GPT BIO EXAM 5

Animal characteristics

Multicellular eukaryotes without cell walls that are chemoheterotrophs and usually motile

Parazoa

Animals without true tissues (sponges)

Eumetazoa

Animals with true tissues

Ectoderm

Embryonic layer that forms skin and nervous system

Endoderm

Embryonic layer that forms gut lining

Mesoderm

Embryonic layer that forms muscles and internal organs

Diploblastic

Organism with two germ layers (ectoderm and endoderm)

Triploblastic

Organism with three germ layers (ectoderm, mesoderm, endoderm)

Blastula

Hollow ball of cells formed early in development

Gastrula

Stage where embryonic layers form and gut begins

Blastopore

Opening that becomes mouth or anus

Radial symmetry

Body plan with multiple planes of symmetry

Bilateral symmetry

Body plan with one plane of symmetry and cephalization

Cephalization

Concentration of sensory organs at the head

Acoelomate

No body cavity

Pseudocoelomate

Body cavity not fully lined with mesoderm

Coelomate

True body cavity fully lined with mesoderm

Protostome

Blastopore becomes mouth; spiral, determinate cleavage

Deuterostome

Blastopore becomes anus; radial, indeterminate cleavage

Spiral cleavage

Cells divide at angles (protostomes)

Radial cleavage

Cells divide parallel/perpendicular (deuterostomes)

Determinant cleavage

Cell fate determined early

Indeterminate cleavage

Cells retain ability to develop into full organism

Lophotrochozoa

Protostomes with lophophore or trochophore larva

Ecdysozoa

Protostomes that molt (ecdysis)

Ecdysis

Molting of exoskeleton

Platyhelminthes

Flatworms; acoelomates with no complete gut

Annelida

Segmented worms with coelom and closed circulatory system

Mollusca

Animals with foot, mantle, and visceral mass

Radula

Scraping feeding structure in molluscs

Gastropoda

Snails and slugs; most diverse molluscs

Bivalvia

Clams and oysters; filter feeders with no head

Cephalopoda

Squid and octopus; advanced predators

Nematoda

Roundworms; pseudocoelomates with cuticle

Arthropoda

Invertebrates with exoskeleton and jointed appendages

Exoskeleton

Hard external covering for support and protection

Crustacea

Arthropods like crabs and shrimp

Arachnida

Spiders and ticks; two body regions, no antennae

Insecta

Arthropods with 3 body parts and 6 legs

Complete metamorphosis

Egg → larva → pupa → adult

Incomplete metamorphosis

Egg → nymph → adult

No metamorphosis

Egg → young → adult

Echinodermata

Deuterostomes with radial adults and water vascular system

Water vascular system

Fluid system used for movement and feeding in echinoderms

Chordate

Four traits: notochord, nerve cord, pharyngeal slits, post-anal tail

Notochord

Flexible support structure in chordates

Dorsal hollow nerve cord

Develops into central nervous system

Pharyngeal slits

Openings used for feeding or respiration

Post-anal tail

Tail extending beyond anus

Cephalochordata

Lancelets; retain chordate traits as adults

Urochordata

Tunicates; chordate traits only in larvae

Vertebrata

Chordates with vertebrae (backbone)

Vertebrae

Evolutionary step separating vertebrates from chordates

Jaws

Evolutionary step separating jawless and jawed vertebrates

Gnathostomes

Jawed vertebrates

Agnatha

Jawless vertebrates (hagfish, lampreys)

Lungs

Adaptation for breathing air

Lobed fins

Fins that led to movement onto land

Tetrapods

Vertebrates with four limbs

Amniotic egg

Egg with membranes allowing reproduction on land

Amnion

Protective fluid-filled membrane

Yolk sac

Nutrient supply for embryo

Chorion

Gas exchange membrane

Allantois

Waste storage membrane

Amniotes

Reptiles, birds, and mammals

Lactation

Milk production in mammals

Chondrichthyes

Cartilaginous fish (sharks, rays)

Actinopterygii

Ray-finned fish with operculum and swim bladder

Operculum

Bony flap covering fish gills

Swim bladder

Organ for buoyancy control

Amphibia

Vertebrates with aquatic larvae and terrestrial adults

Reptilia

Ectothermic amniotes with scales

Aves

Birds; endothermic with feathers and hollow bones

Mammalia

Endothermic vertebrates with hair and milk

Mammal characteristics

Hair, milk, endothermy, 4-chambered heart

Monotremes

Egg-laying mammals (platypus, echidna)

Marsupials

Mammals with pouch development

Eutherians

Placental mammals with long gestation

Heterodont dentition

Different types of teeth

Incisors

Cutting teeth

Canines

Tearing teeth

Premolars

Crushing teeth

Molars

Grinding teeth

Homodont dentition

All teeth are similar (whales)

Panniculus adiposus

Fat layer for insulation

Sexual dimorphism

Differences between males and females

Rodentia

Mammals with continuously growing incisors

Chiroptera

Bats; only flying mammals

Artiodactyla

Even-toed ungulates (deer, cows)

Carnivora

Mammals with carnassial teeth for cutting

Carnassial teeth

Specialized cutting teeth

Primates

Mammals with large brains and opposable thumbs

Primates

Order divided into prosimians and anthropoids