Worrisome Worms!

By: Elizabeth Swinehart Pd.4

How to classify a worm?

All Worms Have...

-Bilateral symmetry

-Cephalization (can respond to environment with sensory organs)

-No true limbs to move


What to know...

-also known as flatworms

-They have no true body cavity

-scavenger on the food chain

-They c0nsist of 3 germ layers

- Are classified into 3 classes (Cestoda, Turbellaria, Trematoda)

Turbellaria (non-parasitic)

-Prefer dark environments

-Have no true skeleton

-No circulatory system

Trematoda (parasitic)

-Have suckers to attach to its host

-live in different body forms (egg, cyst, larvae, fluke)

-Cysts allow it to lay dormant until consumed and eggs hatch


Be aware of...

-they are also known as roundworms

-Have a hollow fluid filled cavity

-complete digestive tract

- use a cuticle which protects them form the inside digestive tract of their host

Soil Nematode (free living)

-Help with agriculture

-Do not possess a host

Trichinella (parasitic)

- Infect humans and mammals

-Live in the intestines

-Ingested by eating raw meat (unless frozen)

-form cysts


Knowing the basics...

- Their body is divided into segments

-Coelomate body plan

-evolved from primitive flatworms

Oligochaeta (free living)

-Also known as an earth worm

-Lives under the soil

-is nocturnal (active at night)

-circular muscles used to move the body

Hirudinea (parasitic)

-commonly referred to as a leech

-Will attach to the outside of a hosts body using hooks/ suckers

-feeds off of blood/fluid