Exam Review: Chordates and Tetrapods

amnion

A membrane that surrounds and protects the embryo in amniotic eggs.

chorion

The outermost membrane surrounding the embryo in amniotic eggs.

allantois

A membrane involved in waste storage and gas exchange in embryos.

cranium

The bony structure that encases and protects the brain.

vertebrae

The individual bones that make up the vertebral column or spine.

gnathostomes

Jawed vertebrates that include fish, amphibians, reptiles, birds, and mammals.

coelacanth

A rare deep-sea fish that was thought to be extinct and is a member of the lobe-finned fish group.

foramen ovale

An opening in the fetal heart that allows blood to bypass the lungs.

gestation

The period of development of an embryo or fetus inside the womb.

amniotic egg

An egg that contains a protective amniotic membrane, allowing for development in a terrestrial environment.

placenta

An organ that develops in the uterus during pregnancy to provide nutrients and oxygen to the fetus.

lactation

The process of producing milk in mammals to feed their young.

swim bladder

A gas-filled organ that helps fish maintain buoyancy in water.

lancelet

A small, fish-like marine animal that is a member of the subphylum Cephalochordata.

tunicate

A marine invertebrate animal that belongs to the subphylum Urochordata.

hagfish

A jawless fish known for its slime production and scavenging behavior.

lampreys

Jawless fish that are known for their parasitic behavior on other fish.

foramen magnum

The large opening at the base of the skull through which the spinal cord passes.

tetrapod

A vertebrate animal with four limbs, including amphibians, reptiles, birds, and mammals.

bipedalism

The ability to walk on two legs, a characteristic of humans and some other species.

diapsid

A group of reptiles characterized by having two temporal fenestrae in their skulls.

synapsid

A group of animals that includes mammals and their ancestors, characterized by a single temporal fenestra.

monotreme

A group of egg-laying mammals, such as the platypus and echidna.

marsupial

A group of mammals that give birth to underdeveloped young, which typically continue to develop in a pouch.

eutherian

A group of mammals known as placental mammals, which give birth to more fully developed young.

anthropoid

A group of primates that includes monkeys, apes, and humans.

hominins

The group of species that includes modern humans and their ancestors.

FOXP2 gene

A gene associated with speech and language development in humans.

NOVA1 gene

A gene implicated in the development of the nervous system and associated with language.

Chondrichthyes

A class of cartilaginous fish that includes sharks and rays.

Osteichthyes

A class of bony fish

Urodela

salamanders.

Anura

frogs and toads.

Apoda

caecilians.

oviparous

animals that lay eggs.

ovoviviparous

animals that produce eggs that hatch inside the body.

viviparous

animals that give birth to live young.

forebrain

complex behaviors, sensory processing, and voluntary movement.

midbrain

relay center for visual and auditory information.

hindbrain

controls basic life functions such as breathing and heart rate.

ectothermy

The condition of relying on external sources of body heat.

endothermy

The ability to maintain a constant body temperature through internal metabolic processes.

current day amniotes

lay eggs or give birth to live young.

prosimians

lemurs and tarsiers.

gracile australopithecines

A group of early hominins characterized by a lighter build.

robust australopithecines

A group of early hominins characterized by a heavier build.

unifying features of Chordates

a notochord and dorsal nerve cord.

basic body plan of cephalochordates

a notochord, dorsal nerve cord, and pharyngeal slits.

basic body plan of urochordates

a sac-like form and a notochord in the larval stage.

basic body plan of vertebrates

backbone, skull, and specialized organs.

derived characters of amniotes

amniotic egg.

derived characters of birds

Unique features of birds, such as feathers and hollow bones.

derived characters of mammals

Distinctive traits of mammals, including fur and mammary glands.

derived characters of primates

Traits that define primates, such as opposable thumbs and large brains.

derived characters of hominids

Characteristics that distinguish hominids from other primates, including bipedalism.

Out-of-Africa hypothesis

The theory that modern humans originated in Africa and migrated to other parts of the world.

Chordata subphyla

The major divisions within the phylum Chordata, including Cephalochordata and Urochordata.

Subphylum Vertebrata

The subphylum that includes all vertebrates, characterized by a backbone.

Class Amphibia

A class of animals that includes frogs, toads, and salamanders.

Class Mammalia

A class of animals characterized by mammary glands and hair.

Formation of simple inorganic compounds

Formation of simple inorganic compounds such as amino acids through abiotic processes.

Formation of organic macromolecules

Formation of organic macromolecules (polymers).

Packaging of organic molecules

Packaging of the organic molecules in a bilipid membrane that showed fission and probiont.

Evolution of autocatalytic molecules

Evolution of an autocatalytic molecule made up of RNA = ribozymes.