Animal Diversity: I Flashcards
What is zoology?
Scientific study of animal life
Define an animal (Metazoan).
Multicellular, ingest food heterotrophs before digestion, mostly mobile, no cell wall, diploid
How many species of animals have been described?
1.3 million species in over 30 different phyla
What is Phylum Porifera?
Sponges
What are the main characteristics of Phylum Cnidaria?
Includes jellyfish, anemones, corals, hydras; sedentary or mobile; predatory; cnidocytes; medusa or polyp form
What are cnidocytes?
Stinging cells unique to cnidarians
Describe the body plan differences between Porifera, Cnidaria, and Bilateria.
Differences include body symmetry, tissue organization, and body cavities
What type of body symmetry do most Bilateria exhibit?
Bilateral symmetry
How many embryonic germ layers do Cnidarians have?
Two embryonic germ layers (diploblastic): endoderm and ectoderm
What additional germ layer do Bilaterians have?
Mesoderm
What is a coelom?
Body cavity between the body wall (ectoderm) and gut (endoderm), lined with mesoderm tissue
What are the three large clades that compose Bilateria?
- Deuterostomia
- Lophotrochozoa
- Ecdysozoa
What is the primary characteristic of invertebrates?
Lack a backbone
What are the two main features of most Lophotrochozoan taxa?
- A lophophore – a characteristic feeding organ
- A trochophore – a juvenile form
What is Phylum Platyhelminthes known for?
Flatworms, solid body cavity, simple digestive system, incomplete gut, amazing regenerative abilities
What are tapeworms and flukes?
Parasites of vertebrates found in Phylum Platyhelminthes
What are the three main body parts of Phylum Mollusca?
- Head-foot
- Visceral mass
- Mantle
What is the function of the radula in mollusks?
Feeding organ unique to mollusks, lost in some groups (bivalves)
What is Phylum Annelida commonly known as?
Segmented worms
What are the characteristics of most annelids?
Mostly bristle worms (polychaetes), all aquatic, maintain distinct head and parapodia
True or False: Cnidarians have a complete digestive system.
False
Fill in the blank: Most Lophotrochozoan taxa have either a _______ or a _______.
lophophore; trochophore
