Biology 11

25.4 – Phylum Annelida

Body Structure of Segmented Worms Annelids undergo _________________ development. Include earthworms, marine worms, and parasitic leeches __________ and have a _____________ Rigidity in annelid segments creates a _______________ skeleton that muscles can push

against. Segmentation also permits segments to move ____________ of each other and enables

a worm to survive damage. Segments can be _____________.

Feeding and Digestion Running through all earthworm ___________ from the mouth to the anus is the

digestive tract.Circulation

Most annelids have a ___________ circulatory system. Respiration and Excretion

Earthworms take in oxygen and give off carbon dioxide through their __________ skin.

Aquatic annelids have __________ for the exchange of gases in the water. Segmented worms have two _____________ in almost every segment.

Response to Stimuli The ___________ segments are modified for __________ the environment.

Movement The earthworm contracts ___________ muscles running around each segment. This ____________ the segment and causes the fluid in the coelom to press

____________like paste. The fluid pressure causes the segment to get _________ and ______________.

Biology 11

The earthworm contracts the ___________ muscles that run the length of its body. This causes the segment to _____________ and return to its original shape, pulling its

posterior end _______________ and resulting in movement.Reproduction

Reproduce both ___________ and ____________ Sperm are passed between two worms near segments called the _____________. The clitellum produces a ____________from which the young earthworms hatch

Diversity of Annelids Annelida

Typically live underground in _______________ habitats.

___________ the soil as they feed off of it.

Earthworms and their relatives

Polychaeta Typically live in ______________

environments Bodies have _____________ for

swimming and crawling Filter feeders who trap food in

___________on their bodies.

Hirudinea Typically live in

___________environments Most are ______________ Leeches have adapted chemicals to stop

_____________ of blood.