Digestion in Animals – Part 1. All Living things get food somehow. Most unicellular organisms, like bacteria, secrete enzymes and absorb nutrients. However, In the Protist Kingdom, unicellular organisms are very specialized to obtain food. Ingestive heterotrophs or autotrophs. Amoeba.
Digestion in Animals – Part 1
Water & waste
Water & food
Have you ever been stung by jellyfish?
JELLYFISH - MEDUSAS
Polyp body form
Digestion in cnidarians Extracellular – occurs In gastrovascular cavity - enzymes are released from cells lining cavity and food is digested within the cavity. - Nutrients are absorbed by cells in cavity and waste is expelled out the mouth (yuch!).
Coral is actually a colony of polyps, most of which are the size of a single hydra – they just make a case around them for their home.
Here are a variety of anemones – polyp body form
These are free-living flatworms
Tapeworms – the ultimate parasite – the only highly developed system is its reproductive system – hermaphroditic
Digestion– absorbs host’s already digested food.
Scolex – head with hooks and suckers
Look like threads
in the microscope
Enters through soles of feet
Larvae in human feces
Causes fatigue – may cause physical and mental retardation if children have it
From undercooked pork
Causes severe muscle aches when larvae migrate from intestine to muscles
This lesion is caused by a nematode infestation
Mouth pharynx esophagus crop gizzard intestine anus
1 2 3 4 5 6 7
Trap food in
Mucus on gills
Both food and
Octopus and squid catch live prey using their tentacles and eat them
Sea urchins, sand dollars, and starfish
Some of these are insects, some are not….
Can you tell which is which?