12C Flashcards
- What does bilateral symmetry mean?
There are two equal sides to the animal. They are mirror images.
- What does free living mean?
The worm does not depend on another organism for survival
What type of symmetry does a planarian have?
Bilateral symmetry
- Hoe many possible planes are there to divide a bilateral planarian?
One
- Give an example of a flatworms?
Planarian
- Which phylum do flatworms belong to?
Platyhelminthes
- Some flatworms are free living. What does this mean?
They do not depend on other organisms for survival
- Are most flatworms parasitic?
Yes
What does parasitic mean?
They live in other organisms called hosts and get their nourishment from the hosts
- Name three parts of the planarians nervous system
2 longitudinal nerves that run down the sides of the body. There are ganglions at the top of each longitudinal nerve that control the planarians responses to stimuli. Transverse nerves connect the longitudinal nerves
- What is the name for an invertebrates response center?
Ganglion also know as a simple brain
What are four major stimuli that plantains respond to?
Light, chemicals, touch, water
What is a stimulus?
Something that causes a reaction to an organism
Explain the planarian responses of the nervous system…
Nerve cells receive the stimulus. They convert the stimulus to impulses which travel along the nerves to the ganglion. The ganglion receives the impulses and then sends other impulses to various structures of the planarian causing it to respond.
How many eyespots does the planarian have?
Two