Bio unit test 2 Flashcards
(19 cards)
What is a Porifera and its characteristics?
It’s a sponge
- Sessile (don’t move), porous bodies
- Live in marine and freshwater
- No true tissues or organs
- Filter feeders (use water current to catch
food)
- Specialized cells: choanocytes
- Mostly hermaphrodites (both sexes in
one body)
What are Cnidarians and its characteristics?
Jellies/corals
- Radial symmetry, 2 layers (diploblastic), no brain
- One body opening = mouth and anus
- Two body forms: polyp (attached) and medusa (floating)
- Use tentacles with cnidocytes (stingers) to catch prey
- Classes: Hydrozoa, Scyphozoa, Cubozoa, Anthozoa
What are platyhelminthes and what are their characteristics?
Flatworms:
- Simple bilateral animals
- Acoelomates (no body cavity)
- Include flukes, tapeworms
- Simple nervous system and
protonephridia (early kidneys)
What are Nematoda and their characteristics?
Roundworms
- Pseudocoelomates (fluid-filled body cavity)
- Cylindrical body, no segmentation
- Have digestive and vascular system
What are the characteristics of Mollusks?
- Soft-bodied, often with shells
- No segmentation
- 3 body parts: foot, visceral mass, mantle
- Classes:
Gastropoda (snails, slugs)
Cephalopoda (octopus, squid)
Bivalvia (clams, oysters)
What are Annelids and their characteristics?
Segmented worms
- Coelomates, segmented body (rings)
- Classes:
Oligochaeta: earthworms
Polychaeta: marine worms with paddles
Hirudinea: leeches
What are arthropods and their characteristics?
- Most diverse animals
- Segmented, exoskeleton, jointed appendages
- Subphyla:
Chelicerata (spiders, scorpions,
horseshoe crabs)
Myriapoda (centipedes (chilopoda) & millipedes(diplopoda)
Hexapoda (insects – wings, 3-part body)
Crustacea (crabs, lobsters, shrimp)
What are Echinoderms and what’s their characteristics?
Sea stars, sea urchins
- Radial symmetry (adults), bilateral (larvae)
- Deuterostomes like chordates
- Water vascular system for movement
What traits do Chordates have?
- Notochord (long rod, skeletal support)
- Dorsal nerve cord
- Pharyngeal slits on the outside
- Post-anal tail
What are Craniates/Vertabrates’ characteristics?
- Craniates = chordates with a head
- Vertebrates = craniates with a backbone
- Earliest vertebrates: jawless fish (hagfish, lampreys)
What are Gnathostomes and their characteristics?
Vertabrates with jaws
- Jaws evolved from gill supports
- Include:
Chondrichthyans (sharks, rays – cartilage skeleton)
Osteichthyes (bony fish)
What are Bony Fish’s characteristics/types of fish?
- Ray-finned fish (Actinopterygii) – most common fish
- Lobe-finned fish (Sarcopterygii) – evolved into land animals
- Have swim bladder, scales, operculum (gill cover)
What are Tetrapds and their characteristics?
Four-imbed vertabrates
- Evolved from lobe-finned fish
- Adaptations: limbs, ears, lungs
- First group = amphibians
What are the characteristics of an amphibian?
- Live “two lives” (water & land)
- Moist skin for gas exchange
- Eggs laid in water
What are the propreties of Amniotes?
- Amniotic egg = protects embryo on land
- Adaptations: skin, rib-based breathing
What’s the propreties of a reptile?
- Scales, shelled eggs, internal fertilization
- Cold-blooded (ectothermic) – except birds!
Whats the propreties of birds?
- Evolved from dinosaurs
- Adaptations for flight:
- Wings, feathers, hollow bones
-Endothermic (warm-blooded) - Archaeopteryx: oldest bird, link between birds and reptiles
What makes a mammal a mammal?
- Traits: hair, mammary glands, warm-blooded, larger brains, heterodonts
- 3 types:
Monotremes (egg-layers like platypus)
Marsupials (pouch – kangaroo)
Eutherians (placental – humans, dogs)
What’s the characteristics of primates and humans?
Traits:
- Grasping hands/feet
- Forward-facing eyes
- Large brain
Humans:
- upright posture
- Have language, tools, symbolic thought
