Life Processes

• Nutrition


  The process by which living beings obtain food and utilize it for obtaining energy for different activities
• The alimentary canal in human beings is a long continuous tube beginning at the mouth and ending at the anus, measuring 8-10 meters in length
• Heterotrophic nutrition


  Organisms derive energy directly or indirectly from autotrophs or other sources; can be saprophytic, parasitic, or holozoic
• Holozoic nutrition

  Organisms obtain complex organic matter by consuming other organisms through ingestion
• Life processes


  The unique dynamic systems or processes essential for sustaining life
• Types of nutrition

  • Autotrophic nutrition
  • Heterotrophic nutrition
• Saprophytic nutrition


  Organisms derive nutrients from dead and decaying organic matter
• Autotrophic nutrition


  Organisms manufacture their own food from simple inorganic raw materials like carbon dioxide, water, and mineral salts through photosynthesis
• Photosynthesis


  The process by which green plants produce carbohydrates using sunlight, CO2, and water; involves conversion of light energy into chemical energy
• Photosynthesis occurs in cells with chloroplasts, which are green-colored cell organelles
• Important life processes

  • Nutrition
  • Respiration
  • Transportation
  • Excretion
• Parasitic nutrition


  Organisms derive nutrients from other organisms; can be endoparasites or ectoparasites
• Oral Cavity (Buccal Cavity)


  Foremost part of the alimentary canal which helps in ingestion, contains teeth, tongue, and salivary glands
• Tongue in the oral cavity

  Mixes food thoroughly with saliva and aids in tasting, mixing, and swallowing of food
• Digestive canal


  Each part plays a specific role in the process of nutrition
• Stomach


  1. shaped, widest part of the alimentary canal, contains gastric glands releasing gastric juices with components like pepsin, HCl, and mucus
• Roots of plants respire with the help of root hairs, stems and roots have breathing pores called lenticels, leaves have stomata for gas exchange
• Small intestine


  Site of complete digestion and absorption of food, contains villi for absorption of digested soluble food products
• Nasal Chamber


  Warms, moistens, and filters air, checks entry of dust particles
• Teeth in the oral cavity

  Work together to break larger food particles into smaller pieces of the same texture
• The anus measures 8-10 metres in length
• In plants, all parts respire separately without a specific organ for gas exchange, gases move by diffusion
• Nostrils

  Used to draw air into the nasal cavity
• Pancreas


  Large gland secreting pancreatic juice with digestive enzymes like trypsin, lipase, and amylase
• Peristalsis

  Rhythmic contraction and relaxation of muscles in the alimentary canal to push food ahead
• Oesophagus


  Food passes into the stomach through peristalsis
• Oral Cavity (Buccal Cavity)


  Foremost part which opens by mouth to the outside, helps in ingestion, contains teeth, tongue, and salivary glands
• Large intestine

  Absorbs water and salts from undigested food, passes dry contents (faeces) to rectum for elimination through the anus
• Liver


  Largest gland secreting bile juice for emulsification of fats and making the medium alkaline for pancreatic enzymes
• Respiratory organs in animals

  • Nostrils
  • Nasal Chamber
  • Pharynx
• Pharynx


  Common passage for digestive and respiratory tracts, covers glottis while swallowing food
• Trachea

  Contains incomplete C-shaped rings to prevent collapse. Divides into bronchi upon entering the thoracic cavity
• Air passage


  The air gets warmed, moistened, and filtered by the hair lining the passage. This region checks the entry of dust particles
• Capillaries


  Very narrow blood vessels forming a network inside body organs. Help in exchange of material between blood and surrounding cells
• Blood


  Liquid connective tissue consisting of plasma and cellular parts. Plasma constitutes about 55% of blood and contains glucose, amino acids, hormones, and proteins. Cellular part includes RBCs, WBCs, and blood platelets
• Lungs


  Two organs in the thoracic cavity separated from the abdominal cavity by the diaphragm. Aid in the process of breathing
• Veins

  Blood vessels carrying blood from different organs to the heart. Thin-walled and provided with valves to prevent backflow of blood
• Alveoli


  Clusters of balloons or grape-like structures where bronchioles terminate. Provide a large surface area for exchange of gases due to thin walls and extensive network of blood vessels
• Larynx


  Voice box located at the junction of pharynx and trachea. Vocal chords vibrate to produce sound when air passes over them
• Transport System in Human Beings is carried out by the circulatory system consisting of tubes, a pumping heart, and circulating fluids blood and lymph