Unit 3 Flashcards
Radial symmetry
Body is shaped like a pie or barrel and can be divided into mirror imaged halves by any plane through its central axis
Bilateral symmetry
Central longitudinal plane divides the body into two equal but opposite halves
Cephalization
Evolutionary trend towards the concentration of sensory equipment at the anterior end of the body
Blastula
Hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals
Ectoderm
The outermost of the three primary germ layers in animal embryos. Gives rise to skin, nerves
Endoderm
Innermost of the three primary germ layers. Gives rise to gut lining
Mesoderm
Middle primary germ layer in a triploblastic animal embryo. Gives rise to muscle, skeleton, circulatory system. Develops into notochord
Gastrula
Embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, endoderm
Determinate cleavage
Embryonic development in protostomes that casts the fate of each embryonic cell very early
Cell types fixed early
Indeterminate cleavage
Early embryo cells can each form a complete organism
Epidermis
Outermost layer of cells in an animal
Suspension feeder
Aquatic animal such as sponge that feeds by sifting small organisms or food particles from water
Polyp
Sessile variant of the cnidarian body plan
Medusa
Floating, flattened, mouth-down version of cnidarian body plan
Gastrodermis
Stomach skin layer, lines gastrovascular cavity
Diploblastic
2 tissue layer (ectoderm &; endoderm, no mesoderm)
Cnidocytes
Stinging cells
Protonephridia
An excretory system, such as flame bulb system of flatworms, consisting of a network of tubules lacking internal openings
Simple organ for proper dilution
Septae
Segmented dividers
Ingestion
First stage of food processing in animals
Nephron
Tubular excretory unit of vertebrate kidney
Mantle
Surrounds visceral mass, secretes shell
One of three parts of mollusc
Visceral mass
Contains organs
Part of mollusc
Foot
For movement
Part of mollusc
Cuticle
External coat of nematodes and Arthropods
Molting
A process in which the exoskeleton is shed at intervals, allowing growth by the production of a larger exoskeleton
Entomopathogenic
(Insect disease causing) nematodes attack plant eating insects, helping crops
Temperate
Moderate, not extremely cold or extremely hot
Tracheal system of Arthropods
Branching air tubes via openings on lateral abdomen, thorax
Chelicera
One of a pair of claw like feeding appendages, inject venom
Isopod
Member of crustaceans, pill bugs or wood lice
Metamorphosis
A developmental transformation that turns an animal larva into either an adult or an adult like stage that is not yet sexually mature
Incomplete metamorphosis
A type of development in certain insects in which the young resemble adults but are smaller and have different body proportions
Water vascular system
Use sea water instead of blood for gas exchange; oxygen in, CO2 out
Echinoderm
A slow moving or sessile marine deuterostome with a water vascular system and in larvae bilateral symmetry. Include sea stars, brittle stars, sea urchins, sea cucumbers
Invertebrate
Animal with out backbone. Make up 95% of animal species
Notochord
Semirigid rod along length of body in embryo of chordate. Runs along dorsal part of body
Neural tube
Dorsal hollow nerve cord
Pharyngeal slit
In chordate embryo, one of the slits that form from the pharyngeal clefts and communicate to the outside. Later develop into gill slits in many vertebrae
Lancelet
Member of the clade cephalochordata, basal, invertebrate chordate
Hagfish
Chordate that lacks a backbone
Lamprey
Vertebrate that lacks jaws
Gnathostomes
Vertebrates with jaws
Tetrapods
Vertebrates with 4 limbs
Amphibians
Vertebrates with limbs but not amniotic eggs
Amniotes
Member of a clade of tetrapods named for key derived character, the amniotic egg, which contain specialized membranes, including fluid filled amnion that protect the embryo. Includes reptiles, mammals and birds
Extraembryonic
Outside of embryo
Amnion
Contains embryo and fluid to protect against shocks
Yolk sac
Contains nutrients that are transported to the embryo
Allantois
Waste receptacle
Chorion
Gas exchange
Lateral line system
Pits with sensory hairs detect changes in water pressure
Oviparous
Type of development in which young hatch from eggs laid outside the mothers body
Ovoviviparous
Eggs remain in oviduct, fed by yolk, then hatch and released
Viviparous
Young develop in females uterus, receive nourishment from mothers uterine blood or placenta
Swim bladder
An air sac that enables the animal to control its buoyancy in water
External fertilization
The fusion of gametes that parents have discharged into the environment
Internal fertilization
The fusion of eggs and sperm within the female reproductive tract. Sperm is usually deposited in or near tract
Ectothermic
Referring to organisms for which external sources provide most of heat for temperature regulation
Extant
Exist
Transitional fossil
Fossilized remains that exhibit traits common to both an ancestral and derived descendent groups
Gizzard
Muscular grinder in gut
Endothermic (homeothermic)
Heat generated by own metabolism
Mammary gland
Secretes milk, characteristic of mammals
Diaphragm
Sheets of muscle between thorax and abdomen
Secondary palate
Separates food and air paths, prey in mouth and still breath, chew longer; suckle and breathe
Exaptation
Trait that has been co-opted for use other than the one for which it was built
Marsupial
A mammal whose young complete their embryonic development inside a maternal pouch called the marsupium
Placenta
Structure in pregnant uterus for nourishing a viviparous fetus with the mothers blood supply
Monotremes
Egg laying mammals that lack nipples
Eutherians
Placental mammals whose young complete embryonic development in uterus, joined to mother by placenta
Opposable thumb
Thumb can touch tips of all other fingers, allowing great dexterity and ability to grip
Hominindae
A member of the human branch of the evolutionary tree
Founder effect
A type of random genetic drift
Lactase persistence
Continuing to produce lactase, an enzyme that digest lactose
Stimulus
In feedback regulation, a fluctuation in a variable that triggers a response
Homeostasis
The steady-state physiological condition of the body
Predation
An interaction between species in which one species, the predator, eats the prey
Signal
In animal behavior, transmission of a stimulus from one animal to another
Innate behavior
All members of a population exhibit same behaviors even if they develop under different conditions
Learned behavior
Behavior of an individual is modified based on its specific experiences
Imprinting
Combination of innate and learned behaviors. Long lasting behavioral response formed to an individual or object
Associative learning
Association of a stimulus with a reward or punishment
Social learning
Observing and copying behaviors of other individuals
Foraging
Behaviors for locating and obtaining food
Optimal foraging
The basis for analyzing behavior as a compromise between feeding costs and feeding benefits
Monogamy
1 mate for males and females
Polygyny
More than one mate for males
Polyandry
More than one mate for females
Polygynandry
Multiple mates by both males and females
Polygamy
Type of relationship in which an individual of one sex mates with several of the other
Altruism
Behavior that reduces an animals fitness but increases the fitness of another member of the population
Reciprocal altruism
Individual benefits from helping a non relative if the relative later returns the favor
Heterotrophs
An organism that obtains food by eating another organism
Gastrovascular cavity
A central cavity with a single opening in the body of certain animals that functions in both digestion and distribution of nutrients
Pharynx
Region of digestive tube behind mouth
Dentition
Tooth pattern
Arboreal
Tree dwelling
Behavior
Action carried out by muscles under control of the nervous system in response to a stimulus
Tissues
Group of cells similar in appearance and or function
Fixed action pattern
A series of programmed behaviors in response to a stimulus even if the stimulus stops
