Study Material and Notes of Ch 6 Life Process Part-II Class 10th Science
Topics in the Chapter
• Respiration in Human Beings
→ Breakdown of Glucose by Various Pathways
→ Types of Respiration
→ Human Respiratory System
→ Mechanism of Breathing
• Respiration in plants
• Transportation in Human Beings
→ Circulatory system in human beings
• Blood circulation in human body
• Blood
→ Lymph
→ Types of Blood Vessels
→ Exchange of gases between alveoli, blood and tissues
• Transportation in Plants
→ Transpiration and its Functions
• Excretion System in Human Beings
→ Excretory wastes
→ Three steps of Urine formation
→ Formation of Urine in Human Beings
→ Functions of Nephron
→ Artificial Kidney
• Excretion in Plants
Respiration in Human Beings
→ Respiration involves:
(i) Gaseous exchange (Breathing) : Intake of oxygen from the atmosphere and release of CO2.
(ii) Cellular respiration: Breakdown of simple food in order to release energy inside the cell.
• Breakdown of Glucose by Various Pathways
→ The first step is the break-down of glucose (a six-carbon molecule) into a three-carbon molecule called pyruvate which takes place in the cytoplasm.
→ The pyruvate may be converted into ethanol and carbon dioxide which takes place in yeast during fermentation. Since this process takes place in the absence of air (oxygen), it is called anaerobic respiration.
→ The pyruvate is broken down into three-carbon pyruvate molecule in the presence of oxygen to give three molecules of carbon dioxide and water. This process takes place in mitochondria. Since this process takes place in the presence of air (oxygen), it is called aerobic respiration.
→ The pyruvate is converted into lactic acid when there is a lack of oxygen in our muscle cells, which is also a three-carbon molecule. This build-up of lactic acid in our muscles during sudden activity causes cramps.
The whole process of break down of glucose is shown below:
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→ The energy released during cellular respiration is immediately used to synthesise a molecule called ATP which is used to fuel all other activities in the cell. In these processes, ATP is broken down giving rise to a fixed amount of energy which can drive the endothermic reactions taking place in the cell.
→ The rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms because the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air.
• Types of Respiration
• Human Respiratory System
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Passage of air through the respiratory system:
→ Nostril: Air is taken into the body.
→ Nasal Passage: It is a channel for airflow through the nose.
→ Nasal Cavity: It is lined with hairs and mucus membrane. It warms, moisturize, and filter air before it reaches the lungs.
→ Pharynx: It contains rings of cartilage which ensure that the air-passage does not collapse.
→ Larynx: It houses the vocal cords and manipulates pitch and volume, which is essential for phonation. It is also known as voice box.
→ Trachea: Pharynx splits into trachea and esophagus. It connects the larynx (or voice box) to the bronchi of the lungs. It provides air flow to and from the lungs for respiration.
→ Bronchi: They are the main passageway into the lungs. They are the extensions of the windpipe that shuttle air to and from the lungs. The oxygen goes to the lungs and carbon dioxide leave the lungs through them.
→ Bronchioles: Bronchi get smaller when they reaches closer to lungs tissues and are called Bronchioles. They are the passageways by which air passes through the nose or mouth to the alveoli of the lungs
→ Alveoli: They are smaller tubes which finally terminate in balloon-like structures which are called alveoli. They allow oxygen and carbon dioxide to move between the lungs and bloodstream.
→ Blood capillaries: They are the sites of the transfer of oxygen and other nutrients from the bloodstream to other tissues in the body. They also collect carbon dioxide and waste materials and return it to the veins.
• Mechanism of Breathing
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• Exchange of gases between alveoli, blood and tissues
(i) Air (rich in O2) reaches blood which combines with haemoglobin in RBC and O2 is released in
alveoli tissues (through blood vessels).
(ii) CO2 is released in blood and dissolved into it and carried by blood vessels. The carbon dioxide is released in alveolar sac which is sent out through nostrils.
→ Terrestial organisms: Use atmospheric oxygen for respiration.
→ Aquatic organisms: Use dissolved oxygen for respiration.
Respiration in plants
Respiration in plants is simpler than the respiration in animals. Gaseous exchange occur through :
(a) Stomata in leaves
(b) Lenticels in stems
(c) General surface of the root
• Transportation in Human Beings
Human beings like other multicellular organism need regular supply of food, oxygen etc. This function is performed by circulatory system.
→ Circulatory system in human beings
• Blood circulation in human body
• Blood
→ Lymph
→ Types of Blood Vessels
• Transportation in Plants
→ Transpiration and its Functions
• Excretion System in Human Beings
→ Excretory wastes
→ Formation of Urine in Human Beings
→ Structure of Nephron
→ Functions of Nephron
→ Artificial Kidney
• Excretion in Plants
• Respiration in Human Beings
→ Breakdown of Glucose by Various Pathways
→ Types of Respiration
→ Human Respiratory System
→ Mechanism of Breathing
• Respiration in plants
• Transportation in Human Beings
→ Circulatory system in human beings
• Blood circulation in human body
• Blood
→ Lymph
→ Types of Blood Vessels
→ Exchange of gases between alveoli, blood and tissues
• Transportation in Plants
→ Transpiration and its Functions
• Excretion System in Human Beings
→ Excretory wastes
→ Three steps of Urine formation
→ Formation of Urine in Human Beings
→ Functions of Nephron
→ Artificial Kidney
• Excretion in Plants
Respiration in Human Beings
→ Respiration involves:
(i) Gaseous exchange (Breathing) : Intake of oxygen from the atmosphere and release of CO2.
(ii) Cellular respiration: Breakdown of simple food in order to release energy inside the cell.
• Breakdown of Glucose by Various Pathways
→ The first step is the break-down of glucose (a six-carbon molecule) into a three-carbon molecule called pyruvate which takes place in the cytoplasm.
→ The pyruvate may be converted into ethanol and carbon dioxide which takes place in yeast during fermentation. Since this process takes place in the absence of air (oxygen), it is called anaerobic respiration.
→ The pyruvate is broken down into three-carbon pyruvate molecule in the presence of oxygen to give three molecules of carbon dioxide and water. This process takes place in mitochondria. Since this process takes place in the presence of air (oxygen), it is called aerobic respiration.
→ The pyruvate is converted into lactic acid when there is a lack of oxygen in our muscle cells, which is also a three-carbon molecule. This build-up of lactic acid in our muscles during sudden activity causes cramps.
The whole process of break down of glucose is shown below:
→ The energy released during cellular respiration is immediately used to synthesise a molecule called ATP which is used to fuel all other activities in the cell. In these processes, ATP is broken down giving rise to a fixed amount of energy which can drive the endothermic reactions taking place in the cell.
→ The rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms because the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air.
• Types of Respiration
Aerobic Respiration | Anaerobic Respiration |
| Takes place in the presence of oxygen. | Takes place in the absence of oxygen. |
| Occurs in mitochondria. | Occurs in cytoplasm. |
| End products are CO2 and H2O. | End products are alcohol or lactic acid. |
| More amount of energy is released. | Less amount of energy is released. |
• Human Respiratory System
Passage of air through the respiratory system:
→ Nostril: Air is taken into the body.
→ Nasal Passage: It is a channel for airflow through the nose.
→ Nasal Cavity: It is lined with hairs and mucus membrane. It warms, moisturize, and filter air before it reaches the lungs.
→ Pharynx: It contains rings of cartilage which ensure that the air-passage does not collapse.
→ Larynx: It houses the vocal cords and manipulates pitch and volume, which is essential for phonation. It is also known as voice box.
→ Trachea: Pharynx splits into trachea and esophagus. It connects the larynx (or voice box) to the bronchi of the lungs. It provides air flow to and from the lungs for respiration.
→ Bronchi: They are the main passageway into the lungs. They are the extensions of the windpipe that shuttle air to and from the lungs. The oxygen goes to the lungs and carbon dioxide leave the lungs through them.
→ Bronchioles: Bronchi get smaller when they reaches closer to lungs tissues and are called Bronchioles. They are the passageways by which air passes through the nose or mouth to the alveoli of the lungs
→ Alveoli: They are smaller tubes which finally terminate in balloon-like structures which are called alveoli. They allow oxygen and carbon dioxide to move between the lungs and bloodstream.
→ Blood capillaries: They are the sites of the transfer of oxygen and other nutrients from the bloodstream to other tissues in the body. They also collect carbon dioxide and waste materials and return it to the veins.
• Mechanism of Breathing
Inhalation | Exhalation |
| During inhalation the thoracic cavity (chest cavity) expands. | Thoracic cavity contracts. |
| Ribs lift up. | Ribs move downwards. |
| Diaphragm become flat in shape. | Diaphragm becomes dome shaped. |
| Volume of lungs increases and air enters the lungs. | Volume of lungs decreases and air exits from the lungs. |
• Exchange of gases between alveoli, blood and tissues
(i) Air (rich in O2) reaches blood which combines with haemoglobin in RBC and O2 is released in
alveoli tissues (through blood vessels).
(ii) CO2 is released in blood and dissolved into it and carried by blood vessels. The carbon dioxide is released in alveolar sac which is sent out through nostrils.
→ Terrestial organisms: Use atmospheric oxygen for respiration.
→ Aquatic organisms: Use dissolved oxygen for respiration.
Respiration in plants
Respiration in plants is simpler than the respiration in animals. Gaseous exchange occur through :
(a) Stomata in leaves
(b) Lenticels in stems
(c) General surface of the root
• Transportation in Human Beings
Human beings like other multicellular organism need regular supply of food, oxygen etc. This function is performed by circulatory system.
→ Circulatory system in human beings
• Blood circulation in human body
• Blood
→ Lymph
→ Types of Blood Vessels
• Transportation in Plants
→ Transpiration and its Functions
• Excretion System in Human Beings
→ Excretory wastes
→ Formation of Urine in Human Beings
→ Structure of Nephron
→ Functions of Nephron
→ Artificial Kidney
• Excretion in Plants