BISC 120Lg Lecture Notes - Lecture 20: Mesozoic, Paleozoic, Cambrian
20 Apr 2016
School
Department
Course
Professor
Document Summary
Heterotrophic: unable to make their own food, instead live on compounds produced by other organisms this makes them consumers: animals= digest & get nutrients from digesting. Multicellular: animal cells lack cell walls so structural support comes from external proteins, e. g. collagen. Tissues that develop from embryo layers: the cells of most animals are organized into tissues which are: groups of similar cells that act as a functional unit, development of tissues from layers of the embryo. Blastula= composed of many cells but is hollow, composed of 1 layer of cells and an empty cavity. Gastrulation: the layer of cells grows inward into the blastocell and fill the empty cavity cell and create a second layer of tissue. Archenteron: the space inside the endoderm, this will become the digestive cavity where digestive organs will be. Fossils and molecular estimates place the origin of animals around 750 mya. Dna indicates that choanoflagellates and animals are sister groups.
