BIOL 1202 Lecture Notes - Lecture 32: Body Plan, Gastrulation, Blastocoel
Document Summary
The main distinguishing features of the kingdom animalia are. In addition to these characteristics, as animals evolved from the animal-like protists, they developed more complex and organized bodies. The closest relative to the animals are protists in the clade known as opisthokonts (see fig 32. 3) Cellular specialization or partnership between specialized cells may have been what ultimately lead to the animal kingdom. Cellular specialization leads to the development of tissues, which then can lead to the combination of tissues into an organ. Organs may then become arranged into organ systems. Tissues are specialized cells with a common structure and function that are grouped together. Organs are centers of bodily function, which are usually made up of different tissues. Organ systems are groups of two or more organs that function together to perform a common task (e. g. , digestion, gas exchange, reproduction)
