We are studying the INVERTEBRATES.
Definition: they are animals with no bones or skeleton
-Size: usually very small
-Shape: either symmetrical or irregular
-Body cover: they are protected by shells or exoskeletons
They can live in the sea, in fresh water or land.
Invertebrates are OVIPARUS: they are born from eggs.
INVERTEBRATE GROUPS:
+ SPONGES: irregular bodies. They can't move. They attach themselves to a surface. They filter water and retain the nutrients
+ CNIDARIANS: they are marine animals. They have a jelly aspect. They can move or be attached to rocks.
+ WORMS: they have long, soft bodies. They can be aquatic or terrestrial. Many of them are parasites.
+ ECHINODERMS: they are symmetrical and usually have 5 parts. They often have spines.
+ ARTHROPODS: They are covered by a hard exoskeleton. They can be either terrestrial or aquatic.
+ MOLLUSCS: they have a soft body coverd by one or two shells.
Now it's time for you to study hard this lesson.
See you!
Luisma
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