oxygen.
• Reduction of carbon dioxide to form carbohydrates (glucose).
□ Chloroplasts: In plants → glucose (food) is stored in the form of starch
• Chloroplasts are small organelles found in plant cells. They contain the green pigment
chlorophyll, which absorbs sunlight for photosynthesis.
• Chloroplasts are the site where photosynthesis takes place in plants.
, □ Internal Structure of a Leaf:
Prevents water loss and protects the
leaf surface
Protects internal leaf tissues and reduces
water loss
Contains stomata for gas exchange
Allows diffusion of gases inside the leaf
□ Stomata:
Tiny pores present on the surface of leaves that help in gas exchange (intake of CO and ₂
₂
release of O ) and transpiration (loss of water vapour from surface of leaves).
Control the opening and closing of stomata
Guard cells ₂ → Guard cells swell (open stomata)
Chloroplast • Absorb H O
• Lose H₂O → Guard cells shrink (closed stomata)
Performs photosynthesis using sunlight
Stomatal pore
Control gas exchange
open stomatal pore closed stomatal pore
□ Nutrition in Amoeba: Engulfs food particles
• Ingestion: Engulfing food using pseudopodia.
• Digestion: Breaking down food inside food vacuole.
• Absorption: Nutrients absorbed into cytoplasm.
• Assimilation: Utilized of nutrients for growth and energy.
• Egestion: Removal of undigested waste outside the body.
Helps in digestion of food by breaking down
complex substances into simple substances
