Adaptations for nutrition Flashcards
How do unicellular organisms obtain there nutrients
- amoeba move around prey and enclose in a food vacuole
- enzymes are released from lyosome and fuse with the food vacuole and the prey is digested
- products of digestion are abrobed into the cytoplasm and the undissolved waste is egested by exocytosis
Describe the gut of a hydra
- single food source
- undifferentiated sac like gut with a single opening
Describe the gut of an earthworm
- varied foods
- tube gut with different openings for ingestion and egestion and specialised regions for the digestion of different food
Describe the gut of a human
- omnivorous diet
- specialised regions of the gut
- the gut wall contain : serosa, longitudinal muscle, circular muscle, sub mucose, mucosa, epithelieum
Describe the structure of serosa
tough outer coat of connective tissue
Describe the structure and function of the muscle in the gut wall
- longitudinal muscle contracts to shorten the fut
- and cicular muscle contrats to reduce diameter
- these waves of contraction are called peristalsis force food along the gut
What is the structure and funcition of submucosa
- contains blood and lymph vessels
- remove digested food products
Describe the structure and function of mucosa
- inner layer that secretes muscus for lubrication
- in some area it secretes digestive juices in others it absorbs products
Describe the structure of the epithelium
- layers of cells in contact with food
Describe the term autotrophic
makes complex organic mlecules from simple inorganic ones
Describe the term heterotrophic
consume complex organic food molecules
Describe the term photoautotrophic
use light as a source of energy for synthesis of food
Describe the term chemautotrophic
oxidise inorganic molecules to provide energy for the synthesis of food
Describe the term saprophytic
external digetion of ffood using seccretion of enzymes followed by absorption of the products of digestion into the organism eg fungi
Describe the term holozoic
internal digestion of food involved ingestion,absorption, assimilation and egestion