Lesson 8: Animals Flashcards
What are animals?
- Multi-cellular organisms with tissues and, usually, organs and organ systems
- Undergo larval or embryonic development
Larval development?
- means that the young look very different from the adult
Ex: caterpillars into butterflies
Embryonic development?
This type of development means that the young version is a mini-version of the adult
Zoology?
the branch of science that studies animals
How many phylas are there in the animal kingdom? what are they?
8 phyla in total to know, but there are 7 invertebrate phylas:
- porifera (sponges)
- cnidaria (jellyfish)
- platyhelminthes (flat worms and round worms)
- annelida (segmented worms)
- mollusca (clams, mussels, snails)
- arthropoda (crabs, lobster, insects, spiders)
- echinodermata (sea urchin, sand dollar)
What are the two big groups?
- invertebrates
- vertebrates
Invertebrates?
- they have no backbone
- 97% of all animals
- there are 7 phyla
Vertebrates?
- the chordata phyla
- they have a backbone
- 3% of animals
Protostomes vs deuterostomes, what are they?
terms that we use to categorize members of major taxonomic groups of animals by how they develop as embryos
Protostomes?
- first opening of the organism becomes the mouth
- simple organisms (arthopods, flatworms, annelids)
Deuterostomes?
- the first opening of the organism becomes the anus (the mouth develops later)
- complex organisms (humans, tigers, monkeys)
Porifera characteristics
- Have no definite shape – asymmetrical;
- No tissues or organs
- Colony of specialized cells (they are dependent on these specialized cells in order to perform specific functions in their bodies - since they do not have organs!!)
- Immobile
- Good powers of regeneration (parts or whole body)
- Skeleton of sponging (modified collagen) and spicules (hard crystal material)
Cnidarian characteristics
- Jellyfish, corals, anemones
- Radial symmetry (can be divided at any point into 2 matching halves)
- Primitive nerve net but no brain (very primitive/simplistic nervous system)
- 2-way digestive tract (a single opening that serves as both the mouth and anus, very simple digestive cavity that acts as both the stomach and intestine)
- Stinging cells for capturing food.
Platyhelminthes characteristics
- First animals to exhibit bilateral symmetry (right and left sides are mirror images of one another)
- Have primitive brain
- 3 tissue layers (endoderm, mesoderm, & ectoderm)
- Includes free-living flatworms and parasitic flatworms (tapeworms, flukes)
Annelida characteristics
- Earthworms, sandworms, leeches
- Slightly more complex body plan, have many segments (like many rings joined together)
- Complete one-way digestive system/tract with mouth and anus
- Have well-developed digestive and circulatory systems (i.e. closed circulatory system - blood is limited to vessels)
Mollusca characteristics
- Includes: snails, slugs, nudibranchs, chitons, limpets, clams, oysters, squid, octopus, nautilus, etc.
- Either have no shell, one shell, or two shells
- Contain a mass of soft flesh that covers the soft body and encloses internal organs
- Many have hard mouthparts used for feeding (radula in gastropods, beak in cephalopods).
Arthropoda characteristics
- Includes: insects, crustaceans, centipedes, millipedes, and arachnids (spiders)
- Exoskeleton made of chitin (polysaccharide)
- Must shed their exoskeletons in order to grow (they can develop a new exoskeleton once larger)
Echinodermata characteristics
- Includes: sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids
- Reverted back to radial symmetry (radial in adults / bilateral in larvae)
- Tube feet and water vascular system (a hydraulic pressure system that help with locomotion, feeding/nutrient cycling, and respiration/gas exchange
- Most exhibit pentamerism (consisting of 5 parts)
How many classes of vertebrates are there?
5 classes
What are the 5 classes of vertebrates?
- class fish
- class amphibia
- class reptilia
- class aves (birds)
- class mammalia
