CHAPTER
LIFE PROCESSES
5
TW CHAPTER ATA GLANCE
Movement of various types can be taken as an evidence of
being alive.
transport of materials within the body
Maintenance of life requires processes like nutrition, respiration,
and excretion of waste products.
organism from a non-living one.
The ability toperform the basic life processes distinguishes a livingmaintain and sustain life are called
organisms in order to
Ihe vital processes carried out by living the various life processes.
Life Processes. Molecular movements are essential to carry out
LIFE PROCESSES
Circulation Excretion Reproduction
Growth Nutrition Respiration
various life processes. In unicellular
In multicellular organisms, specialised body parts perform the
organisms, no such specialised organs are present.
obtained from carbon-based food sources
Energy required to carry out the different life processes is
through nutrition.
by other organisms.
Allheterotrophic nutrition involves the intake of complex material prepared
classified into two major categories
Depending on the mode of obtaining nutrition, organisms are
as autotrophs and heterotrophs.
NUTRITION
Autotrophic nutrition Heterotrophic nutrition
Autotrophs Heterotrophs
Can prepare their own food. Depend on plants or their animals for
their food. Ex : Animals and Fungi
Ex : Green plants and some bacteria
substances like carbon dioxide
i) Autotrophs can prepare their own food from simple inorganic
and water (Ex : green plants,some bacteria).
the autotrophs for
Heterotrophs cannot synthesize their own food and are dependent on
animals).
obtaining complex organic substances for nutrition (Ex:
their own food is
Autotrophicnutrition : The mode of nutrition in which organisms can prepare
called Autotrophicnutrition.
an external
It involves the intake of simple inorganic materials from the environment and using
energy source like the Sun to synthesise complex high-energy organic material.
carbon dioxide, water
Green plants prepare their food by the process of photosynthesis, by using
as a by
and sunlight with the help of chlorophyll. During photosynthesis, oxygen is liberated
product.
Sunlight
6C0, +12H,0 ChlorophyiH,0, +6H,0+60,‘
VARSITY EDUCATION MANAGEMENT PVT. LTD. 5
, X
CLASS - CBSE BIOLOGY COURSE MATERIAI
Main Events of photosynthesis are :
Absorption of light energy by chlorophyll
Conversion of light energy into chemical energy by splitting (breaking) of water molecules into
hydrogen and oxygen.
Reduction of carbon dioxide to carbohydrates.
In the light (light dependent) reaction of photosynthesis, light energy is fixed and converted to
chemical energy i.e. ATP. During this phase, water molecules are split into hydrogen and oxygen
(photolysis).
Carbon dioxide is reduced tocarbohydrates in the dark (light independent) phase of
(Carbon fixation or Calvin cycle). photosynthesis
Heterotrophic nutrition :
The mode of nutrition in which organisms can't prepare their
own food and depend on others for
their food is called heterotrophic nutrition.
HETEROTROPHIC NUTRITION
Holozoic Parasitic
Saprophytic
Consuming solid or Living inside or outside other
liquid food and digest it organisms (host) and derive nutrition Feed is on dead and
inside the body. from them. decaying organic matter.
Ex : Animals Ex:Cuscuta, ticks, etc. Ex :Fungi and bacteria
Heterotrophs may be herbivores, carnivores, parasites or
Nutrition in single celled organisms : saprophytes.
In Amoeba, digestion takes place in the
food vacuole, engulfing the food by its pseudopodia.
Amoeba
Pseudopodia Capture food Takes food into food vacuole
Diffusion of digested food into
cytoplasm Digestion of food in the food vacuole
Undigested food
Move to surface of cell and
is
thrown out.
In Paramoecium, tiv uell
has
adefinite shape and
to this spot by the food is taken in at a specifie
movement of cilia (cover the entire
surtace of the cell). spot. Food is moveu
Nutrition in Human Beings :
In human beings, the
the digested food is food eaten is broken down by various steps along
In human beings, absorbed in the small intestine to be sent to all cells inthe alimentary canal anu
digestion of food takes place in the the body.
and glands. alimentary canal, made up of various orgas
LIFE PROCESSES
5
TW CHAPTER ATA GLANCE
Movement of various types can be taken as an evidence of
being alive.
transport of materials within the body
Maintenance of life requires processes like nutrition, respiration,
and excretion of waste products.
organism from a non-living one.
The ability toperform the basic life processes distinguishes a livingmaintain and sustain life are called
organisms in order to
Ihe vital processes carried out by living the various life processes.
Life Processes. Molecular movements are essential to carry out
LIFE PROCESSES
Circulation Excretion Reproduction
Growth Nutrition Respiration
various life processes. In unicellular
In multicellular organisms, specialised body parts perform the
organisms, no such specialised organs are present.
obtained from carbon-based food sources
Energy required to carry out the different life processes is
through nutrition.
by other organisms.
Allheterotrophic nutrition involves the intake of complex material prepared
classified into two major categories
Depending on the mode of obtaining nutrition, organisms are
as autotrophs and heterotrophs.
NUTRITION
Autotrophic nutrition Heterotrophic nutrition
Autotrophs Heterotrophs
Can prepare their own food. Depend on plants or their animals for
their food. Ex : Animals and Fungi
Ex : Green plants and some bacteria
substances like carbon dioxide
i) Autotrophs can prepare their own food from simple inorganic
and water (Ex : green plants,some bacteria).
the autotrophs for
Heterotrophs cannot synthesize their own food and are dependent on
animals).
obtaining complex organic substances for nutrition (Ex:
their own food is
Autotrophicnutrition : The mode of nutrition in which organisms can prepare
called Autotrophicnutrition.
an external
It involves the intake of simple inorganic materials from the environment and using
energy source like the Sun to synthesise complex high-energy organic material.
carbon dioxide, water
Green plants prepare their food by the process of photosynthesis, by using
as a by
and sunlight with the help of chlorophyll. During photosynthesis, oxygen is liberated
product.
Sunlight
6C0, +12H,0 ChlorophyiH,0, +6H,0+60,‘
VARSITY EDUCATION MANAGEMENT PVT. LTD. 5
, X
CLASS - CBSE BIOLOGY COURSE MATERIAI
Main Events of photosynthesis are :
Absorption of light energy by chlorophyll
Conversion of light energy into chemical energy by splitting (breaking) of water molecules into
hydrogen and oxygen.
Reduction of carbon dioxide to carbohydrates.
In the light (light dependent) reaction of photosynthesis, light energy is fixed and converted to
chemical energy i.e. ATP. During this phase, water molecules are split into hydrogen and oxygen
(photolysis).
Carbon dioxide is reduced tocarbohydrates in the dark (light independent) phase of
(Carbon fixation or Calvin cycle). photosynthesis
Heterotrophic nutrition :
The mode of nutrition in which organisms can't prepare their
own food and depend on others for
their food is called heterotrophic nutrition.
HETEROTROPHIC NUTRITION
Holozoic Parasitic
Saprophytic
Consuming solid or Living inside or outside other
liquid food and digest it organisms (host) and derive nutrition Feed is on dead and
inside the body. from them. decaying organic matter.
Ex : Animals Ex:Cuscuta, ticks, etc. Ex :Fungi and bacteria
Heterotrophs may be herbivores, carnivores, parasites or
Nutrition in single celled organisms : saprophytes.
In Amoeba, digestion takes place in the
food vacuole, engulfing the food by its pseudopodia.
Amoeba
Pseudopodia Capture food Takes food into food vacuole
Diffusion of digested food into
cytoplasm Digestion of food in the food vacuole
Undigested food
Move to surface of cell and
is
thrown out.
In Paramoecium, tiv uell
has
adefinite shape and
to this spot by the food is taken in at a specifie
movement of cilia (cover the entire
surtace of the cell). spot. Food is moveu
Nutrition in Human Beings :
In human beings, the
the digested food is food eaten is broken down by various steps along
In human beings, absorbed in the small intestine to be sent to all cells inthe alimentary canal anu
digestion of food takes place in the the body.
and glands. alimentary canal, made up of various orgas
