BISC 120Lg Lecture Notes - Lecture 11: Hallucigenia, Eric F. Wieschaus, Burgess Shale
Document Summary
Bisc 120: general biology: organismal and evolutionary biology- lecture 11: Animals are heterotrophs that ingest their food. Need to consume organic substrates in order to grow. Animal cells do not have cell walls. Tissues are held together by structural proteins such as collagen. Have to use enzymes to break down the ecm. Not all animals (like sponges) have that many specialized cells, but in most, we do. Specialized neural and muscle cells are unique to animals. This is not seen in any other animals. Nervous system allows perception of noxious or favorable environmental conditions, predators, prey. Muscle tissue allows it to respond to stimuli. Mostly, a small flagellated haploid sperm fertilizes a larger, haploid, non- motile, polarized egg formation of zygote. Mitotic cell divisions called cleavage blastula. Gastrulation- invagination of blastula gastrula, endoderm, and ectoderm (specialization of cells) Morphological form that is quite different from the form you see.
