BioLab7 Flashcards
Where are annelida found?
In moist terrestrial environments.
What are annelida?
Segmented worms.
What type of symmetry do annelids have?
Bilateral.
What type of digestive system do annelids have?
Tubular digestive tract.
What is the body plan of annelids?
Triploblastic coelomates.
How do annelids move?
Segmentation. Contractions of muscles against the fluid within the coelom allow for powerful forward locomotion.
What type of skeleton do annelids have?
Hydrostatic.
Where do Lumbricus live?
In burrows two metres deep within moist soil during the day, come out at night to feed on organic detritus.
What is the protective covering on the Lumbricus that must be kept moist and allows for respiration?
Cuticle.
What is the clitellum?
A structure that secretes a thick mucus to attach worms together while they exchange sperm. Later this structure produces a cocoon which houses the fertilized eggs until a young worm develops
How do Lumbricus reproduce?
Hermaphroditic; 3 large seminal vesicles that store sperm and two small seminal receptacles that receive sperm.
What is firmness in the earthworm due to?
Pressure of the coelomic fluid (hydrostatic skeleton).
How do earthworms move?
alternating waves of contraction muscles moving posteriorly along the worms body. Each segment has circular and longitudinal muscles which act against the fluid within the coelom of that segment antagonistically to each other.
Describe Lumbricus Ingestion and Digestion.
Pharynx takes food from mouth. Food goes through esophagus and is temporarily stored in the crop. It then passes to muscular gizzard to be ground up. It is digested and absorbed in the long intestine and undigested material is eliminated through the anus.
Who are friends of the Lumbricus?
Nereis (sandworm) and Leeches.
What does the phylum Mollusca consist of?
clams, oysters, squids, octopus, snails, and slugs.
What is a defining feature of Mollusca?
Their soft bodies.
What are the 3 common regions of the Mollusca body?
Foot, Visceral mass, and Mantl
What does the visceral mass contain?
The internal organs.
What is the mantle?
A fold of tissue which secretes the shell.
What is the symmetry of mollusks?
Bilateral.
What is the body plan of mollusks?
Triploblastic coelomate.