NCERT Solutions Class 10th Science Chapter – 5 Life Processes Notes

September 7, 2023

NCERT Solutions Class 10th Science Chapter – 5 Life Processes

Textbook	NCERT
Class	10^th
Subject	Science
Chapter	5^th
Chapter Name	Life Processes
Category	Class 10th Science
Medium	English
Source	Last Doubt

NCERT Solutions Class 10th Science Chapter – 5 Life Processes Notes In This Chapter we will learn about Life Processes, Respiration in Animals, Nutrition, Transportation in plants, Excretion, Modes of Nutrition, Autotrophic Nutrition, How do organisms obtain their food, Small Intestine, Large Intestine and more such things for more knowledge about this Chapters read their Notes.

NCERT Solutions Class 10th Science Chapter – 5 Life Processes

Chapter – 5

Life Processes

Notes

Life processes – All the processes like respiration, digestion, which together keep the living organisms alive and perform the job of body maintenance are called life processes.

All living things perform certain life processes like growth, excretion, respiration, circulation, Digestion etc.

Life processes

• Digestion
• Respiration
• Circulation
• Excretion

Nutrition – (The whole process by which an organism obtains its food)

Nutrition in Plants
↓
Plants are autotrophs.
↓
Can make their own food.

Nutrition in Animals
↓
Animals are hetrotrophs.
↓
Depends on plants or other animals for their food

Modes of Nutrition

Autrotrophic	Hetrotrophic
Kind of nutrition in which inorganic materials like CO_₂,	Kind of nutrition in which organisms do not possess
water etc. are utilized to prepare organic food by the process of photosynthesis.	the ability to synthesize their own food. They depend on autotrophs for their food supply directly or indirectly.
E.g: Green plants	E.g: Animals, fungi.

Autotrophic Nutrition

The organisms which carry out autotrophic nutrition are called autotrophs (green plants).

Autotrophs Use → Simple inorganic material Convert into → Complex high energy molecules (Carbohydrates)

Autotrophic nutrition is the process by which autotrophs take in CO, and H₂O and convert these into carbohydrates in the presence of chlorophyll, sunlight is called Photosynthesis.

Equations – 6CO_₂+ 12H_₂O Sunlight / Chlorophyll → C₆H_₁₂O₆ + 60_₂+ 6H_₂O

Raw Materials for Photosynthesis

Chlorophyll → Sunlight absorbed by chlorophyll

CO₂ → Enters through stomata and oxygen (O₂) is released as by product through stomata on leaf.

Water → Water + dissolved minerals like nitrogen, phosphorus etc. are taken up by the roots of the soil.

Site of Photosynthesis – Chloroplast in the leaf, chloroplast contain chlorophyll (green pigment).

Main Events of Photosynthesis

• Absorption of light energy by chlorophyll

• Conversion of light energy into chemical energy + splitting (breaking) of water into hydrogen and oxygen

• Reduction of CO₂ to carbohydrates

Hetrotrophic Nutrition

Holozoic	Saprophytic	Parasitic
Animals take in solid food and breakdown inside the body.	Organisms feed on dead, decaying matter.	Parasites live inside or outside other organism (host) and derive nutrition from it.
E.g., Amoeba, animals.	E.g., Fungi.	E.g., Cuscuta (plant parasites), Ticks leech etc

Steps of Nutrition – (In Heterotrophs)

Ingestion	Digestion	Absorption	Assimilation	Egestion
(Intake of food)	(Breakdown of complex material into simple ones)	(Movement of digested food)	(utilization of food)	(Removal of waste products)

Nutrition in Human Beings

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

Gastric Juice

• Pepsin – (Enzyme that breaks down proteins)

• HCL – (Makes medium acidic)

• Mucus – (Protects inner lining of the stomach)

Small Intestine

(a) Intestinal enzyme

↓ convert

Carbohydrate → (Glucose)

Fats → (Fatty acid + Glycerol)

Proteins → (Amino acids)

(b) Villi (finger like projections) → Helps in absorption of digested food into the blood

Large Intestine

→ Absorb excess of water.

→ The rest of the material is removed from the body via the anus.

RESPIRATION

(i) Gaseous exchange – Intake of oxygen from the atmosphere and release of CO₂→ Breathing

(ii) Breakdown of simple food in order to release energy inside the cell → Cellular respiration

Respiration

Aerobic	Anaerobic
• 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
↓
Nasal Passage
↓
Nasal Cavity
↓
Pharynx
↓
Larynx
↓
Trachea
↓
Bronchi
↓
Bronchioles
↓
Alveoli
↓
Blood capillaries

Lungs

Bronchi
↓
Bronchioles
↓
Alveoli
↓
Blood capillaries

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 alveolus, blood and tissues

(i) Air (rich in O_₂) → Blood → Binds with haemoglobin in RBC → O₂ is released in (in alveolus) (through blood vessels) tissues

(ii) CO₂ → Released in blood→ Dissolved in blood→ Blood vessels→ Released in alveolar sac → Sent out through nostrils (from tissue)

Terrestrial – 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 – Human beings like other multicellular organism need regular supply of food, oxygen etc. This function is performed by circulatory system.

Blood – (A fluid connective tissue)

Granular component (Blood corpuscles)

R.B.C

• Carries gas (O₂, CO₂)
• Contain Hb impart red colour to the blood

Blood Platelets

• Helps in blood clotting

W.B.C

• Provide body by engulfing the germs & producing antibodies

Liquid Component (Plasma)

A yellow colour fluid contain 90% water & 10% organic substances like – plasma, proteins viz. albumin, globulin, inorganic – mineral ions.

Lymph – A yellowish fluid escapes from the blood capillaries into the intercellular spaces contain less proteins than blood. Lymph flows from the tissues to the heart assisting in transportation and destroying germs.

Blood Vessels

Arteries	Veins
1. Carry oxygenated blood from heart to body parts except pulmonary artery.	1. Carry deoxygenated blood from body parts to heart except pulmonary vein.
2. Also called distributing vessel.	2. Also called collecting vessel.
3. Thick and elastic.	3. Thin and less elastic.
4. Deep Seated	4. Superficial as compared to arteries

Transportation in plant

There are two main conducting Pathways in a plant

Xylem	Phloem
1. Carries water & minerals from the roots to other parts of the plant	1. Carries product of photosynthesis from leaves to the other parts of the plant.
2. No energy is used.	2. Energy is used from ATP.

Transpiration is the process of loss of water as vapour from aerial parts of the plant.

Function
(a) Absorption and upward movement of water and minerals by creating Osmotic pressure pull.
(b) Helps in temperature regulation in plant.
Transport of food from leaves (food factory) to different part of the plant is called Translocation.

EXCRETORY SYSTEM IN HUMAN

Excretory/urinary system consists of

(1) The kidneys	The excretory organ
(2) The ureters	The ducts which drain out urine from the kidneys
(3) The urinary bladder	The urinary reservoir
(4) The urethra	The channel to the exterior

The human excretory system

EXCRETION

1. The metabolic activities in the body generates many kinds of wastes including nitrogenous wastes which are harmful for the body and hence needed to be removed. Excretion is a process by which these wastes are removed from our body.

Material excretion

• Nitrogenous wastes
• Excess of water
• Gases
• Salts

Nitrogenous wastes

• Urea
• Uric Acid
• Urine

Excess of water

• Sweat
• Urine

2. Unicellular organisms remove these wastes by simple diffusion.

Human Excretory System

1. It maintains water equilibrium, pH equilibrium, ionic equilibrium of the blood and osmotic equilibrium.
2. It helps to excrete out waste product urea in the dissolved form from the blood.
3. It excretes poisoneous substance like drugs, toxins etc. from the body.
4. It regulates blood pressure by controlling The fluid balance in the body.

Formation of Urine

1. Each kidney contains many filtration units called as nephrons.

2. Nephrons are made up of a cluster of thin walled capillaries called glomerulus which is associated with a cup like structure called as Bowman’s capsule and the long tube which terminates through this capsule.

3. The renal artery brings oxygenated blood to the kidneys along with the nitrogenous wastes like urea and uric acid and many other substances.

4. The blood gets filtered through the glomerulus and this filtrate enters the tubular part of nephron.

5. As this filtrate moves down the tubular part, glucose, amino acids, salts and excess of water gets selectively reabsorbed by the blood vessels surrounding these tubules.

6. The amount of water reabsorbed depends upon
How much excess of water is there in the body and,
How much nitrogenous wastes need to be excreted out.

7. So the fluid now flowing in the tubular part is urine which gets collected in collecting ducts of nephrons.

8. These collecting ducts together leave the kidney at a common point by forming the ureter.

9. Each ureter drains the urine in the urinary bladder where it is stored until the pressure of expanded bladder leads to an urge to pass it out through urethra.

10. This bladder is a muscular structure which is under nervous control.

11. 180 litres of filtrate is formed daily but only 2 litres is excreted out as urine so the rest is reabsorbed in the body.

The urine formation involves three steps

1. Glomerular filtration – Nitrogenous wastes, glucose water, amino acid filter from the blood into Bowman Capsule of the nephron.

2. Tubular reabsorption – Now, useful substances from the filtrate are reabsorbed back by capillaries surrounding the nephron.

3. Secretion – Urea, extra water and salts are secreted into the tubule which open up into the collecting duct & then into the ureter.

Artificial Kidney

Hemodialysis – The process of purifying blood by an artificial kidney. It is meant for kidney failure patients.

Excretion in Plants

Plants use different strategies for excretion of different products

• Oxygen and carbon dioxide is diffused through stomata.
• Excess water is removed by transpiration.
• Plants can even loose some of their old parts like old leaves and bark of tree.
• Other waste products like raisins and gums especially in old xylem cells which can also be lost by plants.
• Plants also secrete some waste substances into the soil around them.

NCERT Solution Class 10th Science All Chapters Notes

Chapter 1 – Chemical Reactions and Equations

Chapter 2 – Acids, Bases, and Salts

Chapter 3 – Metals and Non-Metals

Chapter 4 – Carbon and Its Compounds

Chapter 5 – Life Processes

Chapter 6 – Control and Coordination

Chapter 7 – How Do Organisms Reproduce

Chapter 8 – Heredity

Chapter 9 – Light reflection and refraction

Chapter 10 – Human eye and colorful world

Chapter 11 – Electricity