Ch.33 - Invertebrates Flashcards
(45 cards)
Invertebrates lack a backbone and comprise __% of all animal species.
Invertebrates lack a backbone and comprise 95% of all animal species.
Sponges are members of wh phylum
Porifera
Describe sponges in terms of habitat, tissue-composition, food sources.
Sedimentary, often mistaken for plants
Live in fresh and marine waters
Lack true tissues, but have many cell types
Suspension (filter) feeders
- capture food particles suspended in the water that passes thru their body
The _______ is the central cavity in sponges, where water enters thru pores and leaves thru an opening called the _______.
The spongocoel is the central cavity in sponges, where water enters thru pores and leaves thru an opening called the osculum.
_________ are flagellated collar cells that line interior of spongocoel.
Choanocytes are flagellated collar cells that line interior of spongocoel.
- Generate water current thru the sponge, ingest suspended food.
- Remarkably similar to choanoflagellate protists.
Sponges consist of a gelatinous noncellular _______ layer b/w two cell layers.
Sponges consist of a gelatinous noncellular mesohyl layer b/w two cell layers.
_________ are totipotent cells found in the mesohyl of sponges that play roles in digestion and manufacture of skeletal fibers
Amoebocytes are totipotent cells found in the mesohyl of sponges that play roles in digestion and manufacture of skeletal fibers
T/F: most sponges are hermaphrodites
TRUE
fxn as both male and female
typ sequential hermaphroditism, i.e. fxn first as one sex, then the other
Name a few species in the phylum Cnidaria
Jellies, corals, hydras
Sea wasps
Sea anemone
colonial polyps
Cnidarians have a relatively simple diploblastic, radial body plan and contain a sac w a central digestive compartment, called the ________.
Cnidarians have a relatively simple diploblastic, radial body plan and contain a sac w a central digestive compartment, called the gastrovascular cavity.
- I.e. single opening as mouth & anus
Two variations of Cnidarian body plans:
- A ______ adheres to the substrate by the aboral end of its body (sessile)
- A ______ has a bell-shaped body with its mouth on the underside (mobile)
Two variations of Cnidarian body plans:
- A polyp adheres to the substrate by the aboral end of its body (sessile)
- A medusa has a bell-shaped body with its mouth on the underside (mobile)
W/i the Cnidaria phylum, the clade ________ incl corals and anemones.
W/i the Cnidaria phylum, the clade Anthozoa incl corals and anemones.
- Occur ONLY as polyps.
_____ often form symbioses w algae and secrete a hard exoskeleton.
Corals (Cnidaria; Anthozoa) often form symbioses w algae and secrete a hard exoskeleton.
Ea gen grows on the skeletal remains of the prev gen, forming “rocks” that provide habitat for other species
Bilaterian animals have which type of symmetry and tri- or diploblastic dev?
Bilaterian animals have bilateral symmetry and triploblastic dev.
- Most have a coelom and a digestive tract with TWO openings
The clade bilateria incl wh three clades?
Lophotrochozoa
Ecdysozoa
Deuterostomia
Phlyum Mollusca belong to wh clade?
Lophotrochozoa
- Incl snails and slugs; oysters and clams; octopuses and squids
- Soft-bodied, but typ protected by a calcium carbonate shell
Phylum Annelids belong to wh clade?
Lophotrochozoa
Bodies composed of a series of fused rings
Three classes:
- Oligochaeta (earthworms and their relatives)
- Polychaeta (polychaetes)
- Hirudinea (leeches)
what are oligochaetes
class w/i phylum annelids, w/i clade Lophotrochozoa
Incl earthworms
Chaetae: bristles made of chitin
- Oligo = few, thus fewer chaetae than other classes of annelids
T/F: earthworms are hermaphrodites
TRUE
earthworms are simult hermaphrodites, but cross-fertilize
___________ is a group of protostome animals, including Arthropoda, Nematoda, and several smaller phyla.
Ecdysozoa is a group of protostome animals, including Arthropoda, Nematoda, and several smaller phyla.
Which animal group contains the most species?
Ecdysozoa
Contains phyla Arthropoda and Nematoda
What feature distinguishes Ecdysozoans?
Cuticle: tough external coat
Ecdysis: process by which the cuticle is shed or molted
Which phylum comprises 2/3 of all known animal species?
Arthropods comprise 2/3 of all known animal species
> 1 mil
The Arthropod body plan dates back to which distinct time period?
The Arthropod body plan dates back to the Cambrian explosion
Segmented body
Tough exoskeleton (cuticle)
Jointed appendages
