Invertebrates
What is the only characteristic an animal must possess to be considered an invertebrate?
The animal must lack a backbone!
Sponges are often called...
filter feeders
The body of cnidarians, or the jellyfish, exhibits what kind of symmetry?
Radial Symmetry
Bonus point: What is Radial Symmetry?
Flatworms and roundworms exhibit what kind of symmetry?
bilateral symmetry
What phylum do roundworms belong to?
Phylum nemotoda
All invertebrates have an...
Exoskeleton
Where do sponges typically live?
In water, mostly in oceans.
What kind of exoskeleton does a jellyfish have?
A hydroskeleton
Flatworms belong to what phylum?
Platyhelminthes
Most roundworms and flatworms are parasitic, but can also be "free-living." Explain.
Free-living means that they do not need a host to feed off of to survive.
Which invertebrate phylum has the most animal species?
Arthropoda
Adult sponges are ___________, meaning they are unable to move from place to place and are permentantly attached to solid objects in the water.
sessile
In the inside of a jellyfish, the inner layer, known as __________________, is where the jellyfish digests its food. It is also where their reproductive organs are located.
gastrovascular
Name the three parts of a flatworm's nervous system.
- Ganglion (simple brain)
- Longitudinal nerve
- Transverse nerves
Where do roundworms/flatworms typically live?
The study of animals is known as
zoology
False. Sponges may reproduce sexually or asexually.
Jellyfish have ____________________, or painful stingers found in special cells on the outer layer of their tenticles
nematocycts
Why are flatworms sometimes called "cross-eyed" worms?
Planarians do not see objects or colors, but rather detect the absence and presence of light.
- pinworms
- hookworms
- vinegar eels
True or False.
Animals are eukaryotic, can be single-celled, have organized tissues, and are consumers.
False!
ALL animals are multicellular organisms.
What is the typical diet for a sponge?
Sponges typically eat algae and bacteria. They purify 97% of the bacteria from the ocean!
True or false. Jellyfish use their tentacles to swim.
False. To swim, jellyfish have a set of muscle fibers around their rim that contract. This forces the water out of the jellyfish's gastrovascular cavity and moves the jellyfish up or down in the water as they drift in the current.
Planarians reproduce sexually and asexually. They are also hermaphroditic. Explain what hermaphroditic means and how planarians reproduce asexually.
Hermaphroditic- having both male and female reproductive organs
Asexual reproduction - a planarian may be cut in half and eventually will grow into a completely new planarian. Even small pieces can even grow into new adults
Explain the process of roundworm digestion in humans.
1) Roundworms release eggs into the host's intestine, those eggs then exit in the feces.
2) When the tiny eggs are swallowed by humans the eggs hatch.
3) The young larvae burrow into the intestinal wall of the new host and enter the bloodstream
4) They eventually reach the lungs, travel up the throat, and are re-swallowed
5) In the intestine again, the larvae grow into adult worms
6) The cycle repeats