chordates and vertabrates

what phylum do all vertebrates belong to?

phylum chordata

what are the 5 key characteristics of all chordates (at some life stage)

notochord, dorsal hollow nerve chord, pharyngeal slits, post-anal tail, and endostyle/thyroid glans

what is the notochord?

a flexible rod for support, present in all chordates during development

what is the dorsal hollow nerve cord?

a nerve chord that runs along the back and becomes the brain/spinal cord

what are pharyngeal slits used for in aquatic chordates?

they function into filter-feeding or develop into gills

what are pharyngeal slits used for in terrestrial chordates?

they develop into parts of the ear, tonsils, and other structures

what is the post-anal tail?

a tail that extends beyond the anus, used for locomotion or balance

what is the endostyle?

a gland that produces mucus or develops into the thyroid gland

what is a vertebrate?

a chordate with a backbone made of vertebraew

what is the subphylum of vertebrates?

subphylum vertebrata (also called craniata)w

what major trait separates vertebrates from invertebrate chordates

the presence of a vertebral column

what are the two invertebrate chordates?

lancelets and tunicates

what do all vertebrates have in common in terms of organ systems?

complete digestive, circulatory, respiratory, excretory, and nervous systems

are vertebrates triploblastic?

yes, all vertebrates are triploblastic

are vertebrates deuterostomes or protostomes

deuterostomes

do all vertebrates have a coelom?

yes, they are all eucoelomates

what does “agnatha” mean?

no jaw

what are two modern jawless fish?

hagfish and lampreys

do jawless fish have vertebrae?

hagfish do not, lampreys have primitive vertebrae

do jawless fish have paired fins?

no, they lack paired fins

are jawless fish cartiloginous?

yes, they have a cartilaginous skeleton

what does gnathostome mean?

“jaw mouth” - vertebrates with jaws

what are teo important traits of gnathostomes?

hinged jaws and paired fins

what did hinged jaws allow gnathostomes to do?

actively fee, grasp, and tear food

what is class chonrichthyes?

cartilaginous fish like sharks, rays, and skates

what is class osteichthyes?

bony fish

do chonrichthyes have bones?

no, they have cartilage skeletons

what type of fertilization do chondrichthyes have?

internal fertilization

what are two features of bony fish?

bony skeleton and swim bladder

what is the function of the swim bladder?

controls buoyancy in the waterw

what type of fertilization do most bony fish use?

external fertilization

what does amphibian mean?

“double life” - aquatic larvae and terrestrial adults

what kind of skin do amphibians have?

moist and permeable skin for gas exchange

how do amphibians reproduce?

water-dependent, with external fertilizaton

do amphibians go through metamorphosis?

yes, most have a larval (tadpole) stage and undergo metamorphosis

what kind of circulatory system do amphibians have?

double loop with a 3-chambered heart (2 atria, 1 ventricle)