164 terms

Animal Biology Test 4- GSU


Terms in this set (...)

Chordata tree
Animals in which the blastopore becomes the anus during early embryonic development
- Evolution of an endoskeleton
An animals that at some point during its development has Dorsal hollow nerve chord, notochord, gill structures, post-anal tail,endostyle examples include lancelets tunicates and vertebrates

All contain the following during development
1. Notochord
2. Dorsal Nerve chord
3. Post anal tail
4. Pharyngeal slits/gills
5. Endostyle
A member of a group of slow moving or sessile marine animals characterized by a rough or spiny skin, a water vascular system, an endoskeleton, and a radial symmetry in adults, with examples such as sea stars, sea urchins and sand dollars
A rod of tough, flexible material that runs the length of a creature's body, providing the majority of its support
- eventually becomes the vertebral column in some species
Dorsal nerve chord
a hollow tube above the notochord
Pharyngeal gills
gill structure in the pharynx; found in chordate embryos & some adult chordates
- Used for filter feeding in some chordates
- Becomes the bones of the jaw and inner ear in more developed chordate species
Post anal tail
a tail that extends beyond the anus; exhibited by all chordates at some stage of development
- Humans after development have lost their post anal tail
Ciliated cells that produce a mucus sheet used to trap food particles
- located in the ventral pharyngeal wall during development
- Develops into the thyroid gland in many chordates
All of the non-vertebrate chordates are commonly referred to as what?
- simplest chordates out there
- generally live in marine environments
filter feeders
- Tunicates and Cephalochordates
Members of the subphylum Urochordata, sessile marine chordates that lack a backbone.
-Endostyle and pharyngeal slits exists in the adult form
-doesn't really have a head
One of the three major chordate lineages compromising small, mobile organisms that live in marine sands and suspension feed; also called lancelets or amphioxus
- contain all 5 devlopmental structures in the adult form
Vertebrata tree
Jawless fish; hagfish and lampreys
- ALSO lack paired fins
- First to have a developed tripartite brain
- Have no eyes or true jaws, attach to flesh; break down things so they're detritivorous
- No scales
- Cartilagenous
- Slime glands
- Rasping tongue with keratinized plates in the mouth
- Rely on senses of smell and touch
Class Petromyzontida
- parasitic, they attach to other fish and scrape away at the skin and eventually sucks up tissues and body fluids of the host.
- live in marine AND freshwater meaning they can OSMOREGULATE
- Naked skin
- cartilagenous
- dorsal fin
- Oral disk with keratinized plates and rasping tongue
- External gill slits
- Go to freshwater to reproduce
- Die after spawning
- MODEL ancestor to all vertebrates
have vertebrae and jaws that evolved from the structural support of pharyngeal slits
- a clade which is named for "jawed" mouth; posses more Hox genes, enhanced smell and vision, and lateral line system Ex) sharks, rays, lungfishes, amphibians, reptiles, mammals
Cartilaginous fish
-Sharks and rays
- have scales
ray finned fish
- a type of vertebrate having a rigid skeleton, with bony spines, and a mouth at the apex of the body
- Include tuna, trout, and goldfish, they have bony skeleton, swim bladder, and operculum, has a lateral line and has a vertebral column,
Lobe finned fish
- Paired pectoral and pelvic fins supported by bony struts. These fins evolved into arms and legs for walking on land
bony fish- have gill covers, swim bladders, and lateral lines
- Actinopterigii
- Sarcopterigii
sarcopterygians. it means they are a bony fish (osteichthyes) and that they are lobe finned (sarcopteryians)
- what ancient fish provided insight into the evolution of tetrapods
lung fish
-species have both gills and lungs; can survive in long droughts through aestivation by forming a cocoon of dried mucus and mud
-Because they have 'fleshy fins' or lobe fins, their limbs were covered in muscle and skin, whereas tetrapods have four feet.
- sarcopterygii
bony fish (Nemo and salmon) -> have a swim bladder, gill flap, and lateral line; sharks and rays do not
- actinopterigii and sarcopterigii
Mineralized dermal tissue
Evolution of scales from gnathostomata and onwards
overlapping bony structures on the outside of a fish
•Fish differ in the type, number and size of scales and some fish lack scales entirely (agnathans)
•Scales evolved independently in cartilaginous vs. bony fishes
•Offer a trade-off between protection and movement
Do sharks and rays have scales?
Placoid scales
small, tooth-like spines that make up a shark's skin
How did jaws evolve?
They are found in Superclass Gnathostomata, and evolved from the modifications of skeletal elements of gill arches
Most diverse chordate?
ray finned fishes
Cartilaginous fish vs Bony fish
lateral line
Sensitive receptor system that enables fish to detect gentle currents and vibrations in the water
paired fins
reduce the chance of rolling to the side and allow for better steering during swimming
- used for balance, steering, and propulsion
one of a series of muscle segments along the trunk of vertebrates, especially fish
-Provide Muscular movements for swimming and burrowing
•Each myomere pulls on several vertebrae
Caudal fins
fins that allow side to side movement and propels the fish forward
- more speed, less maneuverability
Why is it good for sharks to have cartilaginous bone?
•Cartilaginous skeleton is lighter than bone
- In addition to dynamic lift, this is how sharks keep themselves from sinking
Sharks are kept buoyant by a special oil in their liver called what
- Reason why their livers are huge
sharks and dynamic lift
lift from pectoral fins, if fish stops swimming it will sink
How is buoyancy controlled in bony fish?
•Most bony fish control buoyancy by adjusting the volume of gas in the swim bladder
•swim bladders are absent in tunas and many deepwater fish
Swim bladder
an air-filled sac near the spinal column in many fishes that helps maintain buoyancy
-An internal gas-filled organ that helps a bony fish stabilize its body at different water depths.
Fish circulation
closed circulatory system with 2 chambers (atrium and ventricle)
- One way circuit
Fish gills
Oxygen enters the bloodstream and carbon dioxide diffuses out at the gills. Take in water containing dissolved oxygen through their mouths and then pump it past the gills
•Water is moved into the mouth and passed over the gills
•Gill arches support rows of gill filaments that bear lamellae
•Gill rakers assist in food capture in filter feeding species
•In bony fishes (and chimaeras) the gills are covered by the operculum which protects gill filaments and streamlines body
Gills gas exchange
counter exchange system (blood and water flow in opposite directions)
Shark osmoregularity
Sometimes called osmoconformers. Salt diffuse in since they have lower salt concentration, but they also have urea and TMAO (protects proteins from urea), maintain osmolarity to that very close of seawater.
-The blood of cartilaginous fish is isoosmotic or slightly hyperosmotic to the surrounding seawater
Freshwater osmoregulation
If the solutes in the organism's body fluids are kept at a concentration higher than that of the external medium (e.g., lake water), this organism's body fluids are said to be hyperosmotic to the external medium and the organism is a hyperosmotic osmoregulator
-Animals gain water and some ions in food, uptake of salt ions and water by gills, excretion of salts and lots of water from kidneys, net movement of water into the animal (hyperosmotic)
Marine osmoregulation
Animals gain water and salt ions from food and seawater, salt is excreted via the gills and kidneys, osmotic water loss occurs through gills and body surface, net movement of water out of the fish (hypoosmotic)
modified pelvic fins on a male shark that allows for transfer of sperm to female
producing living young from eggs that hatch within the body
Bearing live young
sensory receptors that detect changes in electrical potential probably through voltage-gated ion channels. Allows some animals to electrolocate prey and obstacles and others to communicate by producing electrical potentials.
Ampullae of Lorenzi
nerve receptors found in a shark's snout which sense the electric fields generated by the muscles of fish and other potential prey
Reproduction of bony fish
•Most fishes are dioecious with external fertilization •Pelagic fish lay huge numbers of eggs
•Near-shore and bottom-dwelling species lay larger, typically yolky, non-buoyant and adhesive eggs.
•Many benthic spawners guard their eggs; usually the male is the guard.
What is different between ray fins and lobe fins?
One important difference between these groups is found in these paired fins. Those belonging to lobe-fin fishes articulate with the shoulder or pelvis via a single bone (humerus or femur) and contain extensive musculature. On the other hand, the paired fins of ray-fins are supported by lepidotrichia (thin, long rays of endoskeletal bone) and are powered primarily by muscles located inside the body trunk.
countercurrent exchange
the opposite flow of adjacent fluids that maximizes transfer rates; for example, blood in the gills flows in the opposite direction in which water passes over the gills, maximizing oxygen uptake and carbon dioxide loss.
neural crest
A band of cells along the border where the neural tube pinches off from the ectoderm; the cells migrate to various parts of the embryo and form the pigment cells in the skin, bones of the skull, the teeth, the adrenal glands, and parts of the peripheral nervous system.
Transitional animals
Amphibians, mid evolutionary animals in the water to land transitions
Was not quite a fish and not quite a tetrapod. It had stout, stubby front fins with flexible wrists that likely enabled it to prop itself up on land, but it had no digits. It had gills and lungs.
- descendants of lobe finned fishes
Evolutionary structures in the water to land transition
1. Jointed fins in lobe finned fish led to the origin of limbs in tetrapods
2. Development of the pelvis to arrange body weight
Skeletal system of amphibians
- Greater ossification than fish
- axial to appendicular musculature
Amphibian respiratory system
- Evolution of lungs from the swim bladder
- Positive pressure breathing still with the buccal cavity
- porous skin for greater gas exchange
Amphibian cardiovascular system
2 atria, 1 ventricle
- Mixing of oxygenated and deoxygenated blood
- two way closed system
Amphibian integumentary system
Skin is permeable to water and gases: important for respiration (NEEDS TO BE MOIST)
-Thicker skin than fishes
- kept moist via mucous glands
Amphibian feeding
Aquatic larvae are (mostly) herbivorous or detritus feeder
- Adult anurans are carnivorous
-expansive tongue
Frogs and toads
Order including the newts and salamanders
Without legs; caecilians
Evolutionary adaptations of frogs
Amphibian nervous system
Brain - well developed for basic functions (sight, olfaction, and movement) 10 cranial nerves Spinal cord extends to the tip of the tail in amphibians and caecilians; ends in lumbar region in frogs and toads Animal dependent upon spinal segmental reflexes to control movement
Also called thryoid hormone, thyroxine is produced and secreted by follicle cells in the thyroid gland. it targets all cells in the body and increases overall body metabolism and stimulates METAMORPHOSIS
The copulatory embrace of frogs and toads, during which the male fertilizes the eggs that are released by the female.
Frog reproductive cycle
Amplexus fertilizes female eggs
- tadpoles hatch in 6-9 days
- 3 pairs of internal gills develop
smooth skin, small eyes, blind, or nearly blind, have long worm like bodies, with no legs and are vertebrates
-internal fertilization
long tail, long body, with two pairs of legs, have smooth moist skin
-carnivorous young AND adults
- low metabolic rate/ectoderms
Metamorphosis is under hormonal control (thyroid gland):
-lungs form and gills are gradually reabsorbed
-digestive system becomes adapted for a carnivorous diet
-In anurans the tail is reabsorbed and the limbs form
-fins on tails of larval salamanders are usually lost
The retention in an adult organism of the juvenile features of its evolutionary ancestors.
-perennibrachiate= is the condition of an organism retaining branchae, or gills, through life; This condition is generally said of certain amphibia, such as the mudpuppy
Refers to the membrane surrounding the fetus. This was a way to overcome water dependence with the amniotic egg since it keeps the egg from drying. Kidneys and large intestines modified for water retention.
Adaptations of amniotes
Amniotic egg
A shelled, water-retaining egg that enables reptiles, birds, and egg-laying mammals to complete their life cycles on dry land
•Eliminated the need for aquatic environment during reproduction
•Allows for larger and faster growing embryos
Membrane that encloses the embryo in protective amniotic fluid
the extraembyonic membrane of birds, reptiles and mammals that serves as a site for the storage of noxious excretion products
Yolk sac
Membrane that encloses the nutrients for the growing embryo
membrane that lies under the shell of an egg and allows for diffusion of respiratory gases between the outside environment and the inside of the shell.
- becomes the placenta in mammals
Keratined skin of amniotes
•Keratin forms hair, feathers, scales, claws, nails, hooves, etc.
•Lipids reduce water loss from the skin
- Prevents desiccation
Amniote lungs
•Lungs of amniotes have a greater surface area than those of anamniotes
•Air is drawn into the lungs (aspiration) as the thoracic cavity (and lungs) expand
•Negative Pressure
Amniote Cardiovascular system
Better separation of pulmonary and systemic circuits
•Complete separation in Archosauria and Mammalia
•Higher blood pressure supports higher metabolic rates and activity levels because more oxygen faster to the tissues
- 4 chambered, closed
Nitrogen excretion in amniotes
- secreted as urea
Amniotic brain
larger cerebrum and cerebellum
-Higher level cognition and finer movement
-better sensory reception
egg-laying mammal with webbed feet
-venomous and electroreceptors
the ability to detect magnetic fields and orient using them
-birds, naked mole rats
the process of using reflected sound waves to find objects; used by animals such as bats
have single opning in the outer layer of the skull just behind eye socket
- gave rise to mammals
reptiles and birds, turtles (lepidosaurs and archosaurs, anapsids)
a reptile of a group characterized by the lack of temporal openings in the skull, including the turtles and their relatives.
Reptiles possessing a skull with two pairs of openings behind each eye socket; includes squamates, birds, crocodiles, and dinosaurs
- lepidosaurs and archosaurs
snakes and lizards
-kinetic skull
The reptilian group that includes crocodiles, alligators, dinosaurs, and birds.
Turtles and tortoises
- Shell=carapace
- Underbelly= plastron
-spinal column fused to the carapace
- creates negative pressure by moving shoulder muscles
- temperature determined sex determination
Suborder Sauria, Order squamates

Chameleons, bearded dragons and iguanas are all varieties of
-Suborder Sauria, Order squamates
164 species in South America, Africa, and Mediterranean; limb reduction or complete loss and rudimentary eyes
Snakes order of squamates
Kinetic skull
Modified skull without a dermal bone ventral and posterior to the lower temporal opening in lizards and snakes; enables squamates to seize and manipulate their prey and increases the effective closing force of the jaw musculature
•This allows them to seize and manipulate prey, and effectively close the jaw with force.
non venomous snakes
kill prey by constriction or by biting and swallowing it while still alive
Venomous snakes
Kill prey by injecting it with venom before swallowing
-Most snake venoms are a complex combination of venom types.
•Neurotoxins act on the nervous system, causing blindness or stopping respiration.
•Hemorrhagin-type venoms break down blood vessels; blood leaks into tissue spaces.
-elastic ligament in jaws to eat prey whole
Jacobsons organ
sensory receptor found in the top of the mouth that collects particles out of the air allowing lizards & snakes to locate prey and avoid *predator
pit organ
Heat sensitive structures used to identify prey; bird or mammals
Order Sphenodonta: Tuataras
•Only two living species -Restricted to small islands in New Zealand) represent this ancient lineage
•Only survivors of a group of reptiles that roamed the earth at the same time as the dinosaurs
•Skull is nearly identical to diapsid skulls of 200 million years ago
•Sphenodon represents one of the slowest rates of evolution known among vertebrate
•Modern crocodilians are classified in three families:
-Alligators and caimans •found primarily in the New World; they have a broader snout
. -Crocodiles •widely distributed and include the huge saltwater crocodile.
-Gavial •One species occurs in India and Burma; it has a very narrow snout.
•Thecodont dentition where teeth are set in sockets
•Four-chambered heart
•Temperature dependent sex determination
- Low temp= female
- High temp= male
Three types of turtles
tortoise, box turtles, snapping turtle
the first "bird". still had reptile-like jaw, claws and a tail
What are the two necessary adaptations for flight?
- Increase power
-Decrease weight
What are the two living types of birds?
"old jaws": skeletal anatomy of palate is more primitive and reptilian than that in other bird
-generally flightless
many more descendants, most of which have retained the ability to fly
projections or barbs that link that with those above and below them to keep all the barbs connected, making a solid feather surface
grooming behavior that involves combing the feathers with the beak as a way of getting the barbules of the feathers to "re-hook" ad to distribute oils, etc.
What are the modified scales made of keratin called that cover a bird?
Bird adaptations of the skeletal system
-pneumatized bone
-keel sternum
- fusion skeletal elements and reduction in the number of bone
- loss of vertebrate
perching tendons
When the bird touches the branch there is an automatic grasp of the toes in a pincerlike fashion. This is due to the special arrangement of the leg tendons. These tendons, which are nexes between muscles and bones, are long and run from the heel to the phalanges (toe bones)
- No energy wasted
Bird temperature regulation
Bird Circulatory system
- 4 chambered heart
-faster heartbeat to upkeep energy expenditure at the tissues
-Much higher basal heart rate than mammals
-Inversely proportional to size
bird lungs
Unidirectional to maintain a high Po2 gradient.
=work in a way that the air only has one direction of flow
•Made possible by a series of air sacs and a lung filled with tubular parabronchi
•Birds do NOT possess alveoli
birds that consumes great varieties of food.
birds that eat a specialized diet
Eating like a bird
- Birds have to eat A LOT to maintain their metabolic expenditure
- 30-100 percent of their own body weight
Bird crop
Stores food in esophagus and moistens it
Found in digestive tract of birds, earthworms, and grasshoppers. Thick muscular wall; breaks down food mechanically via keratinized plates
Dynamics of bird flight
Specialized flight
Specialized wings
Bird vision
Most birds can detect ultraviolet (UV) light
- tetrachromatic
Bird muscular adaptations
-Decreasing weight,increasing power
-Muscles provide aerodynamic stability
-Main leg muscle mass is in the thigh
-All of the muscles moved to the ventral side of the bird
Aspect ratio of wings
High=fastest low= increase maneuverability
Bird brain
Avian brain much more developed than reptile
- expansion of the forebrain
- cerebellum: movement, coordinated flight
Arctic terns
What is the longest regular migration by any known animal?
Two forms of migration navigation
Essential characteristics of mammals
-Skin & Hair
Mammalian integument
mammary gland
Specialized organs in mammals that produce milk to nourish the young
apocrine gland
Sweat glands in the pubic and underarm areas that secrete thicker sweat, that produce odor when come in contact with bacteria on the skin
eccrine gland
Found all over the body, primarily on the forehead, palms and soles; have a duct and pore; no odorous sweat
- What are the glands of skin that produce a thin, watery secretion
sebaceous gland
Any of the small sacculated glands lodged in the substance of the derma, usually opening into the hair follicles, and secreting an oily or greasy material composed in great part of fat which softens and lubricates the hair and skin.
exocrine gland
gland that releases its secretions through tubelike structures called ducts outside the body
-not in humans
guard hairs
Long, coarse hairs that forms a protective coating over an animal's under fur
- thicker and keratinized
soft, insulating hair
True horns
True Horns-Family Bovidae (sheep, goats, buffalo, cattle, etc.)
-Hollow sheath of keratinized epidermis covering a core of bone from the skull
- Never Shed
-found in both males and females
bony, branching growths on the head of a male deer, elk, or moose
-shed each season
Giraffe horns
boney core surrounded by bony skin
Skeletal adaptations of mammals
skull balances on top of the spinal column, foramen magnum is centered, S-curved spine supports weight of upper body, pelvic structure and articulation of the femur and hip sockets modified to deal with stress of walking upright
- legs shift under the body
Animals having teeth of different shapes
having teeth that are uniform in form, shape, and function.
- reptiles
dental formula
The numerical description of a species' teeth, listing the number, in one quadrant of the jaws, of incisors, canines, premolars, and molars.
types of teeth
incisors, canines, premolars, molars
Decidious set
20 baby teeth, milk teeth
two different sets of teeth (milk teeth and permanent teeth)
one heat per breeding season
multiple estrus per breeding season
Name the subclass that the Platypus (monotremes) and the Long-beaked Echidna belong to?
A monotreme in clade prototheria. Hedgehog like that eat ants and termites. 2 Clades, short beaked from Australia and long beaked from New Guinea.
-Eggs are incubated in an abdominal pouch
Subclass Theria, Infraclass Metatheria
Subclass Theria Infraclass Eutheria
viviparous placental mammal
•They have an investment in a prolonged gestation in contrast to marsupials with an investment in prolonged lactation.
•The embryo in the uterus is nourished through a chorioallantoic placenta.
•Gestation is longer than in marsupials and is much longer for large mammals.
-Mice: 21 Days -Elephants: 22 months
•Gestation and body size are loosely correlated because there is variation in maturity at birth
. -Antelope young: furred, eyes open and able to run
-Mice: blind, naked, helpless
Mammal feeding
Whales, dolphins, and porpoises
- closest relative is the hippo
-nurse their young underwater
- nostrils become the blowhole
- hindlimbs reduced in size to be flipper like

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