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210 terms

Unit 4 Exam

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Herbivore
animal that eats only plant or algae
Carnivore
animal that eats meat
Omnivore
animal that eats plants and meat
Ingestion
act of eating, first main stage of food processing
Digestion
mechanical and chemical breakdown of food into small molecules for body to absorb, second stage of food processing
Gastrovascular Activity
digestive compartment with single opening as the mouth
Mouth
opening through which food is taken
Pharynx
organ in a digestive tract that receives food from oral cavity
Esophagus
channel that conducts food by peristalsis, from pharynx to stomach
Stomach
pouch like organ in digestive tract that grinds food
Gizzard
pouch like organ in digestive tract where food is mechanically ground
Intestine
region of digestive tract located between gizzard and anus where chemical digestion and nutrient absorption occur
Anus
opening through which human waste is expelled
Alimentary Canal
digestive tract consisting of tube running between mouth and anus
Crop
pouch-like organ in digestive tract where food is softened and can temporarily be stored
Sphincter
ringlike valve, consisting of modified muscles that regulates passage between some compartments of alimentary canal
Saliva
salivary gland secretion that contains substances to lubricate food
Oral Cavity
mouth of an animal
Salivary Glands
glands associated with oral cavity that secret substances to lubricate food and begin process of chemical digestion
Gastric Juice
collection of fluids secreted by stomach
Gastrin
digestive hormone that stimulates secretion of gastric juice
Chyme
mixture of partially digested food and digestive juices formed in stomach
Small Intestine
longest section of alimentary canal
Pancreas
gland with dual functions: digestive portion secretes enzymes into small intestine, endocrine portion secretes insulin and glucagon into blood
Bile
mixture of substances produced by liver and stored in gallbladder, emulsifies fats
Gallbladder
organ that stores bile and releases it into the small intestine
Duodenum
first portion of the vertebrate small intestine after stomach, where chyme mixes with bile and digestive enzymes
Villi
fingerlike projection of inner surface of small intestine
Large Intestine
colon, tubular portion or vertebrate alimentary tract between small intestine and anus, water absorption and formation of waste
Cecum
blind outpocket at beginning of of large intestine
Appendix
small fingerlike extension of vertebrate cecum
Rectum
terminal portion of large intestine where waste is stored until eliminated
Metabolic Rate
total amount of energy an animal uses in a unit of time
Basal Metabolic Rate (BMR)
number of kilocalories a resting animal requires to fuel its essential body processes
Undernourishment
condition that results from a diet that consistently supplies less chemical energy than the body requires
Malnourishment
long term absence from a diet or essential nutrients
Overnourishment
consumption of more food energy than the body needs
Circulatory System
organ system that transports materials such as nutrients, O2 and hormones to body cells
Heart
muscular pump that propels blood through vessels to body
Blood
connective tissue with fluid matrix called plasma in which blood cells are suspended
Open Circulatory System
circulatory system in which blood is pumped through open ended vessels and bathes tissues and organs directly
Closed Circulatory System
circulatory system in which blood is confined to vessels and is separate from intestine fluid
Cardiovascular System
closed circulatory system with a heart and branching network of arteries, capillaries and veins
Arteries
vessel that carries blood away from heart to rest of body
Vein
vessel that returns blood to the heart
Capillaries
blood vessel that conveys blood between an arteriole and a venule, enables exchange of nutrients
Atrium
heart chamber that receives blood from the veins
Ventricle
heart chamber that pumps blood out of the heart
Arterioles
vessel that conveys blood between an artery and capillary bed
Capillary Beds
network of capillaries that infiltrate every organ and tissue in body
Venules
vessel that conveys blood between capillary bed and vein
Pulmonary Circuit
one of two main blood circuits in vertebrates, conveys blood between heart and lungs
Systemic Circuit
one of two main blood circuits in vertebrates, conveys blood between heart and rest of body
Pulmonary Arteries
large blood vessel that conveys blood from heart to lung
Pulmonary Veins
blood vessel that conveys blood from a lung to the heart
Aorta
artery that conveys blood directly from left ventricle to other arteries
Cardiac Cycle
alternating contractions and relaxations of the heart
Heart Rate
frequency of heart contraction
Heart Murmur
hissing sound that most often results from blood squirting backwards through leaky valve in heart
SA Node
pacemaker of the heart, located in right wall of atrium, sets rate and timing at which cardiac muscles contract
AV Node
region of specialized heart muscle tissue between left and right atria where electrical impulses are delayed for about 0.1 second before spreading to both ventricles and causing them to cotnract
Heart Attack
damage or death of cardiac muscle cells and the resulting failure of the heart to deliver enough blood to the body
Cardiovascular Disease
diseases of the heart and blood vessels
Stroke
death of nervous tissue in the brain, usually resulting from rupture or blockage of arteries in the head
Blood Pressure
force that exerts blood against the walls of blood vessels
Pulse
rhythmic stretching of arteries caused by pressure of blood during contraction of ventricles
Hypertension
abnormally high blood pressure, above 140/90
Red Blood Cells
erthrocyte, blood cell containing hemoglobin which transports O2
White Blood Cells
leukocyte, blood cell that functions in defending body against infections or cancer
Plasma
liquid matrix of blood in which blood cells are suspended
Platelets
pinched-off cytoplasmic fragment of a bone marrow cell, circulates blood
Phagocytes
white blood cell that engulfs bacteria, foreign proteins and remains of dead body cells
Anemia
condition in which an abnormally low amount of hemoglobin or low number of red blood cells results in body cells receiving not enough oxygen
Erythropoietin (EPO)
hormone that stimulates production of red blood cells
Stem Cells
unspecialized cell that can divide to produce an identical daughter cell and a more specialized daughter cell, which undergoes differentiation
Leukemia
type of cancer of the blood-forming tissues, characterized by an excessive production of white blood cells
Nervous System
organ system that forms a communication and coordination network between all parts of an animal's body
Neuron
nerve cell functional unit of nervous system, carrying signals
Central Nervous System
integration and command center of the nervous system, the brain and spinal cord
Peripheral Nervous System
network of nerves and ganglia carrying signals into and out of central nervous system
Nerve
cable-like bundle of neuron fibers tightly wrapped in connective tissue
Ganglia
cluster of nerve cell bodies in a central nervous system
Sensory Input
conduction of signals from sensory receptors to processing centers in central nervous system
Integration
interpretation of sensory signals within neutral processing centers of the central nervous system
Motor Output
conduction of signals from a processing center in a central nervous system to effector cells
Effector Cells
cell capable of carrying out some action in response to a command from the nervous system
Reflexes
automatic reaction to a stimulus, mediated by spinal cord or lower brain
Sensory Neurons
nerve cell that receives info from sensory receptors and conveys the in the central nervous system
Interneurons
nerve cell, entirely within central nervous system, that integrates sensory signals and may relay command signals to motor neurons
Motor Neurons
nerve cell that conveys command signals from the central nervous system to effector cells
Cell Body
part of a cell, such as a neuron, that houses the nucleus
Dendrites
neuron fiber that conveys signals from its tip inward, toward the rest of the neuron
Axon
neuron fiber that conducts signals to another neuron or to an effector cell
Glia
supporting cell that is essential for the structural integrity and normal functioning of the nervous system
Myelin Sheath
series of cells, each wound around and thus insulating, the axon and nerve cell in vertebrates
Synapse
junction between two neurons, or between a neuron and effector cell, electrical or chemical signals are relayed from one cell to the other
Membrane Potential
charge difference between a cell's cytoplasm to the differential distribution of ions
Resting Potential
voltage across the plasma membrane of a resting neuron
Stimulus
factor that triggers sensory transduction in central nervous system
Action Potential
self-propogating change in voltage across plasma membrane of neuron
Synaptic Cleft
in chemical synapse, narrow gap separating synaptic terminal of transmitting neuron from receiving neuron or effector cell
Neurotransmitter
chemical transmitter that carries info from a transmitting neuron to a receiving cell
Centralization
presence of central nervous system distinct from peripheral nervous system
Cephalization
concentration of nervous system at anterior (head) end
Spinal Cord
dorsal hollow nerve cord in vertebrates, with brain makes up central nervous system
Brain
part of central nervous system involved in regulating and controlling bodily activity and interpreting info from senses transmitted through nervous system
Blood-Brain Barrier
system of capillaries that restricts passage of most substances into the brain, thereby preventing large fluctuations in brain's environment
Ventricles
heart chamber that pumps blood out of heart
Central Canal
narrow cavity in center of spinal cord that is continuous with fluid-filled ventricles from brain
Cerebrospinal Fluid
blood-derived fluid that surrounds, protects against infection, nourishes and cushions the brain and spinal cord
Meninges
layers of connective tissue that enwrap and protect brain and spinal cord
White Matter
tracts of axons within central nervous system
Gray Matter
regions of dendrites and clusters of nerve cell bodies within central nervous system
Cranial Nerves
nerve that leaves the brain and innervates an organ of the head or upper body
Spinal Nerves
in vertebrate peripheral nervous system, nerve that carries signals to or from spinal cord
Somatic Nervous System
component of vertebrate peripheral nervous system that carries signals to and from skeletal muscles
Autonomic Nervous System
component of vertebrate peripheral nervous system that regulates internal environment, made of sympathetic and parasympathetic divisions
Parasympathetic Division
set of neurons in autonomic nervous system that generally promotes body activities that gain and conserve energy, such as digestion
Sympathetic Division
set of neurons in autonomic nervous system that generally prepares body for energy-consuming activities
Enteric Division
part of autonomic nervous system consisting of complex networks of neurons in the digestive tract, pancreas and gallbladder
Forebrain
develops into thalamus, hypothalamus and cerebrum
Midbrain
develops into sensory integrating and relay centers that send sensory info to the cerebrum
Hindbrain
develops into medulla oblongata, pons and cerebellum
Cerebrum
largest, most sophisticated and most dominant part of vertebrate forebrain, made up of left and right cerebral hemispheres
Medulla Oblongata
part of vertebrate hindbrain continuous with spinal cord, passes data between spinal cord and forebrain and controls autonomic functions
Pons
part of vertebrate hindbrain that functions with medulla oblongata in passing data between spinal cord and forebrain and in controlling autonomic functions
Brainstem
functional unit of vertebrate brain, composed of midbrain, medulla oblongata and pons, serves as sensory filter, selecting which info reaches higher brain centers
Cerebellum
part of vertebrate hindbrain, planning center that interacts closely with cerebrum and in coordinating body movement
Thalamus
integrating and relay center of the vertebrate forebrain, sorts and relays selected info to specific areas in cerebral cortex
Cerebral Hemispheres
right or left half of the vertebrate cerebrum
Corpus Callosum
thick band of nerve fibers that connect the right and left cerebral hemispheres, enabling them to process info together
Cerebral Cortex
contains integrating centers for higher brain functions such as reasoning and speech
Lateralization
phenomenon in which two hemispheres of brain become specialized for different functions
Limbic System
functional unit of several integrating and relay centers located in human forebrain, interacts with cerebral cortex in creating emotion and storing memory
Memory
ability to store and retrieve info
Amygdala
integrative center of the cerebrum, part of limbic system that labels info to be remembered
Hippocampus
integrative center of cerebrum, part of limbic system that plays a central role in memory and learning
Short Term Memory
ability to hold info, anticipations or goals for a time and release them if they become irrelevant
Long Term Memory
ability to hold, associate and recall info over one's life
Parkinson's Disease
mental disorder caused by progressive brain disease and characterized by difficulty in initiating movements
Schizophrenia
mental disturbance characterized by psychotic episodes in which patients lose ability to distinguish reality from hallucinations
Bipolar Disorder
depressive mental illness characterized by mood swings
Community
assemblage of all organisms living together and potentially interacting in an area
Interspecific Interaction
relationships among individuals of different species in a community
Interspecific Competition
competition between individuals or populations of two or more species requiring a limited source
Mutualism
interspecific relationship in which both partners benefit
Coevolution
evolutionary change in which adaptations in one species act as a selective force on a second species, mutual influence on evolution of two different interacting species
Producers
organism that makes organic food molecules from CO2, H2O and other inorganic raw materials
Primary Consumers
organism that eats plants or algae
Secondary Consumers
organism that eats primary consumers
Tertiary Consumers
organism that eats secondary consumers
Quaternary Consumers
organisms that eats tertiary consumers
Detritivores
organism that consumes organic organic waste and dead organisms
Decomposers
prokaryotes and fungi that secrete enzymes that digest nutrients from organic material and convert them into inorganic forms
Detritus
dead organic matter
Decomposition
breakdown of organic materials into inorganic ones
Food Web
network of interconnecting food chains
Species Diversity
variety of species that make up a community
Keystone Species
species that is not usually abundant in a community yet exerts strong control on community structure by the nature of its ecological role or niche
Disturbances
in ecology, a force that changes a biological community and usually removes organisms from it
Ecological Succession
process of biological community change resulting from disturbance, transition in species composition of a biological community
Primary Succession
type of ecological succession in which a biological community arises in an area without soil
Secondary Succession
type of ecological succession that occurs where a disturbance has destroyed an existing biological community but left the soil intact
Invasive Species
non-native species that spread beyond original point of introduction and cause environmental or economic problems
Ecosystem
all the organisms in a given area, along with abiotic with which they interact
Energy Flow
passage of energy through components of an ecosystem
Chemical Cycling
use and reuse of chemical elements such as carbon within an ecosystem
Primary Production
amount of solar energy converted to chemical energy by autotrophs in an ecosystem
Biogeochemical Cycle
any of the various chemical circuits that involve both abiotic and biotic components of an ecosystem
Abiotic Reservoir
part of an ecosystem where a chemical, such as carbon, accumulates outside of living organisms
Nitrogen Fixation
conversion if atmospheric nitrogen into nitrogen compounds that plants can absorb and use
Biodiversity
variety of living things on earth
Biodiversity Crisis
current rapid decline in the variety of life on earth
Conservation Biology
goal-oriented science that endeavors to sustain biological diversity
Endangered Species
species that is in danger of extinction
Threatened Species
species that is likely to become endangered in the future
Ozone Layer
layer of ozone in upper atmosphere that protects life on earth from UV rays of sunlight
Phenotypic Plasticity
individual's ability to change phenotype in response to local environment conditions
Landscape Ecology
application of ecological principles to the study of structure and dynamics of of a collection of ecosystems
Movement Corridor
series of small clumps that connects isolated habitats
Biodiversity Hot Spots
small geographic area with an exceptional concentration of endangered and threatened species
Endemic Species
species whose distribution is limited to a specific geographic area
Zoned Reserve
extensive region of land that includes one or more areas that are undisturbed by humans
Restoration Ecology
use of ecological principles to develop ways to return degraded ecosystems to conditions similar as their original state
Adaptions
inherited characteristic that enhances an organism's ability to survive and reproduce in an environment
Evolution
descent with modification
Artificial Selection
selective breeding of domesticated plants and animals to promote occurrence of desirable traits
Natural Selection
process in which organisms with certain inherited characteristics are more likely to survive and reproduce
Extinction
irrevocable loss of a species
Fossil Record
chronicle of evolution over millions of years engraved in strata
Strata
rock layers where fossils are formed
Biogeography
study of past and present distribution of organisms
Homology
similarity of characteristics resulting from shared ancestry
Homologous Structures
structures in different species that are similar because of common ancestry
Vestigal Organs
structure of marginal importance to an organism
Evolutionary Tree
branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms
Population
group of individuals belonging to one species living in the same geographic area
Gene Pool
all the alleles for all the genes of a population
Microevolution
change in a population's gene pool over generations
Bottleneck Effect
genetic drift resulting from drastic reduction in population size
Founder Effect
genetic drift that occurs when a few individuals become isolated from a larger population, with the result that the composition of the new population's gene pool is not reflective of the original population
Fitness
contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals of about equal size
Stabilizing Selection
natural selection that favors intermediate variants by acting against extreme phenotypes
Disruptive Selection
natural selection in which individuals on both extremes of a phenotypic range are favored over intermediate phenotypes
Sexual Dimorphism
marked differences between secondary sex characteristics of males and females 8
Sexual Selection
form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates
Balancing Selection
natural selection that maintains stable frequencies or two or more phenotypic forms in a population
Heterozygote Advantage
greater reproductive success for heterozygous individuals compared to homozygotes, preserves variation
Frequency-Dependent Selection
a decline in the reproductive success of individuals that have a phenotype that has become too common in a population
Neutral Variation
genetic variation that does not appear to provide a selective advantage or disadvantage