ANIMAL NUTRITION

• Types of heterotrophs based on mode of nutrition

  • Parasitic
  • Saprophytic
  • Holozoic
• Parasitic


  An organism (parasite) living on the body or surface of another organism (host). This relationship is known as "parasitism".
• Saprophytic

  Organisms (saprophytes) obtain food from the dead and decaying matter. (Fungi, some protists, bacteria, etc.)
• Holozoic


  An organism consumes a variety of organic material which then undergoes a series of metabolic processes such as digestion, absorption, and assimilation.
• Types of heterotrophs based on food habits

  • Herbivores
  • Carnivores
  • Omnivores
  • Detritivores (decomposers)
• Herbivores


  Mostly feed on plants (deer, cow, buffalo, grasshoppers, and rabbits.)
• Carnivores


  Organism that mostly eats meat or flesh of animals. Predators and prey have a cycle known as predation. (lion, tiger, leopard, cougar, wolf, cheetah, and red fox)
• Omnivores


  Eats plants and animals. (Humans, bears, foxes, boar, skunk, turtle, and ostrich)
• Detritivores (decomposers)


  Feeds on the remains of plants, animals, and fecal matter. (bacteria, fungi, worms, and insects.)
• Digestion process

  1. Mouth - chews food and mixes it saliva

  2. Salivary glands - produces saliva containing a starch-digesting enzyme called salivary amylase

  3. Pharynx - swallows the chewed food mixed with saliva called bolus

  4. Esophagus - moves the bolus through peristalsis

  5. Stomach - mixes and churns food with gastric juices

  6. Liver - makes bile which aids in digestion and absorption of fat

  7. Pancreas - releases acid neutralizers

  8. Gallbladder - stores bile and releases it into small intestine when needed

  9. Small Intestine - digests food and absorbs nutrients into blood or lymph

  10. Large Intestine - absorbs water and some vitamins. Collects excess water and passes waste material.

  11. Anus - opens to allow waste to leave the body