Review for a test
Mollusk - an animal with a soft body and no bones.
Example: clams, oysters, slugs, snails, squids and octopods
some have a hard shell that protects their body
Mantle - shell of mollusk, produces material to harden shell, grows as animal grows
some the mantle is a tough layer of skin
muscular foot - helps move and burrow into ocean floor
some have bivalves like oysters and clams
Radula - organ in snail that acts like a tongue with sharp teeth
octopus and squid have well developed brains and nervous systems
Adaptations - octopus and squid have jet like motion and squirt ink, snail has has a hard shell that protects itself.
Types of Mollusks
Roundworm - a worm with a round, tube like body. Most are too small to be seen.
digestive system with 2 openings
take in food and eliminate waste
muscles that run length of body
nervous system with brain and simple sense organs
Adaptation - parasitic roundworms live in other animal’s body to get food and protection.
How do roundworms and flatworms differ? Roundworms have a digestive tract with two openings, muscles running lengthwise; flatworms can regenerate and have eyespots.
Flatworm - has a flattened body, a digestive system with only one opening, and a simple nervous system. Example: Planarian
digestive system with only 1 opening and simple nervous system
live in both freshwater and saltwater
sense organs and nerve cords
a mouth and digestive system
can regenerate body parts that have been cut off.
Adaptation - Planarian can regenerate body parts
What characteristics do all flatworms share? They have flattened bodies, digestive system with only 1 opening, simple nervous system.
Segmented Worms - These are worms whose bodies are made up of connected sections, or segments. Example: earthworm.
body made up of connected segments
circulatory system - 5 enlarged tubes that act like hearts
nervous system - brain and main nerve
breath through skin
two sets of muscles that allow it to move
takes in food through mouth
Adaptation - breath through skin in the soil
What is the major difference between an earthworm and other worms? An earthworm has body systems that are more complex than those of other worms.