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125 terms

Biology Test 4

Buettners Bio 1407 Test IV
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Cleavage
A succession of mitotic cell divisions without cell growth between the divisions.
Blastula
Cleavage leads to this multicellular stage, which in many animals takes the form of a hollow ball.
Gastrulation
Process during which the layers of embryonic tissues that will develop into adult body parts are produced.
Gastrula
Resulting developmental stage of gastrulation.
Larva
Sexually immature form of an animal that is morphologically distinct from the adult, usually eating different food and even living in a different habitat than the adult.
Metamorphosis
A developmental transformation that turns the animal into a juvenile that resembles an adult, but is not yet sexually mature.
Ediacaran biota
Fossils of soft-bodied Eukaryotes, named for the Ediacara Hills of Australia.
Cambrian Explosion
A wave of animal diversification that occurred 535-525 million years ago, during the Cambrian period of the Paleozoic era.
Body Plan
Particular set of morphological and developmental traits, integrated into a functional whole- the living animal.
Radial Symmetry
Type of symmetry found in a flowerpot.
Ex: Sea Anemone
Bilateral Symmetry
Two-sided symmetry
Ex: Lobsters
Dorsal Side
Top side
Ventral Side
Bottom Side
Anterior End
Front end
Posterior End
Back end
Cephalization
Evolutionary trend in whih sensory equipment is concentrated at the anterior end, including a central nervous system ("brain") in the head.
Ectoderm
The germ layer covering the surface of the embryo, gives rise to the outer covering of the animal and, in some phyla, to the central nervous system.
Endoderm
The innermost germ layer, lines the pouch that forms during gastrulation (the archenteron) and gives rise to the lining of the digestive tract (or cavity) and organs such as the liver and lungs of vertebrates.
diploblastic
Animals that have only two germ layers.
Mesoderm
Layer present in all bilaterally symmetrical animals, which fills much of the space between the ectoderm and the endoderm.
Triploblastic
Having three germ layers.
Body Cavity
A fluid or air-filled pace between the digestive tract and the outer body wall found in most triploblastic animals.
Coelom
Body cavity
Coelomates
Animals having "true" coeloms, formed from tissue derived from mesoderm. The inner and outer layers of tissue that surround the cavity connect and form structures that suspend internal organs.
Pseudocoelomates
Some triploblastic animals have a body cavity that is formed from mesoderm and endoderm.
Acoelomates
Triploblastic animals lacking a body cavity altogether.
Protostone Development
Molluscs, Annelids
Spiral and determinate
Mouth develops first
Deuterostome development
echinoderms, Chordates
Radial and indeterminate
Anus develops first
Spiral cleavage
Planes of division are diagonal to the vertical axis of the embryo; smaller cells are centered over the grooves between larger, underlying cells.
Determinate Cleavage
Rigidly casts ("determines") the developmental fate of each embryonic cell very clearly.
Radial Cleavage
Cleavage planes are lateral to the vertical axis of the embryo; the tiers of the cells are aligned one direction above the other.
Indeterminate Cleavage
Each cell produced by the early cleavage divisions retain the capacity to develop into a complete embryo.
Archenteron
An Embryo;s developing digestive tube which becomes the gut.
Blastopore
The indentation that during gastrulation leads to the formation of the archenteron.
Lophophore
A crown od ciliated tentacles that funtion in feeding.
Trocotphore Larva
Distinctive stage fo development for molluscs and annelids.
Invertebrates
Animals lacking a backbone.
Suspension Feeders
Animals that capture food particles suspended in the water that passes through their body, which in some species resembles s sac perforated with pores.
Spongocoel
Pores in the central cavity of a suspension feeder.
Osculum
Larger opening through which water flows out of the sponge.
Choanocytes
Collar cells lining the interior of the spongocoel, they are flagellated and engulf bacteria and other food particles by phagocytosis.
Mesohyl
Gelatinous region that separates two layers of sponge.
Amoebocytes
Cells that move through the moshyl and have many functions.
Hermaphrodites
Each individual functions as both male and female in sexual reproduction.
Gastrovascular cavity
The sac of a cnidarian that is the digestive compartment.
Polyps
Cylindrical forms that adhere to the substrate by the aboral end of their body (the end opposite the mouth) and extend their tentacles, waiting for prey.
Medusa
Resembles a flattened, mouth-down version of the polyp that moves freely in the water by a combination of passive drifting and contractions of its bell-shaped body.
Cnidocytes
Cell unique cnidarians that function in defense and prey capture.
Nematocysts
Specialized cnidae that contain a stinging thread that can penetrate the body wall of the cnidarain's prey.
Protonephridia
Networks of tubules with ciliated structures called flame bulbs that pull fluid through branched ducts opening to the outside.
Planarians
rhabditophoran; Genus Dugesia; Free-living, fresh-water species
Alimentary Canal
A digestive tube with two openings, a mouth and an anus present on rotifers.
Parthenogenesis
A type of asexual reproduction in which females produce only female eggs.
Ectopracts
Greek meaning outside anus. Colonial animals that superficially resemble clumps of moss.
Exoskeleton
External skeleton
Brachiopods
Lamp Shell, superficially resemble clams and other hinged-shelled molluscs, but the two halves of the brachiopod shell are dorsal and ventral, rather than lateral, as in clams.
Foot
A muscular foot used for movement in Coelomates like molluscs.
Mantle
A fold of tissue that drapes over the visceral mass and secretes a shell (if one is present).
Mantle cavity
Water-filled chamber found in many molluscs, which houses the gills, anus, and excretory pores.
Radula
A straplike organ used by molluscs to scrape food.
Torsion
In gastropods, a developmental process in which the visceral mass rotates up to 180°, causing the animal's anus and mantle cavity to be positioned above its head.
Ammonites
Shelled cephalopods
Cuticle
Tough external coat that is shed by some animals.
Molting
Process of shedding cuticle.
Arthropods
Segmented body, hard exoskleleton, and jointed appendages.
Open Circulatory system
Fluid called hemolymph is propelled by a heart through short arteries snd then into spaces called sinuses surrounding the tissues and organs.
Chelicerates
One of the four major lineages of arthropods consisting of sea spiders, horseshoe crabs, scorpions, ticks, mites, and spiders
Named for the claw-like feeding appendages claaed chelicerae, which serve as pincers or fangs. Anterior Cephalothorax and a posterior abdomen. lacking antennae, with simple eyes.
Myriopods
One of the four major lineages of arthropods; centipedes and millipedes
Hexapods
One of the four major lineages of arthropods including insects and their wingless, six-legged relatives
Crustaceans
One of the four major lineages of arthropods including crabs, lobsters, shrimps, barnacles, and many others
Eurypterids
Water Scorpions; earliest chelicerates. extinct.
Arachnids
Bulf of modern chelicerates; Cephalothorax has six appendages, the chelicerae; a pair of appendages called pediapalps that function in sensing, feeding, or reproduction, and four pairs of walking legs. Spiders, ticks, mites.
Book Lungs
In most spiders, gas exchange is carried out by stacked platelike structures contained in an internal chamber.
Mandibles
Jaw-like part of myriapods.
Incomplete Metamorphosis
The young (nymphs) resemble adults but are maller, have different body proportion, and lack wings. nymph undergoes a series of molts, each time looking more like an adult, reaching sexually maturity with the final molt.
Isopods
One of the largest groups of crustaceans, which includes terrestrial, fresh-water, and marine species, including pill bugs or wood lice.
Decapods
Crustaceans that includes lobsters, crayfishes, crabs, and shrimps.
Copepods
Planktonic crustaceans, which are the most numerous of all animals.
Echnoderms
Slow-moving or sessile marine animals like sea stars.
Water Vascular system
A network of hydraulic canals branching into extensions called tube feet that function in locomotion and feeding.
Vertebrates
Animals containing a back bone.
Chordates
Phylum Chordata that contains the vertebrates; Bilateral animals, within bilateria, they belong to the clade of animals known as Deuterostomia
Notochord
Longitudinal, flexible rod located between the digestive tube and the nerve cord.
Pharyngeal Clefts
In chordate embryos, one fo the grooves that separate a series of pouches along the sides of of the pharynx and may develop into a pharyngeal slit.
Pharyngeal Slits
In chordates embryos, one of the slits that form from the pharyngeal clefts and communicate to the outside, later developing into gill slits in many vertebrates.
Lancelets
The most basal group of living chordates, which get their name from their bladelike shape.
Tunicates
Member of the clade Urochordata, sessile marine chordates that lack a backbone.
Cranates
Chordates with a head.
Neural Crest
Feature unique to cranates, collection of cells that appears near the dorsal margins of the closing neural tube in an embryo.
Conodonts
Were slender, soft-bodied vertebrate with prominent eyes controlled by numerous muscles.
Gnasthostomes
Jawed vertebrates
Lateral Line System
Characteristic of aquatic gnasthostomes in which organs form a row along each side of the body and are sensitive to vibrations in the surrounding water.
Placoderms
Plate-skinned; earliest gnasthostomes
Acanthodians
Group of jawed vertebrates that emerged at roughly the same time as placoderms.
Chondrichthyans
Cartilage fish; have a skeleton composed predominately of cartilage, though often impregnated with calcium.
Sharks, Rays and their relatives.
Oviparous
Lay eggs that hatch outside the mother's body.
Oviviviparous
Retain the fertilized eggs in the oviduct; born after hatching in the uterus.
Viviparous
Young develop within the uterus and obtain nourishment from the mother's blood through a yolk sac placenta, by absorbing a nutritious fluid produced by the uterus, or by eating other eggs.
Cloaca
A common chamber that ha a single opening to the outside.
Osteichthyan
Vertebrates; clade gnasthostomes; have an ossified (bony) endoskeleton with a matrix of calcium phosphate.
Operculum
Protective bony flap that covers the gills of most fish.
Swim Bladder
An air sac that helps fish control their buoyancy.
Amphibians
Salamanders, frogs, and caecilians; tetrapods
Amniotes
Group of tetrapods whose extant members are the reptiles (including birds) and mammals.
Amniotic Egg
Contains four specialized membranes; the amnion, the chorion, the yolk sac, and the allantois.
Reptile
Clade includes tuataras, lizards, snakes, turtles, crocodillians, and birds, along with a number of extinct froups, such as plesiosaurs and icthyosaurs.
Ectothermic
Animals that absorb external heat as their main source of body heat.
Endothermic
Capable of maintaining body temperature through metabolic activity.
Parareptiles
Mostly large, stocky, quadrupedal herbivores.
Diapsids
Ancient reptile clade; derived characters pair of holes on each side of the skull, behind the eye socket; muscles pass through these holes and attach to the jaw, controlling jaw movement.
Lepidosaurs
A lineage of the diapsids which include tuataras, lizards, and snakes
Archosaurs
A lineage of diaspids that produced the crocodilians, pterosaurs, and dinosaurs.
Pterosaurs
Originated in the alte Triassic, were the first to exhibit flapping flight.
Dinosaurs
Diversified into a vast range of shapes and sizes.
Theropods
Bipedal carnovores.
Ratites
Consists of ostrich, rhea, kiwi, cassowary, and emu- all flightless birds.
Synapsids
Member of an amniote clade distinguished by a single hole on each side of the skull. Synapsids include mammals.
Montremes
Found only in Australia and New Guinea and are represented by one species of platypus and four species of echnidnas (spiny anteaters). Lay eggs, have hair, produce milk, but they lack nipples. Milk is secreted byl glands on the belly of the mother. After hatching, the baby sucks the milk from the mother's fur.
Marsupials
Opossums, kangaroos, and Mole, Sugar glider, Wombat, Tasmanian devil
Placenta
The lining of the uterus and the extraembryonic structure in which nutrients diffuse into the embryo from the mother' blood.
Eutherians
Placental mammals; Placentas are more complex than those of marsupials.
Opposable Thumb
Can touch the ventral surface (fingerprint side) of the tip of all four fingers with the ventral surface of the thumb of the same hand.`
Anthropoids
Includes monkey and apes
Paleoanthropology
Study of human origins.
Hominins
20 extinct species that are more closely related to humans than to chimpanzees.