Worms: Types, Structures, and Reproduction in Biology

What are the three major types of worms?

Flatworms, roundworms, and segmented worms.

To which phylum do flatworms belong?

Phylum Platyhelminthes.

To which phylum do roundworms belong?

Phylum Nematoda.

To which phylum do segmented worms belong?

Phylum Annelida.

What is a common characteristic of all worms?

They have long narrow bodies with no legs.

Bilateral

3 layers endo, ecto and meso

have cephalization

Have no skeletal system

What is the main difference between flatworms, roundworms, and segmented worms?

Flatworms have a flat body, Acoelomates, one opening to the digestive tract, no circulatory system, no seg.

Roundworms have a round body with pseudocolomate, Two openings, no circulatory system, no seg.

Segmented worms have a segmented body with a coelomate, Two openings, have a closed ciculatory system, have segmentation

What is the brain of a worm called?

Cerebral ganglion.

How can worms reproduce? How and which worms are different?

Worms can reproduce asexually and sexually.

Flatworms and earthworms are Hermaphrodites meaning they gave both sex organs and therefore can act as both genders.

What are planarians?

Free-living flatworms that are scavengers or predators.

Types of Platyhelminthes

Planaria and tapeworms

What are segmented worms commonly known as?

Earthworms, leeches, and seafloor worms.

What type of circulatory system do segmented worms have?

A closed circulatory system.

How do earthworms benefit the environment?

Their burrowing aerates the soil and their droppings make excellent fertilizer.

What is a characteristic of segmented worms' body structure?

They are made up of segments which are linked sections.

What is the feeding tube used by planarians called?

Pharynx.

What happens when some worms are cut into pieces?

A whole new worm can grow from each piece.

What do many flatworms rely on for survival?

They are often parasites that take food from a host.

What is the role of the nerve tissue in segmented worms?

It runs down the entire body of the worm.

What environments can roundworms inhabit?

They can live in sandy beaches, forest soil, and inside other organisms.

What is the significance of the closed circulatory system in segmented worms?

It keeps the blood enclosed inside tubes, similar to human circulatory systems.

What do setae do and how many are per each segment?

setae point in both directions, help the worm move around in locomotion, in dirt and other material, they are found four 4 pairs which have 8 total per segment.

Types in the is phylum Neatoda

Flatworms—> Ascaris

Female: no hook

Male: hook (harder to find)

Which surface of the earthworm in darker in color- dorsal or ventral

The dorsal (top) surface of the earthworm is darker and more heavily colored than

The list in sequence of structures that food passes through after being taken in by the earthworm

Mouth, Pharynx, Esophagus, crop, Gizzard, Intestine and anus

The earthworm does not undergo self-fetilization. what advantage (if any) to being hermaphroditic

It can mate with any worm no matter the gender since it has both genitals

Three features of Earthworm that ditinihish it from the other members of Phylum Platyhelminthes and Phylum Nematoda

Segmented, colomate (body cavity), have a closed circulatory system (veins)

What is the difference between dorsal and ventral

Dorsal (smooth side) is on the top, and ventral is on the bottom (Stomach) has setae

Roundworm anatomy

pic

What do earthworms feed on

Soil

The clitellum is closer the ..

mouth and anterior end (top)

the external anatomy of a worm(earthworm) pt. 1

pic

the external anatomy of a worm(earthworm) pt. 2

pic

Earthworm digestive system

pic

Circulatory system

closed pic

Internal anatomy of an earthworm from lab

pic

External anatomy of an earthworm pt. 3

pic

Pharynx function

ingest food

esophagus

leads to the the thin walled crop—> storage sac

Gizzard

food passes through crop (muscular)

Intestine

Ground up food though it

Ascaris labeling internbal

Phylum Platyhelminthes- Planaria anatomy

The Auricles in flatworms (planarians) are specialized, ear-like projections on the sides of the head recoptors of motion and toach

Gastrovascular cavity: central, sac-like digestive chamber with a single opening that functions as both mouth and anus,

Posterior vs antetior

post- back

ante- front