bio112 exam5

General Characteristics

Exclusively marine; adults show radial symmetry; larvae bilateral symmetry; triploblastic; true coelom; tube feet; water vascular system; deuterostomes; skin covered in CaCO₃ plates; “spiny skin”

Endoskeleton

Epidermis covers skeleton; CaCO₃ plates connected by ossicles; porous endoskeleton

Water vascular system

Hydraulic system used for locomotion and feeding; water enters through madreporite; ring canal distributes water; tube feet regulate movement

Digestive system (Echinoderms)

Complete digestive system; mouth on oral side; anus on aboral side; some species evert stomach into prey

Nervous system (Echinoderms)

Nerve ring with radial nerves extending down each arm

Reproduction (Echinoderms)

Sexual reproduction with separate sexes; mostly external fertilization; some fragmentation/regeneration

Class Crinoidea

Sea lilies and feather stars; sessile or free-swimming; feather-like appearance; filter feeders

Class Asteroidea

Sea stars; arms merge with central disc; carnivorous; can regenerate arms

Class Ophiuroidea

Brittle stars; highly mobile; tube feet lack suckers; central disc distinct from arms

Class Echinoidea

Sea urchins and sand dollars; tube feet in rows; Aristotle’s lantern present

Class Holothuroidea

Sea cucumbers; leathery skin; elongated body; tentacles around mouth

General Characteristics (Chordata)

Triploblastic; deuterostomes; bilateral symmetry; occupy most habitats; highly advanced

Notochord

Flexible supporting rod present during development; replaced by vertebral column in vertebrates

Nerve cord

Hollow dorsal nerve cord protected by vertebrae

Pharyngeal slits

Openings in pharynx used in filter feeding and respiration

Postanal tail

Tail extending beyond anus used for movement and muscle attachment

Advanced systems (Chordata)

Complete digestive system; closed circulatory system; ventral heart; endoskeleton; cephalization

Subphylum Urochordata

Tunicates/sea squirts; larvae resemble chordates; adults sessile; filter feeders

Subphylum Cephalochordata

Lancelets; retain all chordate traits as adults; filter feeders

Subphylum Vertebrata

Vertebral column encloses nerve cord; cranium protects brain

Fins

Used for stabilization and movement; paired fins are pectoral and pelvic; unpaired fins are dorsal

Tail types

Heterocercal and homocercal tails

Epidermal scales

Placoid; cycloid; ctenoid; ganoid

Swim bladder

Organ controlling buoyancy

Lateral line

Detects changes in water flow

Respiration (Fish)

Gills with countercurrent exchange

Circulation (Fish)

Two-chambered heart with single circulation

Metabolism (Fish)

Ectothermic

Skeleton (Fish)

Made of cartilage or bone

Reproduction (Fish)

External fertilization common; oviparous

Class Agnatha

Jawless fish including lampreys and hagfish; no paired fins

Class Chondrichthyes

Sharks

Class Osteichthyes

Bony fish with swim bladder and operculum

Class Amphibia

Amphibians with aquatic larvae and terrestrial adults

Double life

Aquatic larval stage and terrestrial adult stage

Skin adaptations (Amphibians)

Thin moist skin with poison glands

Tympanic membrane

Structure used for hearing

Metamorphosis

Tadpole transforms into adult

Tetrapods

Four-limbed vertebrates

Respiration (Amphibians)

Larvae use gills; adults use lungs and skin

Circulation (Amphibians)

Three-chambered heart

Metabolism (Amphibians)

Ectothermic

Hibernation

Winter dormancy

Estivation

Summer dormancy

Amplexus

Male grasps female during reproduction

Vocalizations (Amphibians)

Used to attract mates

Order Anura

Frogs and toads; tailless adults with long hind legs

Order Caudata

Salamanders and newts; retain tails

Order Gymnophiona

Caecilians; legless burrowing amphibians

Class Reptilia

Reptiles adapted for terrestrial life

Amniotic egg

Shelled egg allowing reproduction away from water

Skin (Reptiles)

Dry scaly keratinized skin

Structural adaptations (Reptiles)

Strong skeleton and claws

Sensory (Reptiles)

Good vision and smell; Jacobson’s organ in some

Respiration (Reptiles)

Lungs only

Circulation (Reptiles)

Usually three-chambered heart; crocodilians have four chambers

Metabolism (Reptiles)

Ectothermic

Reproduction (Reptiles)

Internal fertilization; mostly oviparous

Order Testudines

Turtles and tortoises with shells

Order Squamata

Lizards and snakes; largest reptile order

Order Crocodylia

Crocodiles and alligators

Order Sphenodonta

Tuatara found in New Zealand

Birds – Class Reptilia

Endothermic vertebrates with feathers and adaptations for flight

Feathers

Used for flight and insulation

Structural adaptations (Birds)

Hollow bones; keeled sternum; wings

Sensory (Birds)

Excellent vision

Respiration (Birds)

Air sacs with one-way airflow

Circulation (Birds)

Four-chambered heart

Metabolism (Birds)

Endothermic

Reproduction (Birds)

Hard-shelled eggs and internal fertilization

Infraclass Eoaves

Flightless birds

Infraclass Neoaves

Flying birds

Class Mammalia

Mammals with hair and mammary glands

Hair

Used for insulation and sensory functions

Glands (Mammals)

Sweat glands

Structural adaptations (Mammals)

Heterodont teeth and diaphragm

Sensory (Mammals)

Highly developed brain and external ears

Respiration (Mammals)

Lungs with alveoli

Circulation (Mammals)

Four-chambered heart

Metabolism (Mammals)

Endothermic

Reproduction (Mammals)

Internal fertilization; mostly viviparous

Subclass Prototheria

Monotremes such as platypus and echidna; egg-laying mammals

Infraclass Metatheria

Marsupials/pouched mammals

Infraclass Eutheria

Placental mammals including humans

Population

Group of organisms of the same species occupying a particular space

Population size

Number of individuals contributing to the gene pool

Crude density

Number of individuals per total area

Ecological density

Number of individuals per preferred habitat

Spatial dispersion

Amount of space between individuals

Clumped dispersion

Individuals occur in groups around resources

Uniform dispersion

Individuals evenly spaced due to territoriality/competition

Random dispersion

No apparent order or spacing

Temporal dispersion

Dispersion through time such as seasonal or daily

Movement

Encourages gene flow and increases fitness

Emigration

Permanent movement out of a population

Immigration

Permanent movement into a population

Migration

Temporary movement often seasonal or annual

Population demography

Population statistics and characteristics

Age structure

Distribution of ages in a population

Age pyramids

Graphs showing age distribution in a population