Biology for RRB Exams

Cell Biology

Key Facts

  • Cell: Structural and functional unit of life
  • Discovery: Robert Hooke (1665)
  • Powerhouse of Cell: Mitochondria
  • Suicide Bag: Lysosome
  • Protein Factory: Ribosome
  • Kitchen of Cell: Chloroplast (in plants)

Human Body Systems

Circulatory System

  • Heart: 4 chambers (2 Auricles, 2 Ventricles)
  • Blood Groups: Discovered by Karl Landsteiner
  • Universal Donor: O-
  • Universal Recipient: AB+
  • RBC Lifespan: 120 days

Digestive System

  • Saliva: Contains enzyme Ptyalin (Amylase)
  • Stomach: Secretes HCl (pH ~1.5-2.0)
  • Liver: Largest gland, secretes Bile
  • Small Intestine: Complete digestion and absorption

Nervous System

  • Neuron: Functional unit of nervous system
  • Cerebrum: Largest part of brain (Intelligence, memory)
  • Cerebellum: Balances body posture
  • Medulla Oblongata: Controls involuntary actions (heartbeat, breathing)

Vitamins & Deficiency Diseases

Vitamin Chemical Name Deficiency Disease
Vit A Retinol Night Blindness
Vit B1 Thiamine Beri-Beri
Vit C Ascorbic Acid Scurvy
Vit D Calciferol Rickets
Vit E Tocopherol Sterility
Vit K Phylloquinone Non-clotting of blood

Common Diseases

Pathogens

  • Viral: Common Cold, Dengue, AIDS, Polio, Rabies, COVID-19
  • Bacterial: Typhoid, Tuberculosis (TB), Cholera, Tetanus, Plague
  • Protozoan: Malaria (Plasmodium), Amoebic Dysentery, Kala-azar
  • Fungal: Ringworm, Athlete's Foot

Test Your Knowledge

30 random questions • 1 minute per question