In: Biology
1. What is an animal? List characteristics describing animals.
2. What is the Cambrian Explosion?
3. Is the kingdom “Animalia” monophyletic or polyphyletic?
4. How do you describe invertebrates? What are examples of invertebrates?
5. List criteria that are used to classify invertebrates.
1. An animal is a living organism that is heterotroph, typically have specialized sense organs and nervous system and able to respond rapidly to stimuli. Characteristics of animals include multicellularality, eukaryotic cell structure, specialized tissues, sexual reproduction, blastula stage of development, ability to move, heterotrophy, advanced nervous system.
2. Cambrian Explosion is an event in the fossil record where nearly all modern animal body plans and phyla appear within a period of 20 million years at the beginning of this period. It started at the very bottom of the ocean and happened around 540 million years ago. The creatures that came out of it include jellyfish, snails, and starfish.
3. Monophyletic because they all evolved from a common ancestor.
4. Invertebrates are animals derived from Notochord that do not possess or develop a vertebral column. Examples includes arthropods, mollusks, annelids, and cnidarians.