Final Flashcards
Advantages and disadvantages of ocean life
Advantages: Stable temperatures Buoyancy provided Plentiful food and waste removal Fluid and salt gradients easily maintained
Disadvantages:
Currents - water movement
When and where animal life began
~540 million years ago (Precambrian)
First in shallow marine environments
Cambrian explosion
Disadvantages of life in fresh water
Variable:
Temperature
Turbidity - light
Volume
Less food
Hypotonic
Disadvantages of terrestrial
Desiccation
Larger temperature variability
Gametes and embryos need protection
Characteristics common to animals
Heterotrophic
Multicellular
Specialized cells without cell walls
Locomotion at some time
Nervous and muscular systems for rapid response to stimuli
Sexual reproduction w/ non motile egg and flagellated sperm
6 key transitions in animal body plans.
Evolution of
- Tissues
- Symmetry
- Body cavity
- Blastopore differentiation
- Skeletal support structures
- Segmentation
Table 32.1 - 32.4
Hetertrophy Multicellularity No cell walls Active movement Diversity in form Diversity in habitat Sexual reproduction Embryonic development Tissues
6 key transitions in body plans for animals
- Tissues
- Symmetry
- Body cavity
- Blastopore differentiation
- Skeletal support structures
- Segmentation
Parazoa
Asymmetrical sponges
Phylum Porifera
Multicellular Lack tissues Asymmetrical Noncoelomate Sessile
Choanocytes
Spongecoel
Osculum
Asco/syco/leuconoid bodies
Filter feeders
Intracellular digestion
Asexual fragmentation
Hermaphroditic
Phylum Cnidaria
Radial symmetry Acoelomate Specialized tissues Diploblastic Cnidocytes Extra cellular digestion
3 classes:
Anthozoa - Corals & Anemones
Hydrozoa - Hydra & man-o-war
Scyphozoa - Jellyfish
Characteristics of Lophotrochozoa
Lophophore
No molting
3 phyla: Platyhelminthes, Mollusca, Annelida
Characteristics of Ecdysozoa
Ecdysis - molting of cuticle
2 phyla: Arthropoda and Nematoda
Phylum Platyhelminthes
Flatworms Acoelomate Bilateral symmetry Cephalization Triploblastic Organs Many hermaphroditic Cuticles in parasites
3 classes:
Turbellaria - free-living flatworms
Trematoda - parasitic flukes
Cestoda - parasitic tapeworms
Class Turbellaria
Free-living flatworms Carnivorous Auricles Muscular pharynx Sexual hermaphroditism Asexual regeneration
Class Trematoda
Parasitic flukes
Hooks and suckers
Ecto/endoparasitism
Complex life cycle
Intermediate host
Dead end host
Swimmers itch
Class Cestoda
Parasitic tapeworms Sextoda Ribbon-like Scolex Proglottids
Phylum Nematoda
Round worms Nemo-round Pseudocoelomate Bilateral symmetry Triploblastic Cuticle Parasitic
Decomposers and predators of bacteria
Numerous in soil, fresh and salt water.
Phylum Mollusca
Soft body - Mollusca
Clams
Usually covered by shell
Lack segmentation
4 classes:
Gastropoda - snails
Bivalvia - mussels
Cephalopoda - octopus
Economically:
Food, mother of pearl, & zebra mussels
Class Bivalvia
"Two shells" Mussels Hinged 2-part shell Suspension feeders Spade-like foot
Class Gastropoda
"Stomach foot" Foot - locomotion Visceral mass - organs Mantle - secretes shell Shell - protection Eye stalks & tentacles Grazers Terrestrial
Class Cephalopoda
"Head foot" Squids Coiled, internal, or no shell Foot divided into tentacles Stream lined locomotion via siphons Chromatophores - cells w/ pigment granules Ink sac - carries ink Predators
Nutrition:
Carnivorous
Horny beak for tearing
Phylum Annelida
Segmented
Lophotrochozoa
Coelomates
Triploblastic
Repeated backup subunits
Setae - chitinous bristles
Diffusion
2 classes:
Polychaeta
Clitellata
Class Polychaeta
Parapodia w/ many setae Filter feeders or detritivores Sexual Dioecious External fertilization
Class Clitellata
Earthworms Detritivores Monoecious Sperm exchanged and stored Fertilization occurs externally in cocoon
Leeches Ectoparasitic Internal fertilization No septa; no setae Sucked Clitellum when breeding
Phylum Arthropoda
"Jointed foot" >1 million spp.; 80% of animals Most successful Segmented Armor like cuticle (exoskeleton)
2 classes:
Crustacea
Hexapoda
Chelicerata ~
Economic importance of Arthropoda
Compete with us for food
Pollination
Food source
Vector for disease
Class Crustacae
Lobsters "Swiss Army knife of animal world" 3 pair Mandibles Biraneas (2 branched) 2 pairs if antennae
Cephalothorax Abdomen Chelipads Swimmerets Walking legs
Class Hexapoda
Metamorphosis in insects Most successful class Minimized interspecific competition Simple vs Egg>nymph>adult Complete Egg>larva>pupa>adult
Phylum Echinodermata
“Spiny skin”
Pentaradial
Endoskeleton
Complete gut No brain Dioecious External fertilization Water vascular system
Class Astroidea
5 main clades and 9 phyla
Parazoa - Porifera Radiata - Cnidaria Lophotrochozoa - Platyhelminthes - Molluska - Annelida Ecdysozoa - Nematoda - Arthropoda Deuterstomia - Echinodermata - Chordata
Class Astroidea
Central disk
5x tapered arms
Important predators
1cm to 1m in size
Phylum Chordata
Triploblastic
Coelomates
Bilateral symmetry
Endoskeleton
4 critical innovations •Notochord •Dorsal hollow nerve cord •Pharyngeal slits •Post anal tail
4 critical innovations of Chordata
Notochord - dorsal rod
Nerve cord - electrochemi signals
Pharyngeal slits - food/gas
Post anal tail - appendage
Subphyla Urochordata
"Tail-cords" Invertebrates Tunicates Filter feeders; sessile adults Tunic of cellulose
Subphyla Cephalocordata
Lancelets "Head cords" Invertebrates Filter feeders Fish shaped Segmented
Craniates
Invertebrates
Cranium (brain case)
Neural crest - stem cells
Chordate evolution of
- Cranium
- Vertebrae
- Jaws
- Lungs
- Limbs
- Amniotic egg
Class Mixini
Hagfish
Invertebrates
Craniates*
Copious amounts of slime
Transitions from invertebrates to vertebrates
Notochord -> vertebral column
Nerve cord -> central nervous
Pharyngeal slits -> eustachian tube
Post anal tail -> terminal anus
Subphyla Vertebrata
Skeleton:
• Cranium
• Muscles attached to endoskeleton
Nervous:
• Neural crest cells
• pronounced cephalization
Nutrition:
• variable
• complete digestive system
Class Cephalospidomorphi
Lamprey Suction cup mouth No paired fins Parasites Vertebrate*
Class Chondricthyes
Cartilaginous fish - sharks, skates, rays Skeleton Vertebrate Paired fins Placoid scales (enamel and dentine) Sharks have teeth Jaws*
Bony fish
2 classes:
•Actinopterygii
•Sarcopterygii
Differences from Chondricthyes
•Bony skeleton
•Operculum
•Swim bladder
Class Actinopterygii
Ray-finned fish
Fins have thin, bony, flexible rays
Class Sarcopterygii
Lobe-finned fish
Lungfish
- 7 lobed fins
- lungs*
Tetrapod adaptations
Prevent desiccation Locomotion Protected reproduction Homologous structures Strengthened bones
Class Amphibia
Frogs, toads, etc
Double life - metamorphic Cutaneous respiration Lungs Limbs* 3 chambered heart Ectotherms External fertilization Larval aquatic
Amniotes
Amniotic egg during reproduction
Reptiles, aves, and mammals
Class Reptilia
Turtles Internal fertilization Amniotic egg Ectothermic Dry skin w/ horny scales Thoracic breathing (rib cage) Lungs with many chambers 3 chambered heart
Class Aves
Adaptations for powered flight
- feathers
- light hollow bones
- 4 chambered heart
- very efficient lungs
- endothermic
- high metabolic rate
- well developed nervous system
Class Mammalia
Adapted to cold Hair Mammary glands Specialized teeth Endotherms; homeostasis 4 chambered heart Highly developed nervous system Muscular diaphragm Thoracic breathing
Bell curve axi
X - variation
Y - frequency
5 Agents of evolution
Small pop. size/genetic drift No random mating Mutation Migration/gene flow Natural selection
Evidence for evolution
Fossil record Biogeography Homoplasy Artificial selection Homologies Evidence of adaptation
Natural selection needs
Variation of heritable traits
Overproduction
Limits on growth
Differential reproductive success
