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Thick middle muscle layer of the heart; pumps blood through the circulatory system


Upper chamber of the heart that recieves and holds blood that is about to enter the ventricle


Lower chamber of the heart that pumps blood out of the heart

Pulmonary Circulation

Pathway of circulation between the heart and the lungs

Systemic Circulation

Pathway of circulation between the heart and the rest of the body


Flap of connective tissue between an atrium and a ventricle, or in a vein, that prevents backflow of blood


Small group of cardiac muscle cells in the right atrium that "set the pace" for the heart as a whole


A large blood vessel in mammals through which blood travels from the left ventricle to all parts of the body except the lungs


Large blood vessel that carries blood from the heart to tissues of the body


Smallest blood vessel


A blood vessel that returns blood to the heart


Condition in which fatty deposits called plaque build up on the inner walls of the arteries


Straw colored fluid that makes up 55%of blood; consists of about 90% water and 10% of dissolved gases, salts, nutrients, enzymes, hormones, waste products and plasma proteins


Iron containg protein in red blood cells that transports oxygen from the lungs to the tissues of the body


Type of white blood cell that produces antibodies that help destroy pathogens


Cell fragment released by bone marrow that helps in blood clotting


Fluid lost by the blood in surrounding tissue


Muscular tube at the end of the gastrovascular cavity, or throat, that connects the mouth with the rest of the digestive tract and serves as a passageway for food and air


Windpipe; tube through which air moves


Structure in the throat containing the vocal cords


Passageway leading the trachea to a lung


Large, flat muscle at the bottom of the chest cavity that helps with breathing


Stimulant drug in tabacco that increase heart rate and blood pressure


Disease in which tissues of the lungs loose elasticity, which makes breathing more difficult


The strength and vitality required for sustained physical or mental activity.


Amount of energy needed to raise the temperature of 1gram of water by 1 degrees Celsius

ATP (Adenosine Triphosphate)

One of the principal chemical compounds that living things use to store and release energy


First step in releasing energy of glucose in which a molecule of of gluecose is broken into two molecules of pyruvic acid

Latic Acid Fermentation

Biological process by which sugars such as glucose, fructose, and sucrose, are converted into cellular energy


Process that requires oxygen


Process that does not require oxygen

Kreb's Cycle

Second stage of cellular respiration, in which pyruvic acid is broken down into CO2 in a series of energy-extracting reactions

Electron Transport Chain

A series of proteins in which the high-energy electrons from the Krebs Cycle are used to convert ADP into ATP


Electron carrier involved in glycolysis

ATP Synthase

Large protein that uses energy from H+ ions to bind ATP and a phosphate group together to make ATP

Cell Division

Process by which a cell divides into two new daughter cells


Part of the eukaryotic cell division during which the cell nucleus divides


Division of the cytoplasm during cell division


Threadlike structures within the nucleus containg the genetic information that is passed from one generation to the next


granular material visible within the nucleus


Period of the cell cycle between cell divisions

G1 Phase

Period where cells do most of their growing before cell divsion

S Phase

Period where cells are replicated before cell division

G2 Phase

Period where cells are checked before going through cell division


First and longest phase of mitosis, during which the chromosomes become visable and the centrioles seperate and take up positions on the opposite sides of the nucleus


Second phase of mitosis, during which the chromosomes line up across the center of the cell


Third phase of mitosis, during which chromosomes seperate and move toward opposite poles


Fourth and final phase of MITOSIS, during which the chromosmes begin to disperse into a tangle of the dense material


fanlike microtube structure that helps seperate the chromosomes during mitosis


One of the two tiny structures in the cytoplasm of animals near the nuclear envelope

Cell Plate

Wall between the two new cells forming in mitosis


Scientific study of heredity


process in sexual reproduction in which male and female reproductive cells join to form a new cell


Term used to describe organisms that produce offspring identical to themselves


Specific characteristic


Offspring of crosses between parents with different traits


Sequences of DNA that codes for a protein and thus determines a trait


One of a number of forms of a gene


Seperation of alleles during gamete formation


Sex cell


The likelyhood that something will occur

Punnet Square

Diagram showing the gene combinations that might result in a genetic cross


Organism that has two identical alleles for a trait


Organism that has two different alleles for the same trait


Physical characteristics of an organism


Genetic makeup of an organism

Independent Assortment

Independent segregation of genes during the formation of gametes

Incomplete Dominance

Situation in which one allele is not completely dominant over the other


Situation in which both alleles contribuate to the phenotype of the organism

Multiple Alleles

Three or more alleles for the same gene

Polygenic Traits

traits controlled by two or more genes


Term used to refer to chromosomes that each have a corresponding chromosome from the opposite-sex parent


Term used to refer to a cell that contains both sets of homologous chromosomes


Term used to refer to a cell that has a single set of chromosomes, therefore a single set of genes


Process by which the number of chromosomes per cell is cut in half through the seperation of homologous chromosomes in a diploid cell


Structure containing 4 chromatids that forms during meiosis


Process in which homologous chromosomes exchange portions of their chromatids during meiosis

Gene Map

Diagram showing the relative locations of each known gene on a particular chomosome


Set of photographs of chromosomes grouped in order in pairs

Sex Chromosome

One of the two chromosomes that determine and individual's sex; Male:XY Female:XX


Chromosome that is not a sex chromosome


Chart that shows the relationships within a family

Sex-Linked Gene

Gene located on the X of Y chromosome


Chromosomes fail to seperate fully in meiosis


Monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

Base Pairing

Principle that bonds in DNA can form only between adenine and thymine and guanine and cytosine


Globular protein molecule around which DNA is tightly coiled in chromatin


Copying process by which a cell duplicates its DNA

DNA Polymerase

Enzyme that "proofreads" new DNA strands, helping to ensure that each molecule is a nearly perfect copy of the original DNA

Messenger RNA

RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell

Ribosomal RNA

Type of RNA that makes up the major part of ribosomes

Transfer RNA

Type of RNA molecule that transfers amino acids to ribosomes during protein synthesis


Process in which part of the nucleotide sequence of DNA is copied into a complemantary strand of RNA

RNA Polymerase

Enzyme similar to DNA polymerase that binds to DNA and seperates the DNA strands during transcription


Region of DNA that indicates to an enzyme where to bind to make RNA


Intervening sequence of DNA; does not code for a protein


Expressed sequence of DNA; codes for a protein


Three nucleotide sequence on messenger RNA that codes for a single amino acid


Decoding of mRNA message into a polypeptide chain


Group of three bases on a tRNA molecule that are complemantary to an mRNA codon


Change in a kind of organism over time


A well-tested explanation that unifies a broad range of observations


Preserved remains or evidence of an ancient organism

Natural Selection

Process by which individuals that are better suited to their environment survive and reproduce more successfully; also called survival of the fittest

Artificial Selection

Selection by humans breeding of usefult raits from the natural variation among among different organisms


Ability of an organism to survive and reproduce in its environment


inherited characteristic that increases an organisms chance of survival

Struggle for Exsistence

Competition among members of a species among food, living space, and other necessities of life

Survival of the Fittest

Process by which individuals that are better suited to their environment survive and reproduce more successfully; also called natural selection

Descent with Modification

Principle that each living species has descended, with changes, from a species over time

Common Descent

Principle that all living things have a common ancestor

Homologous Structures

Structures that have different mature forms in different organisms but develope from the same embryonic tissue


The belief in or the policy of advancing toward a goal by gradual, often slow stages

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