Nelson Biology Definitions Essay

Genus (plural genera): taxonomic group of a closely related species. Classification: the grouping of organisms based on a set of criteria that helps to organize and indicate evolutionary relationships. Hierarchal classification: the method of classifying organisms in which species are arranged in categories from most general to most specific. Rank: a level in a classification scheme, such as phylum or order. Taxonomy (plural tax): a named group of organisms such as phylum Chordate or order Rodents. Ancestor: an organisms (or organisms) from which other groups of organisms are descended.

Anatomy: the branch of biology the deals with structure and form, including internal systems. Physiology: the branch of biology dealing with physical and chemical functions of organisms, including internal processes. Phylogeny tree: a branching diagram used to show the evolutionary relationships among species. Structural diversity: a type of biological diversity that is exhibited in the variety of structural forms in living things, from internal cell structure to body morphology. Prokaryotic: a smaller, simple type of cell that does not have a membrane-bound nucleus.

Eukaryotic: a larger complex yep of cell that does have a membrane-bound nucleus. Dichotomous key: an identification tool consisting of a series of two-part choices that lead the user to a correct identification. Author: an organism that captures energy from sunlight (or sometimes non-living substances) to produce its own energy-yielding food. Heatproof: an organism that cannot make its own food and get its nutrients and energy from consuming other organisms. Species diversity: the variety of abundance of a species in a given area.

Genetic diversity: the variety of heritable characteristics (genes) in a population of interbreeding individuals. Ecosystem diversity: the variety of ecosystems in the biosphere. Gene pool: all the genes of all the individuals in a population. Population: a group of individuals of the same species in a specific area at a specific time. Resilience: the ability of an ecosystem to remain functional and stable in the presence of disturbances to its parts. Viruses: a structure that contains strands of DNA or RNA surrounded by a protective protein coat; it cannot live independently outside of cells.

Sapid: the outer protein layer that surrounds the genetic material of a virus. Replication: the monumental process of all cells, in which the genetic material is copied before the cell reproduces. Lit cycle: the replication process in viruses in which the virus’s genetic material uses the copying machinery tot the most cell to make new viruses. Lysergic cycle: the replication process in which the viral DNA enters the host cell’s chromosome; it may remain dormant and later activate and instruct the host cell to produce more viruses.

Prior: an infectious particle that causes damage to nerve cells in the brain, and that appears to consist mostly or entirely of a single protein. Bacterium (plural bacteria): an individual prokaryotic cell or a single species that is in the domain Bacteria. Archdeacon (plural arched): an individual prokaryotic cell or a single species that is in the domain Arched. Cuscus (plural Cisco): is a microorganism whose overall morphology is spherical or nearly so. Bacillus (plural bacilli): is a microorganism whose overall morphology is rod shaped.

Antihistamines: a biological (or chemical) process that produces methane as a by- product. Extremities: an organism that lives in habitats characterized by extreme conditions. Mesosphere: an organism that lives in habitats characterized by moderate conditions. Binary fission: the asexual form of reproduction used by most prokaryote (and some eukaryotic organelles), in which a cell divides into two genetically identical cells (or organelles). Conjugation: a process in which there is a transfer of genetic material involving two cells. Endoscope: a dormant bacterial cell able to survive for long periods during extreme conditions.

Gram stain: a stain that separates two major divisions (Gram positive and Gram negative) based on the cell wall’s response to the stain. Endometriosis: theory that explains how eukaryotic cells evolved from the symbiotic relationship between two or more prokaryotic cells. Indentations: a cell that is engulfed by another cell in endometriosis. Host cell: a cell that engulfs another cell in endometriosis. Protest: a eukaryotic organism, usually unicellular, that is not a fungus, plant, or animal. Parasite: an organism that benefits by living in or on another organism at the expense of that organism.

Pseudopodia (plural pseudopodia): a temporary cytoplasm extension that amoebas use for feeding and movement. Cilium (plural cilia): a short, hair-like rejection that functions in cell movement and particle manipulation when coordinated with other cilia. Flagellum (plural flagella): a long, hair-like projection extending from the cell membrane that propels the cell using a whip-like motion. Red tide: a coastal phenomenon in which tintinnabulations that contain red pigments are so concentrated that the seawater has a distinct red color. Alga (plural algae): a unicellular or multicultural photosynthetic, aquatic protest.

Plant: a multicultural photosynthetic eukaryote with cellulose-based cell wall. Embryo: an organism’s early pre-birth stage of development. Sporadic reproduction: sexual reproduction that alternates between gamete-making individual and a spore-making individual. Commemorate: the haploid plant in Sporadic reproduction that produces gametes by mitosis. Saprophyte: the diploid plant in Sporadic reproduction that produces spores by meiosis. Bryophyte: a small, non-vascular land plant; the formal name Bryophyte is reserved for the mosses, one group of bryophytes.

Gymnosperm: a vascular plant with non-enclosed seeds. Angiosperm: a vascular plant with seeds enclosed in protective tissue. Cone: a gymnosperm structure that contains male or female reproductive parts. Flower: a collection of structures in angiosperms used for sexual reproduction. Fruit: a mature ovary of a flower that protects and disperses dormant seeds. Monocot: a major cluster tot toweling plants that nave one cotyledon. Idiotic: a major cluster tot flowering plants that have two cotyledons. Fungus (plural fungi): a stationary heterocyclic eukaryotic organism whose cell walls contain chitin.

Happy (plural hyper): a multicultural, thread-like filament that makes up the basic structural unit of a fungus. McCollum (plural micelle): a complex, net-like mass made of branching hyper. Fruiting body: the sport-reproducing reproductive structure in fungi. Gossiper: a diploid structure that develops after two haploid hyper of opposite types combines and fuses their nuclei; this structure is characteristic of Gossiper fungi that reproduce sexually during unfavorable conditions. Caucus (plural ASCII): a small finger-like structure in which sac fungi develop spore.

Obsidian (plural obsidian): a club-shaped happy found in members of Biochemists; they bear spores called biospheres. Lichen: an organism that results from a naturalistic relationship between a fungus and a photosynthetic plant or alga. Invertebrate: an animal that does not have a backbone. Vertebrate: an animal with an internal skeleton and a backbone. Radial symmetry: a body plan that can be divided along any plane, through a central axis, into roughly equal halves. Bilateral symmetry: a body plan that can be divided along one plane, through the central axis, and into equal halves.

Ocelot: a fluid- filled body cavity that provides space for the development and suspension or organs and organ systems. Segmentation: the division of multicultural bodies into a series of repetitive parts. Polyp: the tube-shaped sessile body form of cnidarians. Medusa: the umbrella-shaped, free-swimming body form of cnidarians. Mantle: a membrane that surrounds a mollusk’s internal organs. Exoskeleton: an external skeleton that protects organs, provides support for muscle attachment, and protects against water loss and predation.

Notched: a flexible rod-shaped structure found in chordate animals, during vertebrate development it is replaced by the spine. Cartilage: the flexible, non-bony, tough material found in vertebrate nonetheless. Trapped: a vertebrate with two pairs of limbs; an amphibian, reptile, bird, or mammal. Ectoderm: the reliance on environmental heat for determining body temperature. Endothermic: the use of metabolic heat to maintain a high, constant body temperature. Mammary gland: a mammalian gland that produces and secretes milk for nourishing young.

Placenta: an organ in the pregnant uterus that exchanges nutrients and oxygen between the mother and developing offspring. Mass extinction: a large-scale dying out of a large percentage of all living organisms within an area over a short time. Biodiversity crisis: the current decline in genetic, species, and ecosystem diversity that may represent a mass extinction. Modeling: a scientific method in which an idea about a mechanism is formulated and real-life data are used to see if the data fit the model. Temperature sex determination: a system in which the sex of offspring is determined by the incubation temperature rather than by genes.

Unit 2: Genetic Processes Genetics: the study of heredity and variation of living organisms and how genetic information is passed from one generation to the next. Somatic cell: a plant or animal cell that torts the body tot the organism; excludes reproductive cells. Chromosome: a structure in the nucleus that contains DNA. Sister chromatic: one f two chromosomes that are genetically identical and held together at the centimeter. Centimeter: the region where two sister chromatics are held together in a chromosome. Spindle fiber: a microcircuit structure that facilitates the movement of chromosomes within a cell.

Connectors: a structure that helps to form the spindle fibers. Genome: the complete DNA sequence of an organism. Sex chromosome: an X or Y chromosome, which determines the genetic sex of an organism. Outcome: a chromosome that is not involved in determining the sex of an organism. Homologous chromosome: a chromosome that contains the same sequence of genes as another chromosome. Gene: a part of a chromosome that governs the expression of a trait and is passed on to the offspring; it has a specific DNA sequence. Allele: a different form of the same gene. Eukaryote: a photograph of pairs of homologous chromosomes in a cell.

Asexual reproduction: reproduction that requires only one parent and produces genetically identical offspring. Sexual reproduction: reproduction that requires two parents and produces genetically distinct offspring. Gamete: a male or female reproductive cell. Zygote: a cell formed by the fusion of two gametes. Fertilization: in humans, the Joining of male and female haploid gametes. Haploid: a cell that contains half the number of chromosomes of the parent cell. Diploid: a cell that contains pairs of homologous chromosomes. Meiosis: the cellular process that produces cells containing half the number of chromosomes as the parent cell.

Synapses: the aligning of homologous chromosomes during protease I and meiosis l. Cooperativeness: the process of producing male gametes (sperm) in mammals. Sogginess: the process if producing female gametes (eggs) in mammals. Crossing over: the exchange of chromosomal segments between a pair of homologous chromosomes. Non-disjunction: the failure of homologous chromosome pairs to separate during meiosis. Monsoons: the loss of a chromosome as a result of non-disjunction. Tourism: the gain of an extra chromosome as a result of non-disjunction. Selective breeding: the process of breeding plants and animals for desirable traits.

Artificial insemination: the process by which sperm are collected and concentrated before being introduced into the female’s reproductive system. Embryo transfer: the process by which an egg that has been fertilized artificially is transferred into a recipient female’s uterus. In vitro fertilization: the technique used to fertilize egg cells outside the female’s body. Cloning: a process that produces identical copies of genes, cells, or organisms. Gene cloning: the use of DNA manipulation techniques to produce multiple copies of a single gene or segment of DNA.

Recombinant DNA: a molecule of DNA that includes genetic material from different sources. Therapeutic cloning: the process of replacing an egg cell’s nucleus with the nucleus from a somatic donor cell to produce a cell line of genetically identical cells. Reproductive cloning: the process of producing genetically identical organisms. Stem cell: an undifferentiated cell that can develop and become specialized into different cell types of the body. Trait: a specific characteristic or feature exhibited by an organism. True breeding: organisms that exhibit the same traits, generation tater generation.

Cross: the fertilization of a female gamete of specific genetic origin with a male gamete of specific genetic origin. P generation: in breeding, the organisms initially crossed and are typically true breeding. Fl generation: the offspring of a cross of the P generation. Monophonic cross: a cross of two individuals that differ by one trait. IF generation: the offspring of a cross between the Fl generation. Dominant: the form of a trait that always appears when an individual has an allele for it. Recessive: the form of trait that only appears when an individual has two alleles for it.

Law of segregation: traits are determined by pairs of alleles that segregate during meiosis so that each gamete receives one allele. Genotype: the combination of alleles for any given trait, or the organism’s entire genetic make-up. Phenotype: the physical and physiological traits or an organism. Homozygous: an organism that has two identical alleles of a gene. Heterozygous: an organism that has two different alleles of a gene. Punned square: a grid used to illustrate all possible genotypes and phenotypes of offspring from genetic crosses. Test cross: a cross between a parent of unknown genotype and a homozygous recessive parent.

Debris cross: a cross of two individuals that differ in two traits due to two different genes. Law of independent assortment: during gamete formation, the two alleles for one gene segregate of assort independently of the alleles for other genes. Chromosome theory of inheritance: traits determined by genes are inherited through he movement of chromosomes during meiosis. Pedigree: a flowchart that uses symbols to show the inheritance patterns of traits in a family over many generations. Autocross inheritance: the inheritance of traits determined by genes on the autocross chromosomes.

Autocross dominant: the inheritance of a dominant phenotype whose gene is on an autocross chromosome. Autocross recessive: the inheritance of a recessive phenotype whose gene is on an autocross chromosome. Genetic counselor: a health-care professional with specialized training in medical genetics and counseling. Gene therapy: a technique aimed at treating genetic crosiers by introducing the correct form of the effective genes into a patient’s genome. Incomplete dominance: a condition in which neither alleles for a gene completely conceals that presence of the other; it results in intermediate expression of a trait.

Codename: the condition in which both alleles for a trait are equally expressed in a heterozygous; both alleles are dominant. Heterozygous advantage: a survival benefit for individuals who inherit two different alleles for the same trait. Continuous variation: a range of variation in one trait resulting from the activity of many genes. Polyclinic trait: a trait that is controlled by more than one gene. Linked genes: genes that are on the same chromosome and that tend to be inherited together. Sex-linked trait: a trait controlled by genes on the X or the Y chromosome.

Bioinformatics: a field of study that deals with using computer technology to create and analyze large databases of information. Genomics: the study of genomes and the complex interactions of genes that results in phenotypes. Genetic profile: the complete genotype of an individual, including various mutations. Unit 3: Evolution Extinct: describes a species that NAS completely disappeared trot Earth Adaptation: a structure, behavior, or physiological process that helps an organism survive and reproduce in a particular environment.

Mimicry: a structural adaptation in which a harmless species resembles a harmful species in calculation or structure. Variation: differences between individuals, which may be structural, functional, or physiological. Mutation: a permanent change in the genetic material of an organism; the only source of new genetic variation. Selective advantage: a genetic advantage that improves an organism’s chance of survival, usually in a changing environment. Natural selection: the process by which characteristics of a population change over many generations as organisms with heritable traits survive and reproduce, passing their traits to offspring.

Selective pressure: environmental conditions that select for certain characteristics of individuals and select against other characteristics. Fitness: the relative contribution an individual makes to the next generation by producing offspring that will survive long enough to reproduce. Artificial selection: selective pressure exerted by humans on populations in order to improve or modify particular desirable traits. Biotechnology: the use of technology and organisms to produce useful products. Monoculture: extensive plantings of the same varieties of a species over large expanses of land.

Paleontology: the study of ancient life through the examination of fossils. Catastrophic: the idea that catastrophes such as floods, diseases, and drought periodically destroyed species living in a particular region, allowing species from neighboring regions to repopulate the area. Unfamiliarity’s: Charles Allele’s theory (based on Hotpot’s theory) that geological processes operated at the same rates in the past as they do today. Inheritance of acquired characteristics: the idea that characteristics acquired during an organism’s lifetime can be passed on to its offspring.

Theory of evolution by natural selection: a theory explaining how life has changed and continues to change, during Earth’s history. Evolution: the process of genetic change in a population over time. Survival of the fittest: the idea that the organisms that are the fittest leaves the most offspring, so those organisms win the struggle for survival; phrase coined by John Spencer. Descent with modification: Darning’s theory that natural selection does not demonstrate progress, but merely exults from a specie’s ability to survive local conditions at a specific time.

Fossil record: the remains and traces of past life that are found in sedimentary rock; it reveals the history of life on Earth and the kinds of organisms that are alive in the past. Transitional fossil: a fossil that shows intermediary links between groups of organisms and shares characteristics common to two now separate groups. Vestigial structure: a structure that is a reduced version of a structure that was once functional in the organism’s ancestor. Biography: the study of past and present geological distribution of species population.

Homologous structures: structures that have similar structural elements and origin but may have a different function. Analogous structures: structures of organisms that do not have a common evolutionary origin but perform similar functions. Embryology (comparative embryology): the study of early stage, pre-birth stages of an organism’s development. Gene flow: the net movement of alleles from one population to another due to the migration tot individuals. Non-random mating: mating among individuals on the basis of mate selection for a particular phenotype or due to inbreeding.

Genetic rift: the change in frequencies of alleles due to chance events in a breeding population. Founder effect: a change in a gene pool that occurs when a few individuals start a new isolated population. Bottleneck effect: changes in gene distribution that result from a rapid decrease in population size. Stabilizing selection: natural selection that favors intermediate phenotypes and acts against extreme variants. Directional selection: natural selection that favors the phenotypes at one extreme over another, resulting in the distribution curve of phenotypes shifting in that direction of that extreme.

Disruptive (diversifying) selection: natural selection that favors extremes of a range of phenotypes rather than intermediate phenotypes; this type of selection can result in the elimination of intermediate phenotypes. Sexual selection: natural selection for mating based, in general, on competition between males and choices made by females. Speciation: the formation of new species from existing species. Pre-zygotic isolating mechanism: a barrier that either impedes mating between species or preventing fertilization of the eggs if individuals from different species attempt to mate; also ladle pre-fertilization barrier.

Post-zygotic isolating mechanism: a barrier that prevents hybrid zygotes from developing into viable, fertile individuals; also called post-fertilization barrier. Symmetric speciation: speciation in which populations within the same geographical areas diverge and become reproductively isolated. Allophonic speciation: speciation in which a population is split into two or more isolated groups by a geographical barrier; also called geographical speciation. Ecological niche: the ecological role and physical distribution of a species in its environment.

Adaptive radiation: the diversification of a common ancestral species into a variety of differently adapted species. Divergent evolution: a pattern of evolution in which species that were once similar to an ancestral species diverge, or become increasingly distinct. Convergent evolution: a pattern of evolution in which similar traits arise because different species have independently adapted to similar environmental conditions. Gradualism: a model of evolution that views evolutionary change as slow and steady, before and after a divergence.

Punctuated equilibrium: a model of evolution that views evolutionary history as long roods of stasis, or equilibrium, that are interrupted by periods of divergence. Unit 4: Animal Systems – Structure and Function Macromolecule: a very large molecule made up of smaller molecules that are linked together. Metabolism: the sum of all total chemical reactions that occur in an organism. Essential nutrient: a nutrient that cannot be made by the body, and must therefore be obtained from food. Macroeconomics: a simple sugar with three to seven carbon atoms. Disaccharide: a sugar made up of two macroeconomics molecules.

Polysaccharide: a large molecule made up of many linked macroeconomics molecules. Glycogen: a polysaccharide made up of glucose units. Lipid: an organic compound that does not dissolve in water, such as fat and oil. Amino acid: a building block of protein. Peptide bond: a bond that hold together the amino acids in a protein. Polypeptide: a linear chain of several amino acids linked by peptide bonds. Hydrolysis: a chemical reaction in which water breaks apart macromolecules into smaller molecules. Enzyme: a protein molecule that helps speed up important chemical reactions in the body.

Alimentary canal: a tube where food of processed, begins at mouth, ends at anus; digestive tract. Mechanical digestion: the physical breakdown of large pieces of food into smaller pieces in the mouth by the actions of teeth, beak, or other similar structures, and by contractions and churning motions in the stomach. Chemical digestion: the chemical breakdown of nutrient molecules into smaller molecules by enzyme action. Salivary glands: glands in the mouth that produce saliva to begin the chemical digestion of food. Saliva: a watery secretion in the mouth that begins the digestive process.

Esophagi: the muscular tube through which food passes from the mouth to the stomach. Peristalsis: a wave-like rise of muscular contractions in the esophagi. Gastric Juice: a mixture of hydrochloric acid, salts, enzymes, water, and mucus that is produced by glands in the stomach to help food digest. Chime: a thick liquid produced in the stomach and made of digested food combined with gastric Juice. Pepsin: an enzyme in gastric juice that helps break down proteins into polypeptides. Duodenum: a short, wide U-shaped section of the small intestine into which food passes from the stomach.

Vile: finger-like projection lining the surface of the small intestine that increase the surface area to improve the absorption of nutrients. Jejunum: the portion of the small intestine that follows immediately after the duodenum. Ileum: the portion of the small intestine that follows immediately after the Jejunum. Bile: a greenish- yellow fluid secreted by the liver that helps digest fat. Peptic ulcer: a sore in the lining of the stomach or duodenum, most commonly caused by infection with the bacterium Helicopter pylori.

Inflammatory bowel disease: the general name for a group of diseases that cause inflammation in the intestines. Crown’s disease: a form of inflammatory bowel disease that can affect any part of the alimentary canal from the mouth to the anus. Ulcerative colitis: a form of inflammatory bowel disease that attacks the colon. Hepatitis: inflammation of the liver, most commonly caused by a virus. Cirrhosis: the irreversible replacement of healthy liver tissue with non-functioning scar tissue; most commonly caused by excessive alcohol intake or hepatitis. Diabetes: a condition in which the body is unable to use glucose for energy.

Respiratory system: the group of organs that provides living things with oxygen from outside the body and disposes of waste products such as carbon dioxide. Respiration: all of the processes involved in bringing oxygen into the body, aging it available to each cell, and eliminating carbon dioxide as waste. Inspiration: the action of drawing oxygen-rich air into the lungs. Expiration: the action of releasing waste air from the lungs. Gas exchange: the transfer of oxygen from inhaled air into the blood, and of carbon dioxide from the blood into the lungs; it it’s the primary function of the lungs.

Ventilation: the process of drawing, or pumping, an oxygen-containing medium over a respiratory surface. Diffusion gradient: describes the relationship in which a dissolved substance moves from a region of high concentration to a region of low concentration. Diaphragm: a sheet f muscle that separates the thoracic cavity from the abdominal cavity. Spectrograph: a grape representing the amount (volume) and speed (rate tot tool) tot air that is inhaled and exhaled, as measured by a spectrometer. Tidal volume: the volume of air inhaled and exhaled during normal breathing.

Inspiration reserve volume: the volume of air that can be taken into the lungs beyond the regular tidal inhalation. Expiratory reserve volume: the volume of air that can be expelled from the lungs beyond the regular tidal exhalation. Vital capacity: the total maximum volume of air that can be moved into and out of the lungs during a single breath. Residual volume: the volume of air that remains in the lungs after a complete exhalation. Pharynx: the passageway Just behind the mouth that connects the mouth and nasal cavity to the larynx and esophagi.

Trachea: the tube that carries air from the nasal passages or mouth to the bronchi; also known as the windpipe. Glottis: the opening of the trachea through which air enters the larynx. Larynx: the structure between the glottis and the trachea that contains the vocal cords. Bronchus: the passageway that branches from the trachea to the lungs. Bronchiole: the passageway that branches from each bronchus inside the lung into increasingly smaller, thin-walled tubes. Alveolus: a tiny sac, with a wall that is one cell thick, found at the end of a bronchiole; respiratory gases are exchanged in this sac.

Hemoglobin: an iron-containing protein found in red blood cells, which binds to and transports oxygen from the lungs to the rest of the body. Tonsillitis: an infection caused by a virus or by bacteria. Laryngitis: an inflammation of the larynx that can cause the voice to become raspy and hoarse. Pneumonia: a disease that causes inflammation in one or both lungs; it is usually caused by a viral infection or a bacterial infection. Bronchitis: a respiratory disease that causes inflammation of the mucous membranes of the bronchi; it is classified as either acute (due to infection) or chronic (due to irritant).

Asthma: a lung disease that causes chronic inflammation of the lungs and overproduction of mucus in the lungs. Emphysema: a chronic respiratory disease that affects the ability of the lungs to expel air. Cystic fibrosis: a genetic disease that causes thick build-up of mucus in the lungs, resulting in infection, inflammation, and damage to the lung tissues. Carcinoma: a tumor made up of rapidly multiplying cells. Metastasis: the spread of cancerous cells room their original site to other parts of the body. Computed axial tomography: a specialized Z ray technique for imaging organs and other tissues in the body; also known as a CAT or CT scan.

Two-photon microscopy: a technique that uses photons to form images of living tissue up too depth of 1 mm. Bronchus’s: a technology for viewing, diagnosing, and treating the tissues and organs of the respiratory system. Circulatory system: the system that transports blood, nutrients, and waste around the body. Heart: the muscular organ that pumps blood via the circulatory system to the lungs and body. Blood vessel: a hollow tube that carries blood to and from body tissues. Blood: the bodily fluid in which cells are suspended.

Open circulatory system: a circulatory system in which vessels open into the animal’s body cavity. Closed circulatory system: a circulatory system in which the circulating blood is contained within vessels and kept separate from the interstitial fluid. Pulmonary artery: large blood vessel that carries blood directly from the heart to other arteries. Pulmonary vein: blood vessel that carries blood from the lungs to the heart. Aorta: an artery that carries b y directly trot the heart to other arteries. Therapeutically valve: a valve in the heart between the ventricle and atrium.

Seminar valve: a valve between the ventricle and the large arteries; it carries blood away from the heart. Pulmonary circulation: the path that blood follows from the heart to the lungs and back to the heart. Systemic circulation: the path that blood follows from the heart to the body and back to the heart. Cardiac circulation: the movement of blood through the heart tissues. Visitation: the widening of the blood vessels. Vasoconstriction: the narrowing of the blood vessels. Senatorial (AS) node: the modified heart cells in the right atrium that bounteously generate the rhythmic signals that caused the atria to contract.

Therapeutically (VA) node: the specialized heart cells near the Junction of the atria and ventricles that cause the ventricles to contract. Electrocardiogram (EGG): a record of the electrical impulses generated by a beating heart. Blood pressure: the force that blood exerts against the walls of blood vessels. Systolic pressure: the pressure generated in the circulatory system when the ventricles contract and push blood from the heart. Diastolic pressure: the pressure generated in the circulatory system when the ventricles fill with blood. Sphygmomanometer: a medical device used to measure blood pressure.

Cardiac output: the volume of blood pumped out by the heart in mini. Stroke volume: the volume of blood pumped out of the heart with each heartbeat. Arteriosclerosis: general term for several conditions in which the walls of the arteries thicken and lose elasticity. Angioplasty: a surgical procedure used to open up a clogged artery. Coronary bypass: a surgical procedure in which blood flow is re-routed around blocked arteries. Aneurysm: a bulge in an artery or heart chamber caused by a weakened area of the heart muscle f arterial wall. Arrhythmia: an irregularity in the speed or rhythm of the heartbeat.

Pacemaker: a device that sends electrical impulses that control the rate of the heartbeat. Congenital heart defect: a heart defect that is present from birth. Chemic stroke: a stroke caused by a clot in a blood vessel, blocking flow to the brain. Hemorrhagic stroke: a stroke caused by the bursting of a blood vessel in the brain, which causes blood to leak into the surrounding brain tissue. Hemophilia: an inherited disorder in which the blood does not clot normally. Leukemia: cancer of the white blood cells. Semitransparent: a transplant of tissues and organs from one species to another.

Nanotechnology: technology that uses microscopic structures on the scale of molecules. Unit 5: Plants – Anatomy, Growth and Function Photosynthesis: a series of chemical reactions that converts energy from sunlight into chemical energy stored in molecules. Cellulose: a large carbohydrate molecule. Agriculture: farming or forestry practices that produce food and goods. Food security: the state where all people, at all times, have access to enough safe and nutritious food to meet their dietary needs and preferences and allow them to lead