Allergy Tests. Guide. Allergy testing involves having a skin or blood test to find out what substance, or allergen, may trigger an allergic response in a person.Skin tests are usually done because they are rapid, reliable, and generally less expensive than blood tests, but either type of test may be used.llergy blood tests look for substances in the blood called antibodies. Blood tests are not as sensitive as skin tests but are often used for people who are not able to have skin tests. The most common type of blood test used is the enzyme-linked immunosorbent assay (ELISA, EIA).
Sensory Structures of a Flatworm. Flatworms live in many environments. Jupiterimages/Photos.com/Getty Images. Flatworms, also called planarians, belong to the phylum Platyhelminthes. Characterized by flat bodies, they have no circulatory or respiratory organs and a very simple digestive tract.This body plan limits them to very small, flat shapes to allow them to absorb oxygen and moisture.owever, a flatwormâs body contains the beginnings of more complex structures found in other animals. For example, eye spots resemble the ancestral forms found in more complex animals. Understanding flatworm sensory structures can help you understand the origins of these organs.
Figure 1: Structure of planarian CNS (A) Ventral view of whole-mount in situ hybridization with a DjPC2 (Dugesia Japonica Pro-hormone Convertase 2) RNA probe as a pan-neural marker. Anterior is up and posterior is down. The white region in the center of the body is a pharynx. (B) A model of the planarian brain.n the first study on the organization of the planarian brain, a homolog of the homeobox-containing gene Orthopedia (Otp) from planaria, Djotp, was isolated. Djotp is specifically expressed in the branch structures of the brain (Umesono et al., 1997).