NCERT Notes, Exercise 6: Life Processes, Class 10 (Science) Notes - Class 10

 Page 1


AK
50 X – Science
CHAPTER – 6
LIFE PROCESSES
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.
Examples :
Kinds of nutrition in which in organic
materials like CO
2
, water etc are utilized to
prepare organic food by the process of
photosyntheses
Eg. Green Plants
Kinds of nutrition in which in organisms do
not possess the ability to synthesize their
own food. They depend on autotrophs for
their food supply directly or indirectly.
eg. Animals, Fungi
Page 2


AK
50 X – Science
CHAPTER – 6
LIFE PROCESSES
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.
Examples :
Kinds of nutrition in which in organic
materials like CO
2
, water etc are utilized to
prepare organic food by the process of
photosyntheses
Eg. Green Plants
Kinds of nutrition in which in organisms do
not possess the ability to synthesize their
own food. They depend on autotrophs for
their food supply directly or indirectly.
eg. Animals, Fungi
AK
51 X – Science
Autotrophic Nutrition :
The organisms which carry out autotrophic nutrition are called autotrophs (green
plants)
Autotrophic nutrition is fulfilled by the process by which autotrophs take in CO
2
and
H
2
O and convert these into carlohydrates in the presence of chlorophyll, sunlight is
called PHOTOSYNTHESIS
Equation :
Raw Materials for Photosynthesis :
q Sunlight
q Chlorophyl ? Sunlight absorbed by chlorophyll
q CO
2
? enters through Stomata, and Oxygen (O
2
) is released as by product
through stomata on leaf.
q Water ? water + dissolved minerals like Nitrogen phosphorous etc are taken
up by the roots from the soil.
Site of Photosynthesis :
Chloroplast in the leaf. Chloroplast contain chlorophyll. (green pigment)
Main Events of Photosynthesis :
q Absorption of light energy by chlorophyll
q Conversion of light energy into chemical energy + splitting (breaking) of water
into hydrogen and oxygen.
q Reduction of CO
2
to carbohydrates.
STOMATA : Tiny pores present on the surface of the leaves
FUNCTIONS :
(i) Exchange of gases O
2
/CO
2
(ii) Loses large amount of water [water vapour] during transpiration.
Page 3


AK
50 X – Science
CHAPTER – 6
LIFE PROCESSES
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.
Examples :
Kinds of nutrition in which in organic
materials like CO
2
, water etc are utilized to
prepare organic food by the process of
photosyntheses
Eg. Green Plants
Kinds of nutrition in which in organisms do
not possess the ability to synthesize their
own food. They depend on autotrophs for
their food supply directly or indirectly.
eg. Animals, Fungi
AK
51 X – Science
Autotrophic Nutrition :
The organisms which carry out autotrophic nutrition are called autotrophs (green
plants)
Autotrophic nutrition is fulfilled by the process by which autotrophs take in CO
2
and
H
2
O and convert these into carlohydrates in the presence of chlorophyll, sunlight is
called PHOTOSYNTHESIS
Equation :
Raw Materials for Photosynthesis :
q Sunlight
q Chlorophyl ? Sunlight absorbed by chlorophyll
q CO
2
? enters through Stomata, and Oxygen (O
2
) is released as by product
through stomata on leaf.
q Water ? water + dissolved minerals like Nitrogen phosphorous etc are taken
up by the roots from the soil.
Site of Photosynthesis :
Chloroplast in the leaf. Chloroplast contain chlorophyll. (green pigment)
Main Events of Photosynthesis :
q Absorption of light energy by chlorophyll
q Conversion of light energy into chemical energy + splitting (breaking) of water
into hydrogen and oxygen.
q Reduction of CO
2
to carbohydrates.
STOMATA : Tiny pores present on the surface of the leaves
FUNCTIONS :
(i) Exchange of gases O
2
/CO
2
(ii) Loses large amount of water [water vapour] during transpiration.
AK
52 X – Science
How do organisms obtain their food
Unicellular / single celled organism : food is taken up through entire surface.
Example : (i) Amoeba. (ii) Paramaecium
Page 4


AK
50 X – Science
CHAPTER – 6
LIFE PROCESSES
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.
Examples :
Kinds of nutrition in which in organic
materials like CO
2
, water etc are utilized to
prepare organic food by the process of
photosyntheses
Eg. Green Plants
Kinds of nutrition in which in organisms do
not possess the ability to synthesize their
own food. They depend on autotrophs for
their food supply directly or indirectly.
eg. Animals, Fungi
AK
51 X – Science
Autotrophic Nutrition :
The organisms which carry out autotrophic nutrition are called autotrophs (green
plants)
Autotrophic nutrition is fulfilled by the process by which autotrophs take in CO
2
and
H
2
O and convert these into carlohydrates in the presence of chlorophyll, sunlight is
called PHOTOSYNTHESIS
Equation :
Raw Materials for Photosynthesis :
q Sunlight
q Chlorophyl ? Sunlight absorbed by chlorophyll
q CO
2
? enters through Stomata, and Oxygen (O
2
) is released as by product
through stomata on leaf.
q Water ? water + dissolved minerals like Nitrogen phosphorous etc are taken
up by the roots from the soil.
Site of Photosynthesis :
Chloroplast in the leaf. Chloroplast contain chlorophyll. (green pigment)
Main Events of Photosynthesis :
q Absorption of light energy by chlorophyll
q Conversion of light energy into chemical energy + splitting (breaking) of water
into hydrogen and oxygen.
q Reduction of CO
2
to carbohydrates.
STOMATA : Tiny pores present on the surface of the leaves
FUNCTIONS :
(i) Exchange of gases O
2
/CO
2
(ii) Loses large amount of water [water vapour] during transpiration.
AK
52 X – Science
How do organisms obtain their food
Unicellular / single celled organism : food is taken up through entire surface.
Example : (i) Amoeba. (ii) Paramaecium
AK
53 X – Science
NUTRITION IN HUMAN BEINGS
The human digestive system comprises of alimentary canal and associated disgestive
glands.
Mouth ? Intake of whole food
?
Teeth ? Chewing/grinding of food.
?
Tongue ? Rolling of food
? +
Tasting of food
+
Swallowing / pushing down of the food
Salivary Glands ? Secrete Saliva + Mucus.
? Starch
----- - ?
Salivary
amylase
[Saliva]
Sugar
Oesophagus ? Taking food from mouth to stomach by
? Peristaltic movements
[contraction and expansion of muscles of the oesophagus]
Stomach ? Gastric glands secrete Gastric juice
Page 5


AK
50 X – Science
CHAPTER – 6
LIFE PROCESSES
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.
Examples :
Kinds of nutrition in which in organic
materials like CO
2
, water etc are utilized to
prepare organic food by the process of
photosyntheses
Eg. Green Plants
Kinds of nutrition in which in organisms do
not possess the ability to synthesize their
own food. They depend on autotrophs for
their food supply directly or indirectly.
eg. Animals, Fungi
AK
51 X – Science
Autotrophic Nutrition :
The organisms which carry out autotrophic nutrition are called autotrophs (green
plants)
Autotrophic nutrition is fulfilled by the process by which autotrophs take in CO
2
and
H
2
O and convert these into carlohydrates in the presence of chlorophyll, sunlight is
called PHOTOSYNTHESIS
Equation :
Raw Materials for Photosynthesis :
q Sunlight
q Chlorophyl ? Sunlight absorbed by chlorophyll
q CO
2
? enters through Stomata, and Oxygen (O
2
) is released as by product
through stomata on leaf.
q Water ? water + dissolved minerals like Nitrogen phosphorous etc are taken
up by the roots from the soil.
Site of Photosynthesis :
Chloroplast in the leaf. Chloroplast contain chlorophyll. (green pigment)
Main Events of Photosynthesis :
q Absorption of light energy by chlorophyll
q Conversion of light energy into chemical energy + splitting (breaking) of water
into hydrogen and oxygen.
q Reduction of CO
2
to carbohydrates.
STOMATA : Tiny pores present on the surface of the leaves
FUNCTIONS :
(i) Exchange of gases O
2
/CO
2
(ii) Loses large amount of water [water vapour] during transpiration.
AK
52 X – Science
How do organisms obtain their food
Unicellular / single celled organism : food is taken up through entire surface.
Example : (i) Amoeba. (ii) Paramaecium
AK
53 X – Science
NUTRITION IN HUMAN BEINGS
The human digestive system comprises of alimentary canal and associated disgestive
glands.
Mouth ? Intake of whole food
?
Teeth ? Chewing/grinding of food.
?
Tongue ? Rolling of food
? +
Tasting of food
+
Swallowing / pushing down of the food
Salivary Glands ? Secrete Saliva + Mucus.
? Starch
----- - ?
Salivary
amylase
[Saliva]
Sugar
Oesophagus ? Taking food from mouth to stomach by
? Peristaltic movements
[contraction and expansion of muscles of the oesophagus]
Stomach ? Gastric glands secrete Gastric juice
AK
54 X – Science
Small Intestinal ?
Small Intestine ? Villi
-- ?
helps in absorption of food into the blood.
[finger like projections]
small intestine ? Receives
secretion from
Emulsification : The process of breakdown of large fat
globules into smaller fat globules by bile juice.
Large intestine ? Absorb excess of water.
? The rest of the material is removed from the body via the
anus. (Egestion)