Life Processes Lecture Notes

Jul 18, 2024

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Life Processes Lecture Notes

Introduction

  • Presenter: рдкреНрд░рд╢рд╛рдВрдд рднреИрдпрд╛
  • Importance: Comprehensive session on the Life Processes chapter. Essential for board exams.
  • Structure: In-depth exploration in the next 2 hours. Complete understanding promised.
  • Special Note: First-time biology lecture streamed on YouTube.

Key Topics in Life Processes

  1. Nutrition
  2. Respiration
  3. Transportation
  4. Excretion

Nutrition

Definition:

  • Life Processes: Essential functions performed by living organisms to maintain life.
  • Nutrition: Process by which living organisms obtain and utilize food.

Importance of Nutrition

  1. Provides energy.
  2. Ensures growth and development.
  3. Facilitates repair of damaged tissues.

Types of Nutrition

  1. Autotrophic
    • Photosynthetic Autotrophic Nutrition: e.g., Plants using photosynthesis.
    • Chemosynthetic Autotrophic Nutrition: e.g., Sulfur bacteria using chemicals to produce energy.
  2. Heterotrophic
    • Holozoic: Involves ingestion and digestion of complex organic materials. E.g., Humans, animals.
    • Saprotrophic: Involves feeding on dead and decaying organic matter. E.g., Fungi, bacteria.
    • Parasitic: Involves feeding on living organisms. E.g., Leech, lice, Cuscuta plant.

Photosynthesis - In-depth

  • Ingredients required: CO2, Water, Light, Chlorophyll

  • Photosynthesis Reaction:

    6CO2 + 6H2O + Light тЖТ C6H12O6 + 6O2

  • Stomata: Tiny pores on leaves for gas exchange.

  • Desert Plants: Adaptations to store sunlight as chemical energy, perform photosynthesis during cooler periods.

Respiration

Definition

  • Process by which living organisms obtain energy (ATP) from the breakdown of glucose in the presence of oxygen.

Types of Respiration

  1. Aerobic Respiration: Occurs in the presence of oxygen. Produces CO2, water, and ATP.
  2. Anaerobic Respiration: Occurs in the absence or low presence of oxygen. Produces less energy, lactic acid, or ethanol.
    • In muscles during vigorous exercise (lactic acid formed).
    • In yeast (ethanol and CO2 formed).

Human Respiratory System

  • Organs involved: Nasal Cavity, Pharynx, Larynx, Trachea, Bronchi, Lungs (Alveoli)
  • Alveoli: Site of gas exchange
  • Hemoglobin: Helps in the exchange of O2 and CO2 between alveoli and blood.

Transportation

Circulatory System

  1. Blood: Composed of plasma and blood corpuscles (RBCs, WBCs, Platelets).
    • Functions: Transportation of O2, nutrients, waste products, hormones, and regulation of body temperature.
  2. Blood Vessels: Arteries, Veins, Capillaries
    • Arteries: Carry blood away from the heart. Usually oxygenated (except pulmonary artery).
    • Veins: Carry blood towards the heart. Usually deoxygenated (except pulmonary veins).
    • Capillaries: Allow exchange of materials between blood and tissues.
  3. Heart: Pumps blood through a double circulation system (Systemic and Pulmonary circuits).
    • Structure: Four chambers (Left & Right Atrium, Left & Right Ventricle)
    • Function: Pumps oxygenated blood to the body and deoxygenated blood to the lungs.

Lymphatic System

  • Components: Lymph, Lymph vessels, Lymph nodes
  • Functions: Fluid balance, transport of fats, immune system support

Transportation in Plants

  1. Xylem: Transports water and minerals from roots to leaves.
  2. Phloem: Transports food from leaves to other parts of the plant.
  3. Translocation: Movement of food through phloem.

Excretion

Definition

  • The process by which metabolic waste products are eliminated from an organism's body.

Human Excretory System

  • Components: Kidneys, Ureters, Urinary Bladder, Urethra
  • Nephron: Functional unit of the kidney, responsible for purification of blood.
    • Steps in Nephron Functioning:
      1. Glomerular Filtration: Filtration of blood in Bowman's capsule.
      2. Selective Reabsorption: Absorption of useful substances back into the blood in the tubule.
      3. Tubular Secretion: Secretion of additional wastes into the tubule.
  • Dialysis: Artificial method to remove wastes and excess water from the blood when kidneys fail.

Excretion in Plants

  • Strategies: Transpiration for excess water, diffusion through stomata for gases.
  • Storage of waste products in vacuoles, expulsion in the form of latex or gums.

Conclusion

  • Key learnings: Detailed understanding of life processes covering all essential biological functions.
  • Encouragement to review notes, practice questions, and ensure a strong grasp on the material.