Chapter 31 Flashcards
Protostome animals
What are the two branches of protostomes?
Lophotrochozoa and Ecdysozoa
What are the importance of protostomes
- Major source of food for humans
- Pollination, soil preparation
- Include insects that damage and protect crops
- Provide valuable materials (silk, pearls)
- Common parasites (transmit human diseases)
- Include vital model organisms like fruit fly and Roundworm
What are the general characteristics of all protostomes?
- Bilaterally symmetric
- Tripoblastic
- Gastrula pore becomes mouth
What are the phyla included in Lophotrochozoa
- Rotifera
- Platyhelminthes
- Aneelida
- Mollusca
What are the phyla included in Ecdysozoa?
- Nematoda
- Tardigrada
- Onychophora
- Arthopoda
What are the three general characteristics of all lophotrochozoans
- Lophophore: structure used in suspension feeding
- Trochophore: Larvae with a ring of cilia used in locomotion and feeding
- Display spiral cleavage in embryo development
What is the defining characteristic in Rotifera
The presence of corona (cluster of cilia at their tail end) used for suspension feeding
Where do most rotifera live
Live in damp soils, marine and freshwater environments (Important component of plankton)
How can Rotiferas reproduce?
Usually through sexual reproduction
Can reproduce asexually through parthenogenesis
Parthenogenesis
When the unfertilized eggs via mitosis hatch into asexually produced offspring.
Characteristics of Platyhelminthes (flatworms)
- Can be free living or parasites
- Broad, flattened body; unsegmented
- Lack coelom, gas exchange structures and blood vessels
- Lack lophophore and digestive tract with only one opening for ingestion of food and elimination of wastes
Significance of the platyhelminthes (flatworms) flat body
Adaptation that provides large surface area for gas exchange
Characteristics of Annelida (Segmented Worms)
- Segmented body and a coelom
- Numerous bristle-like extensions called chaetae that extend from appendages called parapodia
What are endoparasites
Parasites that live in the tissues and organs of their hosts
What is a Mollusca (mollusk) and what are its characteristics
Phyla of Lophotrochozoans
- Foot: large muscle at the animal base used for movement
- Visceral mass: Most internal organs and external gill
- Mantle: Body wall that forms enclosure: where many species secretes calcium carbonate shells
What are Bivalves?
Species like clams, oysters, scallops, mussels that is part of the phylum Mollusca
What is the main characteristic of bivalves
A. Have a shell with two parts (valves)
1. Made of calcium carbonate
2. Hinged and closes using muscles attached to the valves
3. Protect animal from predation
B. Suspension feeders
C. Only mollusks without a radula
What are gastropods?
Species part of the Mollusca phyla that contain 70,000 marine snails, slugs, nudibranchs
Only mollusk group that transitioned from water to land
What are Chitons and its main characteristics?
Part of phyla Mollusca
- Have eight calcium carbonate plates along dorsal side that form protective shell
- Marine
- Use radula to scrape algae off rocks and move by gliding on the broad, muscular foot.
What are Cephalopods and its characteristics ?
Part of phyla Molluscs, ex octopuses and squids
- Have well-developed head
- Have foot modified to form long, muscular tentacles
- Except for nautilus, have highly reduced shells
- Most have large brains & sophisticated eyes
- Separate sexes
- Sexual reproduction and internal (male transfers spermatophore packet to female)
- Eggs develops directly into adults
- Contains Chromatophore
cells in skin that can rapidly change color for camouflage & communication
What is an Ecdysozoan and defining characteristics?
- Grow intermittently by molding
What is molting?
How ecdysozoans grow by shedding of soft cuticle or hard exoskeleton