Study Guides (248,043)
Canada (121,253)
BIOL 111 (52)

Lab 6 - Phylum Annelida.docx

5 Pages
Unlock Document

Biology (Sci)
BIOL 111
Suzanne Gray

LAB 6INVERTEBRATES IPhylum Annelida Annelida means little ringsPhylum contains segmented wormso Earthworms o Tubeworms o LeechesBodies are composed of many essentially similar segments Phylum AnnelidaCommon EarthwormDaytime earthworms remain below the surface to avoid drying outNighttime earthworms come to the surface to collect plant debris for food and to mateExternal AnatomyCovered in a thin transparent cuticle secreted by the epidermis o Protects the animal from desiccationo Glandular cells of the epidermis secrete mucus which also adds in protection locomotion and respirationBilaterally symmetricalAnterior end is more cylindrical and thicker than the posterior end o The Clitellum thickened band around the middle of the earthworm that is located closer to the anterior endThe ventral surface of the earthworm is light and flatter than the dorsal surface Which end elicits a stronger response The anterior end should elicit a stronger response because of the large concentration of neurons located thereEarthworms emerge from their burrows anterior head first why The majority of neurons including sensory cells are located in the anterior end It can use these receptors to determine the relative condition and safety of the environment it is emerging into Evolutionarily speaking those earthworm that did not show this behavior ie they emerged posterior end first were removed from the gene pool Thus their genes for this behavior were not passed on to the next generationSegments on each segment except the first and last there are four pairs of posteriorfacing setate bristles which anchor the earthworm to the substrate while the rest of the body is moving forwardSegment 1 the mouth is located here small ventral slit o Prostomium fleshy lobe that precedes the mouth
More Less

Related notes for BIOL 111

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.