chap 33 Flashcards
(41 cards)
phylogenetic relationships among major animal groups
Protist relative:
choanoflagellates
Metazoa:
Porifera: multicellularity
- Sponges
Eumetazoa (true animals):
- Tissue/cell specialization
Cnidarians: radial symmetry, diploblastic
- Jellyfish, coral, sea anemone
Bilateria: bilateral symmetry, triploblastic
Bilateria:
Protostomes: spiral and determinate cleavage, mouth first
Deuterostomes: radial and indeterminate cleavage, mouth second
Protostomes:
Lophotrochozoan: trochophore larva (band of cilia) and/or lophophore (crown on tentacles)
- Platyhelminthes
- Mollusca
- Annelida
Ecdysozoa: exoskeleton/cuticle, ecdysis (molting)
- Nematoda
- Arthropoda
Deuterostomes:
Deuterostomia: endoskeleton
- Echinodermata
- Chordata
morphological and functional characteristics of Porifera
5
- no symmetry
- multicellular
- no tissues
- filter feeders (improve water balance)
- asexual and sexual rep
morphological and functional characteristics of Cnidaria
7
-tissues
-Radial symmetry
-diploblastic
-Medusa moves freely in water (not all have this stage)
-Polyp is adhered to a substrate and sessile (except for portuguese man-o-war [hydrozoa])
- simple nervous system
- gastrovascular cavity digestion (mouth -> anus)
morphological and functional characteristics of Platyheminthes
6
-Flat bodied with high SA –> perform gas exchange via their skin.
- bilateral symmetry
- protostome
-Triploblastic
- no circulatory or respiratory system
- acoelomates (no true body cavity)
Ecological role:
Parasitic (worthless)
morphological and functional characteristics of Mollusca
7
- All are soft-bodied
- body div into 3 - mass, foot, and mantle (secretes shells)
- tissues
- bilateral symmetry
- trochophore
- muscular foot
- open circulatory sys exp for cephalopods
morphological and functional characteristics of Annelida
6
-Segmented worms
-Closed circulatory system
-eucoelomates (coelom is surrounded by the mesoderm)
- tissues
- bilateral symmetry
- trochophore
earthworms
morphological and functional characteristics of Nematoda
8
-Lack a circulatory system
- pseudocoelom – SPECIFIC TO THEM
-Play an important role in decomposition and nutrient cycling
- all habitats
-Parasitic and free-living
-ecdysis
-protostome
-bilateral symmetry
roundworm
morphological and functional characteristics of Arthropoda
6
- Segmented bodies, exoskeleton
- Covered by cuticle – prevent desiccation
- Many have open circulatory system
- have specialized areas on their body for gas exchange
- bilateral symmetry
- protostome
morphological and functional characteristics of Echinodermata
5
-Bilateral in larvae; radial in most adults
-Water-vascular system (derived from coelom; functions in movement, gas exchange, and feeding)
-No cephalization
-Thin epidermis covers hard endoskeleton
-deuterostome
morphological and functional characteristics of Chordata
6
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal slits
- Post-anal tail
- deutrostome
- -endoskeleton
Describe the characteristics of Cnidaria’s hydrozoa
Alternate between polyp and medusa phases
Describe the characteristics of Cnidaria’s scyphozoa
Spend majority of their life cycle in the medusa stage, sometimes lacking a polyp stage altogether
jellyfishes
Describe the characteristics of Cnidaria’s anthozoa
-Sea anemones and corals
-Completely lack a medusa stage
-Skeletons made of calcium carbonate
Describe the characteristics of Mollusca’s gastropoda
4
-Most living molluscs are these
-Most have a spiraled shell
-Use radula to graze on plants or bore holes on shells
-Gas exchange across their mantle cavity
snail & slugs
Describe the characteristics of Mollusca’s bivalva
4
-All aquatic
-Have gills
-Most are suspension feeders (cilia bring food from mucus of gills to stomach
-Can move with foot, or by flapping shells, but usually sessile
Describe the characteristics of Mollusca’s cephalopoda
6
-Marine predators
-Have beaks
-Foot is modified to a siphon and part of the tentacles
-Highly reduced internal shell
-Only mollusc with closed circulatory system
-Usually well developed sense organs and brain
Describe the characteristics of Arthropoda’s hexapoda
4
-Six-legged
-Wings crucial to success
-Extremely diverse (number, species, habitat)
-Are responsible for the spread of many diseases
Describe the characteristics of Arthropoda’s crustacea
3
-Cephalothorax and abdomen
-4 pairs of walking legs
-2 antennaes
Describe the characteristics of Arthropoda’s chelicerata
4
-2 pairs of antennae
-Fused cephalothorax
-Cuticle often hardened with calcium carbonate
-Gas exchanged through thin layers in cuticle, or in larger species, gills
spiders
Describe the characteristics of Echinodermata’s asteroidea
2
-Tube feet moves the star
-Multiple arms
sea stars
Describe the characteristics of Echinodermata’s ophiuroidea
3
-Central disk is distinct
-Tube feet reduced
-Use arms to move
brittle stars
Describe the characteristics of Echinodermata’s echinoidea
1
- spines/endoskeleton
sea urchins & sand dollars
Describe the characteristics of Echinodermata’s holothuroidea
4
-Reduced endoskeleton
-Lack spines
-Can throw up guts to distract predators
-Filter feeds
sea cucumbers
Describe the characteristics of Chordata’s cephalochordata
2
-Gas exchange across body; filter feed
-have all of the chordata’s characteristics
lancelets (saw it through a microscope)
