Download Worm Dissection

Worm Dissection
2014
WARNING: STAY FOCUSED IN
THIS LAB
NO MESSING AROUND OR YOU
WILL RECEIVE A 0!!
Identification of External Anatomy
Caudal
Dorsal Side
Ventral Side
Metameres
Clitellum
Setae
Mouth
External Anatomy
Metamere or segment
External Anatomy
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Dorsal – It is darker and smooth.
Ventral – Lighter and a rough feel.
Setae – Bristles that aids in locomotion .
Metamere – Body segments
Clitellum – Light colored section that
secretes muscus for copulation and
movement.
• Caudal – Opposite end from the mouth.
Internal Anatomy
Cerebral ganglion
Esophagus
Pharynx
Protonephridia
Septa
Seminal vesicles
Aortic Arches
Crop
Stomach
Intestine
Gizzard
Dorsal blood
vessel
Reproductive System
Digestive System
Internal Anatomy
Excretory System
Internal Anatomy
• Aortic Arches – 5 that
pump blood through the
worm.
• Seminal Vesicles – Large,
light colored organs that
contain the sex organs.
• Crop – Food stored
before entering the
gizzard.
• Gizzard Contains soil to
help grind for digestion.
• Intestine – Food is
digested and nutrients
are absorbed.
• Dorsal Blood Vessel – A
large blood vessel at the
top of the digestive track.
• Cerebral Ganglion – This
is the brain.
• Protonephridia – Filter out
nitrogenous wastes.
Cross section of Earthworm
More Internal Anatomy
• Coelom – This is the body cavity filled with
fluid that acts as a skeleton.
• Typhlosole – This is a ridge inside the
intestine from the dorsal side. It enlarges
the surface area of the intestine, which
increases the efficiency in absorbing food.
FORMAL LAB WRITEUP
Title, Labeling
• You will have your name and period in the
upper left hand corner.
• The title of your lab will be in the center of
your sheet and it will be underlined.
Objective: (10 points)
• Objective: Learn the anatomy of the
Earthworm through dissection.
• Materials: (5 points)
Scalpel
T Pins
etc…
Procedures
• 1) I Gathered materials and read
instructions.
• 2)…..
• FOR THIS LAB YOU NEED 15 to
20 PROCEDURES!!!!
• These need to be written in
COMPLETE SENTENCES!
Observations – 40 points
• Respiratory/Circulatory drawing – Only
include the organs used in these systems.
Sections need to be defined and labeled.
Drawings should be neat and labeled.
• Digestive system - Only include the
organs used in this system. Sections need
to be defined and labeled. Drawing should
be neat and labeled.
Observation continued..
• Cross section of metamere. Label and
define all terms on the section.
• Nervous system – Draw only the nervous
system. Do not include organs used in
other processes. Define all the terms.
Uncertainties (10 points)
• This is what could have gone wrong with
your experiment and how it would affect
your end results.
Conclusion: (10 points)
• Explain the circulatory, respiratory,
excretory and nervous system of the
worm.
• Neatness and format count.
• You need to use correct punctuation and
grammar at all times! YOU WILL LOSE
POINTS IF YOU don’t do this.