Topics to be learn

• Introduction
• Modes of Nutrition
• Autotrophic Nutrition
• Stomata
• Heterotrophic Nutrition
• Nutrition
• Nutrition in Human Beings
• Respiration in Human Beings
• Respiration in plants
• Transportation in Human Beings
• Blood circulation in human body
• Blood
• Transportation in Plants
• Excretion System in Human Beings
• Excretion in PlantsIntroduction:
  • Living things carry out life processes like growth, excretion, respiration, and circulation.
  • These processes collectively maintain the organism's life and are known as life processes.

Modes of Nutrition:

  • Nutrition in Plants
    • Plants are autotrophs.
    • They produce their own food through photosynthesis.
    • They do not consume other organisms for food.   

Nutrition in Animals:

  • Animals are heterotrophs.
  • They depend on plants or other organisms for their nutrition.
Autotrophic Nutrition:
  • Utilizes inorganic materials like CO2 and water for photosynthesis, mainly seen in green plants.
  • Organisms performing autotrophic nutrition are termed autotrophs (e.g., green plants).
  • Autotrophs convert simple inorganic materials into complex carbohydrates using chlorophyll and sunlight through photosynthesis.
  • Equation for Photosynthesis: 6CO2​+6H2​Ochlorophyllsunlight​C6​H12​O6​+6O2​

Raw materials for photosynthesis:

  • Sunlight: Absorbed by chlorophyll.
  • Chlorophyll: Pigment in chloroplasts.
  • CO2: Enters through stomata, releasing O2 as a by-product.
  • Water: Absorbed by roots along with dissolved minerals.

Site of Photosynthesis:

  • Photosynthesis occurs in cells containing chloroplasts with chlorophyll.


 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.

Stomata:

  • Tiny pores on the surface of leaves.


Functions of stomata:

  • Exchange of gases: O2/CO2.
  • Loss of water (water vapor) during transpiration.

Heterotrophic Nutrition:

  • Type of nutrition where organisms cannot synthesize their own food. They rely on autotrophs for food directly or indirectly.
    • Example: Animals, fungi.

Types of Heterotrophic Nutrition:

  1. Holozoic Nutrition:

    • Animals ingest solid food and digest it internally.
    • Example: Amoeba, animals.

  2. Saprophytic Nutrition:

    • Organisms consume dead, decaying matter for nutrition.
    • Example: Fungi.

  3. Parasitic Nutrition:

    • Parasites live in or on other organisms (hosts) and obtain nutrition from them.
    • Example: Cuscuta (plant parasites), Ticks, etc.
How Organisms Obtain Their Food:
  • Unicellular/Single-Celled Organisms:
    • Food is absorbed through the entire surface.
    • Example: Amoeba, Paramecium.

     

Process of Food Intake by Amoeba:

  • Amoeba extends its pseudopodia (finger-like projections) to engulf food particles.

 

Process of Intake of Food by Paramecium:

  • Cilia (tiny hair-like structures) present all over the body help in food intake.
  • Food is taken in at a specific spot.

Nutrition:

  • Different organisms utilize various nutritional processes depending on the source of carbon from which food is obtained.


Nutrition in Human Beings:

  • Alimentary Canal: A long tube from mouth to anus with specialized regions performing different functions.

Human Digestive System:

 

  1. Mouth:

    • Intake of whole food.

  2. Teeth:

    • Chewing/grinding of food.

  3. Tongue:

    • Rolling of food + Tasting + Swallowing.

  4. Salivary Glands:

    • Secrete saliva + Mucus.
    • Saliva contains salivary amylase, converting starch to glucose.

  5. Oesophagus:

    • Transports food from mouth to stomach via peristaltic movements.

  6. Stomach:

    • Gastric glands secrete gastric juice.
     

  7. Small Intestine:

    • Site of complete digestion of carbohydrates, proteins, and fats.
    • Intestinal enzymes convert carbohydrates to glucose, fats to fatty acids + glycerol, and proteins to amino acids.
    • Villi aid in food absorption into the blood.
    • Receives secretions from liver and pancreas.
      • Pancreatic juice contains enzymes like trypsin for protein digestion and lipase for fat breakdown.
      • Bile salts from the liver emulsify fats, aiding enzyme action.

  8. Large Intestine:

    • Absorbs excess water.
    • Eliminates remaining material via the anus.
    Respiration in Human Beings

  • Respiration involves:

    • Gaseous exchange (Breathing):
      • Intake of oxygen from the atmosphere and release of CO2.
    • Cellular respiration:
      • Breakdown of simple food to release energy inside the cell.

  • Breakdown of Glucose by Various Pathways:

    • Glucose (a six-carbon molecule) breaks down into pyruvate.
      • Takes place in the cytoplasm.
    • Pyruvate may convert into:
      • Ethanol and carbon dioxide in yeast during fermentation (anaerobic respiration).
      • Three molecules of carbon dioxide and water in the presence of oxygen in mitochondria (aerobic respiration).
      • Lactic acid in muscle cells when oxygen is lacking, causing cramps.
       

  • Energy Release:

    • ATP synthesized from released energy, fuels cell activities.
      • ATP broken down to drive endothermic reactions.

  • Rate of Breathing:

    • Aquatic organisms breathe faster than terrestrial organisms due to lower dissolved oxygen.

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 intake.
  • Nasal Passage: Channel for airflow.
  • Nasal Cavity: Lined with hairs and mucus, warms, moisturizes, and filters air.
  • Pharynx: Contains cartilage rings to prevent collapse.
  • Larynx: Houses vocal cords, manipulates pitch and volume.
  • Trachea: Connects larynx to bronchi, provides airflow to and from lungs.
  • Bronchi: Main passageway into lungs, oxygen in, carbon dioxide out.
  • Bronchioles: Smaller passages leading to alveoli.
  • Alveoli: Balloon-like structures for gas exchange between lungs and bloodstream.
  • Blood capillaries: Transfer oxygen and nutrients to tissues, collect carbon dioxide and waste.

Mechanism of Breathing

Inhalation

Exhalation

Thoracic cavity expands.

Thoracic cavity contracts.

Ribs lift up.

Ribs move downwards.

Diaphragm becomes flat.

Diaphragm becomes dome-shaped.

Volume of lungs increases, air enters.

Volume of lungs decreases, air exits.

 Exchange of gases between alveoli, blood, and tissues

  • Air (rich in O2) combines with haemoglobin in RBC, O2 released in tissues.
  • CO2 released in blood, carried by blood vessels.
  • Carbon dioxide released in alveolar sac, exhaled.

Respiration in Different Organisms

  • Terrestrial organisms: Use atmospheric oxygen.
  • Aquatic organisms: Use dissolved oxygen.

Respiration in Plants

  • Gaseous exchange:
    • Occurs through: (a) Stomata in leaves (b) Lenticels in stems (c) General surface of the root
Transportation in Human Beings
  • Circulatory System:
    • Consists of: (i) Heart (pumping organ) (ii) Arteries and Veins (Blood vessels) (iii) Blood and lymph (Circulatory medium)

Circulatory System in Human Beings

 

  • Heart Function:
    • Lungs supply oxygen-rich blood to left atrium.
    • Left atrium relaxes to collect blood, contracts to transfer to left ventricle.
    • Left ventricle expands when receiving blood.
    • Blood pumped out when left ventricle muscles contract.
    • De-oxygenated blood from body to right atrium.
    • Right atrium expands to receive blood.
    • Right ventricle expands when right atrium contracts, pumping blood to lungs for oxygenation.
    • Right ventricles have thicker walls to pump blood into organs.
  • Valves: Ensure blood doesn't flow backwards when atria or ventricles contract.
Blood Circulation in Human Body
  • Double Circulation:
    • Blood travels twice through the heart in one complete body cycle.

Direction of Blood Flow through Human Heart

  • Pulmonary Circulation: Heart to lungs and back to heart.
  • Systemic Circulation: Heart to rest of the body and back to heart.
Blood
  • Solid components (Blood corpuscles):
    • RBC (Red blood cells): Carry O2 and CO2, contain Haemoglobin.
    • WBC (White blood cells): Provide body defense, produce antibodies.
    • Blood Platelets: Aid in blood clotting.
  • Liquid components (Plasma):
    • Yellow fluid, 90% water & 10% organic substances.

Blood Pressure

  • Definition: Force of blood against vessel walls.
  • Difference: Higher in arteries than veins.

Types of Blood Pressure

  • Systolic Pressure: Pressure during ventricular contraction (systole).
  • Diastolic Pressure: Pressure during ventricular relaxation (diastole).
  • Normal Levels: Systolic pressure around 120 mmHg, diastolic pressure around 80 mmHg.
  • Measurement Tool: Sphygmomanometer.

High Blood Pressure (Hypertension)

  • Cause: Constriction of arterioles, increasing blood flow resistance.
  • Risk: Artery rupture and internal bleeding.

Lymph

  • Yellowish fluid, less proteins than blood.
  • Flows from tissues to heart, aids transportation, destroys germs.
  • Carries digested fat, drains excess fluid back into blood.

Types of Blood Vessels

Arteries

Veins

Carry oxygenated blood except pulmonary artery.

Carry deoxygenated blood except pulmonary vein.

Distributing vessel.

Collecting vessel.

Thick and elastic.

Thin and less elastic.

Deep-seated.

Superficial as compared to arteries.
 
Transportation in Plants
  • Two main conducting pathways: (i) Xylem & (ii) Phloem

Xylem

Phloem

Carries water & minerals from roots.

Carries products of photosynthesis from leaves.

No energy used.

Energy from ATP used.

 

 

 

Transpiration and its Functions

  • Transpiration: Loss of water as vapor from aerial parts of the plant.
  • Functions:
    • (a) Absorption and upward movement of water and minerals by creating PULL.
    • (b) Helps in temperature regulation in plant.

Translocation: Transport of food from leaves (food factory) to different parts of the plant.

Excretion System in Human Beings
  • Components of Excretory System:
    1. Kidneys: Excretory organ
    2. Ureters: Ducts draining urine from kidneys
    3. Urinary Bladder: Urinary reservoir
    4. Urethra: Channel to the exterior
     

Excretion

  • Metabolic activities generate wastes, including nitrogenous wastes, harmful to the body, removed through excretion.
  • Unicellular organisms remove wastes by simple diffusion.

Functions of Organs involved in Excretory System

  • Nephrons:
    • Filtration units in kidneys.
    • Made up of:
      • Glomerulus: Thin-walled capillaries.
      • Bowman’s capsule: Cup-like structure.
      • Long tubule.
    • Renal Artery brings oxygenated blood, nitrogenous wastes to kidneys.
    • Blood filtered through glomerulus, filtrate enters nephron tubule.
    • Glucose, amino acids, salts, excess water selectively reabsorbed by surrounding blood vessels.
    • Amount of water reabsorbed depends on:
      • Excess water in body.
      • Nitrogenous wastes to be excreted.
    • Fluid in tubule becomes urine, collected in collecting ducts.
    • Collecting ducts form ureter, draining urine to bladder.
    • Urinary Bladder:
      • Stores urine until pressure leads to urge to pass it out through urethra.
      • Muscular structure under nervous control.
    • 180 litres of filtrate formed daily, only 2 litres excreted as urine, rest reabsorbed.
Structure of Nephron

 

  • Functions of Nephron:
    • Excretion of nitrogenous wastes.
    • Maintain water and ionic balance (osmotic regulation).

Formation of Urine in Humans

  • Glomerular Filtration:

    Nitrogenous wastes, glucose, water, amino acids filter from blood into Bowman's Capsule of nephron.

  • Tubular Reabsorption:

    Useful substances from filtrate reabsorbed by surrounding capillaries.

  • Secretion:

    Urea, extra water, salts secreted into tubule opening into collecting duct, then ureter.

 Artificial Kidney

  • Haemodialysis:
    • Purifying blood by an artificial kidney.
    • Meant for kidney failure patients.

Excretion in Plants

  • Plants use different strategies for excretion:
    • Oxygen and carbon dioxide diffused through stomata.
    • Excess water removed by transpiration.
    • Shedding of old parts like leaves and bark.
    • Waste products like resins and gums, especially in old xylem cells.
    • Some waste substances secreted into the soil.