exam 4 BIOL 1202

tunicate

A member of the clade Urochordata, sessile marine chordates that lack a backbone

placenta

A structure in the uterus of a pregnant eutherian mammal that nourishes the fetus with the mother’s blood supply; formed from the uterine lining and embryonic membranes

reptile

A member of the clade of amniotes that includes tuataras, lizards, snakes, turtles, crocodilians, and birds

ovoviviparous

reffering to a type of development in which young hatch from eggs that are retained in the mother’s uterus

dinosaur

A member of an extremely diverse clade of reptiles varying in body shape, size, and habitat. Birds are the only extant dinosaurs

vertebrate

A chordate animal with vertebrae, the series of bones that make up the backbone

placoderm

A member of an extinct group of fishlike vertebrates that had jaws and were enclosed in a tough outer armor

amphibian

A member of the clade of tetrapods that includes salamanders, frogs, and caecilians .

swim bladder

In aquatic osteichthyans, an air sac that enables the animal to control its buoyancy in the water . (2 Words)

chondrichthyan

A member of the clade Chondrichthyes, vertebrates with skeletons made mostly of cartilage, such as sharks and rays

gnathostome

Member of one of the two main clades of vertebrates; gnathostomes have jaws and include sharks and rays, ray-finned fishes, coelacanths, lungfishes, amphibians, reptiles, and mammals

monotreme

An egg-laying mammal, such as a platypus or echidna. Like all mammals, monotremes have hair and produce milk, but they lack nipples

hominin

A group consisting of humans and the extinct species that are more closely related to us than to chimpanzees .

pharyngeal slit

In chordate embryos, one of the slits that form from the pharyngeal clefts and open into the pharynx, later developing into gill slits in many vertebrates .

ratite

A member of the group of flightless birds

paleoanthropology

The study of human origins and evolution .

acanthodian

Any of a group of ancient jawed aquatic vertebrates from the Silurian and Devonian periods

eutherian

Placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the mother by the placenta .

hagfish

Marine jawless vertebrates that have highly reduced vertebrae and a skull made of cartilage; most hagfishes are bottom-dwelling scavengers

oviparous

Referring to a type of development in which young hatch from eggs laid outside the mother’s body

cyclostome

Member of one of the two main clades of vertebrates; cyclostomes lack jaws and include lampreys and hagfishes. See also gnathostome

diapsid

A member of an amniote clade distinguished by a pair of holes on each side of the skull. Diapsids include the lepidosaurs and archosaurs .

lamprey

Any of the jawless vertebrates with highly reduced vertebrae that live in freshwater and marine environments. Almost half of extant lamprey species are parasites that feed by clamping their round, jawless mouth onto the flank of a live fish; nonparasitic lampreys are suspension feeders that feed only as larvae .

archosaur

A member of the reptilian group that includes crocodiles, alligators and dinosaurs, including birds

theropod

A member of a group of dinosaurs that were bipedal carnivores .

ray finned fish

A member of the clade Actinopterygii, aquatic osteichthyans with fins supported by long, flexible rays, including tuna, bass, and herring .

pterosaur

Winged reptile that lived during the Mesozoic era .

cloaca

A common opening for the digestive, urinary, and reproductive tracts found in many nonmammalian vertebrates but in few mammals .

chordate

A member of the phylum Chordata, animals that at some point during their development have a notochord; a dorsal, hollow nerve cord; pharyngeal slits or clefts; and a muscular, post-anal tail

opposable thumb

A thumb that can touch the ventral surface (fingerprint side) of the fingertip of all four fingers of the same hand with its own ventral surface .

notochord

A longitudinal, flexible rod made of tightly packed mesodermal cells that runs along the anterior-posterior axis of a chordate in the dorsal part of the body .

neural crest

In vertebrates, a region located along the sides of the neural tube where it pinches off from the ectoderm. Neural crest cells migrate to various parts of the embryo and form pigment cells in the skin and parts of the skull, teeth, adrenal glands, and peripheral nervous system .

synapsid

A member of an amniote clade distinguished by a single hole on each side of the skull. Synapsids include the mammals .

lobe fin

Member of a clade of osteichthyans having rod-shaped muscular fins. The group includes coelacanths, lungfishes, and tetrapods . (

lancelet

A member of the clade Cephalochordata, small blade-shaped marine chordates that lack a backbone .

pharyngeal cleft

In chordate embryos, one of the grooves that separate a series of arches along the outer surface of the pharynx and may develop into a pharyngeal slit .

tetrapod

A vertebrate clade whose members have limbs with digits. Tetrapods include mammals, amphibians, and birds and other reptiles

lepidosaur

A member of the reptilian group that includes lizards, snakes, and two species of New Zealand animals called tuataras .

osteichthyan

A member of a vertebrate clade with jaws and mostly bony skeletons .

endothermic

Referring to organisms that are warmed by heat generated by their own metabolism. This heat usually maintains a relatively stable body temperature higher than that of the external environment .

ectothermic

Referring to organisms for which external sources provide most of the heat for temperature regulation .

operculum

In aquatic osteichthyans, a protective bony flap that covers and protects the gills .

amniotic egg

An egg that contains specialized membranes that function in protection, nourishment, and gas exchange. The amniotic egg was a major evolutionary innovation, allowing embryos to develop on land in a fluid-filled sac, thus reducing the dependence of tetrapods on water for reproduction .

anthropoid

A member of a primate group made up of the monkeys and the apes (gibbons, orangutans, gorillas, chimpanzees, bonobos, and humans) .

marsupial

A mammal, such as a koala, kangaroo, or opossum, whose young complete their embryonic development inside a maternal pouch called the marsupium .

conodont

An early, soft-bodied vertebrate with prominent eyes and dental elements .

viviparous

Referring to a type of development in which the young are born alive after having been nourished in the uterus by blood from the placenta .

stimulus

In feedback regulation, a fluctuation in a variable that triggers a response

physiology

The processes and functions of an organism

endocrine system

In animals, the internal system of communication involving hormones, the ductless glands that secrete hormones, and the molecular receptors on or in target cells that respond to hormones; functions in concert with the nervous system to effect internal regulation and maintain homeostasis .

hormone

In multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the organism, changing the target cells’ functioning .

connective tissue

Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix . (

standard metabolic rate

Metabolic rate of a resting, fasting, and nonstressed ectotherm at a particular temperature .

hibernation

A long-term physiological state in which metabolism decreases, the heart and respiratory system slow down, and body temperature is maintained at a lower level than normal .

neuron

A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane .

thermoregulation

The maintenance of internal body temperature within a tolerable range

skeletal muscle

A type of striated muscle that is generally responsible for the voluntary movements of the body .

epithelial tissue

Sheets of tightly packed cells that line organs and body cavities as well as external surfaces .

acclimatization

Physiological adjustment to a change in an environmental factor

epithelium

An epithelial tissue .

regulator

An animal for which mechanisms of homeostasis moderate internal changes in a particular variable in the face of external fluctuation of that variable .

conformer

An animal for which an internal condition conforms to (changes in accordance with) changes in an environmental variable

nervous system

In animals, the fast-acting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with the endocrine system to effect internal regulation and maintain homeostasis .

homeostasis

The steadystate physiological condition of the body .

organ

A specialized center of body function composed of several different types of tissues

sensor

In homeostasis, a receptor that detects a stimulus .

fibroblast

A type of cell in loose connective tissue that secretes the protein ingredients of the extracellular fibers

integumentary system

The outer covering of a mammal’s body, including skin, hair, and nails, claws, or hooves .

torpor

A physiological state in which activity is low and metabolism decreases .

basal metabolic rate

The metabolic rate of a resting, fasting, and nonstressed endotherm at a comfortable temperature .

organ system

A group of organs that work together in performing vital body functions .

response

In cellular communication, the change in a specific cellular activity brought about by a transduced signal from outside the cell; or in feedback regulation, a physiological activity triggered by a change in a variable

counter current exchange

The exchange of a substance or heat between two fluids flowing in opposite directions. For example, blood in a fish gill flows in the opposite direction of water passing over the gill, maximizing diffusion of oxygen into and carbon dioxide out of the blood

interstitial fluid

The fluid filling the spaces between cells in most animals . (

set point

In homeostasis in animals, a value maintained for a particular variable, such as body temperature or solute concentration .

hypothalamus

The ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary .

negative feedback

A form of regulation in which accumulation of an end product of a process slows the process; in physiology, a primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change . (

positive feedback

A form of regulation in which an end product of a process speeds up that process; in physiology, a control mechanism in which a change in a variable triggers a response that reinforces or amplifies the change .

bioenergetics

The overall flow and transformation of energy in an organism; or the study of how energy flows through organisms .

smooth muscle

A type of muscle lacking the striations of skeletal and cardiac muscle because of the uniform distribution of myosin filaments in the cells; responsible for involuntary body activities .

muscle tissue

Tissue consisting of long muscle cells that can contract, either on its own or when stimulated by nerve impulses .

circadian rhythm

A physiological cycle of about 24 hours that persists even in the absence of external cues .

tissue

An integrated group of cells with a common structure, function, or both

blood

A connective tissue with a fluid matrix called plasma in which red blood cells, white blood cells, and cell fragments called platelets are suspended

cardiac muscle

A type of striated muscle that forms the contractile wall of the heart. Its cells are joined by intercalated disks that relay the electrical signals underlying each heartbeat .

macrophage

A phagocytic cell present in many tissues that functions in innate immunity by destroying microbes and in acquired immunity as an antigenpresenting cell .

bone

A connective tissue consisting of living cells held in a rigid matrix of collagen fibers embedded in calcium salts .

anatomy

The structure of an organism

glia

Cells of the nervous system that support, regulate, and augment the functions of neurons

glucagon

A hormone secreted by the pancreas that raises blood glucose levels . It promotes glycogen breakdown and release of glucose by the liver .

chylomicron

A lipid transport globule composed of fats mixed with cholesterol and coated with proteins .

appendix

A small, finger-like extension of the vertebrate cecum; contains a mass of white blood cells that contribute to immunity .

villus

A finger-like projection of the inner surface of the small intestine; or a finger-like projection of the chorion of the mammalian placenta. Large numbers of villi increase the surface areas of these organs .

rectum

The terminal portion of the large intestine, where the feces are stored prior to elimination

cecum

The blind pouch forming one branch of the large intestine .

insulin

A hormone secreted by pancreatic beta cells that lowers blood glucose levels. It promotes the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver and also stimulates protein and fat synthesis

microbiome

The collection of microorganisms living in or on an organism’s body, along with their genetic material .

gastric juice

A digestive fluid secreted by the stomach

pharynx

An area in the vertebrate throat where air and food passages cross; or in flatworms, the muscular tube that protrudes from the ventral side of the worm and ends in the mouth

absorption

The third stage of food processing in animals, the uptake of small nutrient molecules by an organism’s body .