BIO 1130 Lecture Notes - Lecture 15: Photic Zone, Cambrian Explosion, Zygote

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

The hydra have a typical polyp structure, oral opening, no anal opening, there are two layers of cells the inner endoderm (te gatrodermis) this is where we will have cell that aobsrobe the nutrients Then we have digestive outside we have the epidetermi (if you look at the derivatives and nerve cells are always ectodermal a well) We can get cells to contract without epithelial musculature with out having muscle contraction. We end up with: strands of actin with myosin as just fibres within the cell. What we find is in the inner surface of the cnidaria these fibres are arranged in a circular array; on the epidermis they are arranged longitudinal. The circular and longitudinal array means that we have a muscle that can counter ____ the muscle. It can stretch muscles back the original length. This is the feature of a hydrostatic skeleton we see this in a variety of different locations.