Feeding and Digestion

• Animals obtain food through various methods such as:

  • Filter feeders: catch algae and small animals using modified gills or structures as nets
  • Detritivores: feed on detritus, obtaining nutrients from bacteria and microorganisms
  • Herbivores: eat plants or algae
  • Carnivores: eat other animals
  • Omnivores: eat both animals and plants
• Symbiosis types related to animals obtaining food:

  • Parasitic Symbiosis: parasites live within or on a host organism, feeding on tissues or body fluids
  • Mutualistic Symbiosis: benefits both participants
  • Commensalism Symbiosis: one species gains benefits while the other is neither benefited nor harmed
• In the context of digestion in animals:

  • Simple animals like sponges digest food inside specialized cells
  • More complex animals break down food outside cells in a digestive cavity and absorb nutrients
  • Invertebrates and vertebrates digest food through a digestive tract with two openings
• Specializations for different diets in animals:

  • Carnivores have sharp mouthparts to capture and process food
  • Herbivores have mouthparts adapted for rasping or grinding plant cell walls
  • Ruminants like cattle have a rumen where symbiotic bacteria digest cellulose, regurgitating and rechewing food for better digestion
• Types of teeth

  • Incisors; well developed in herbivores, used for cutting
  • Canines; well developed in carnivores, used for tearing meat