BIOL 005B Lecture Notes - Lecture 4: Zygote, Collagen, The Animal Kingdom
Document Summary
Biol 005b lecture 4: introduction to animal diversity. What are animals? embryonic layers other life-forms. The animal kingdom extends far beyond humans and other animals we may. 1. 3 million living species of animals have been identified. Animals are multicellular, heterotrophic eukaryotes with tissues that develop from. There are exceptions to nearly every criterion for distinguishing animals from. Several characteristics, taken together, sufficiently define the group: Animals are heterotrophs that ingest their food. Animals cannot construct all of their own organic molecules (unlike plants) Animals do not feed by absorption (unlike fungi) Animals ingest food then use enzymes to digest it within their bodies. Their bodies are held together by structural proteins such as collagen. Nervous tissue and muscle tissue are unique to animals. Most animals reproduce sexually, with the diploid stage usually dominating the. After a sperm fertilizes an egg, the zygote undergoes rapid cell division called. Cleavage leads to formation of a blastula.
