Module 2 - Introduction to Animal Diversity Flashcards
What are some characteristics of animals?
Heterotrophic, multicellular, nervous and digestive system, spine and/or skeletal structure, no cell wall, able to (mostly) sexually reproduce, able to move, extracellular matrix, related at a molecular level
When did animal life appear around?
More than 600 mya
Describe the Cambrian Explosion
Occurred 530 mya, appearance of many animal phyla, many phyla no longer exist, larger animals and first vertebrates, movement onto land
What are the five grades of organization?
Protoplasmic (organelles), cellular, tissue, organs, and organ systems
What are the types of body symmetry?
Asymmetric, radial, and bilateral
Asymmetric Body Symmetry
No symmetry
Radial Body Symmetry
Multiple axis of symmetry
Bilateral Body Symmetry
One axis of symmetry, includes cephalization
What kind of animals have an asymmetry symmetry?
Sponges
What kind of animals have a radial symmetry?
Cnidaria (jellyfish)
What kind of animals have bilateral symmetry?
Crabs, mammals, most animals
What is another kind of symmetry (other than asymmetry, radial, and bilateral) that is not present in animals?
Spherical
What are germ layers?
Embryonic cell layers during gastrulation
What is ectoderm and what does it form?
The outer layer; forms skin and nervous system
What is mesoderm and what does it form?
The middle layer; forms muscles, blood, and other organs
What is endoderm and what does it form?
The inner layer; forms the lining of the digestive tract
What do you call an animal with two germ layers?
Diploblastic
Diploblastic - what layer do they not have?
Two germ layers, no mesoderm
What symmetry do diploblastic animals have?
Radial
What do you call an animals with three germ layers?
Triploblastic
What symmetry do triploblastic animals have?
Bilateral
Blastopore
A small opening in the embryo during gastrulation
What does the blastopore become in protosomes?
The mouth
What does the blastopore become in deuterostomes?
The anus
What is a body cavity?
Internal space where an animal keeps its organs
Coelom
Fluid-filled body cavity
What are the three types of coeloms?
Coelomates, pseudocoelomates, and acoelomates
Coelomates
Animals with a true coelom or their body cavity is lined with mesoderm (earthworms)
Pseudocoelomates
Animals with a coelom that isn’t lined with mesoderm (nematodes)
Acoelomates
Animals without a coelom, instead they have a cavity filled with mesoderm (flatworms)
Segmentation
Repetition of similar body segments
What are the major animal phyla?
Ctenophora, porifera, cnidaria, platyhelminthes, rotifera, bryozoa, brachiopoda, mollusca, annelida, nematoda, arthropoda, echinodermata, and chordata
What are the closest living relatives to animals?
Choanoflagellates
Invertebrates vs. Vertebrates
Invertebrates have no backbone (90% of all animals) vs. Vertebrates have a backbone
What’s included in a vertebrate?
Vertebral column, a cranium, an endoskeleton of cartilage or bone = main 3. They also have a neural crest and a diversity of organs
Porifera - Basic characteristics
No germ layers (neither diploblastic or triploblastic), asymmetric, cellular level of organization, no nervous system
Porifera - Choanocytes
Flagellated cells that filter food through water
Porifera - Amoebocytes
Interior of the sponge that aids in digestion, secretes spicules, and reproduction
Porifera - Pinacocytes
Outer layer of a sponge that maintains structure and size
Porifera - Spicules
Rigid structures providing protection and support
Porifera - Spongin
Structural support