Exploring an Earthworm
Abbey Boggs 4/7/14 Mitcham-PAP Bio-Period 6
Lab Objectives
Lumbricus terrestris
Adaptations
Earthworms have adapted to living in the soil by having:
- A mucus coating that aids in oxygen passing through the skin
- A muscular pharynx that helps the earthworm clear soil out of the way
- Sand grains in the gizzard that aid in grinding food
An Earthworm's Digestive System
Functions of an earthworm's digestive organs
1. Gizzard: The gizzard grind up food, which is aided by sand grains.
2. Crop: The crop provides temporary storage for food.
3. Mouth: The mouth obtains food for the worm.
4. Pharynx: The pharynx helps the mouth to suck in food and soil.
5. Esophagus: The esophagus is where food passes through to get to the intestine.
6. Intestine: The intestine chemically breaks down food using enzymes
7. Anus: The anus excretes wastes from the earthworm.
What does an earthworm's digestive system do?
The digestive system of an earthworm functions to absorb nutrients from soil that are essential to the earthworm's survival. When an earthworm sucks in soil, the material travels all the way to the gizzard, where the materials are then ground up by sand grains. After the food and nutrients have been digested, wastes leave the earthworm through the anus. The digestive system of an earthworm is closely related to an earthworm's muscular system, as the muscular pharynx and other muscles help the earthworm to obtain food and move that food along through the digestive system.
Human Impact and Influence
Symbiotic Relationships
Earthworms break down soil particles as a way of obtaining food, and in return, the soil becomes richer and microorganisms are benefited.
Cladogram
Where Earthworms are Located
Sources
http://www.encyclopedia.com/topic/Annelida.aspx/
http://animals.nationalgeographic.com/animals/invertebrates/earthworm/
http://www.soilhealth.com/soils-are-alive/how-do-soil-organisms-interact-with-each-other/p-01.htm
http://www.bbc.co.uk/nature/life/Lumbricidae#p00thgkz
http://www.biologycorner.com/worksheets/earthworm_dissection_key.html
http://animals.nationalgeographic.com/animals/invertebrates/earthworm/
http://www-tc.pbs.org/wgbh/nova/education/activities/images/2905_examplecladogram.gif