| Term | Definition |
|---|
| Mitosis | part of eukaryotic cell division in which the cell nucleus divides |
| Centromere | area where chromatids of a chromosome are attached |
| Genetics | scientific study of heredity |
| Hybrid | offspring of crosses between parents of different traits |
| Segregation | separation of alleles during gamete formation |
| Homozygous | term used to refer to an organism that has two identical alleles for a particular trait |
| Genotype | genetic makeup of an organism |
| Codominance | situation in which both alleles of a gene contribute to a the phenotype of an organism |
| Diploid | term used to refer to a cell that contains both sets of homologous chromosomes |
| Tetrad | structure containing four chromatids that forms during meiosis |
| Bacteriophage | virus that infects bacteria |
| Chromatin | granular material visible within the nucleus; consists of DNA tightly coiled around proteins |
| DNA Polymerase | enzyme that proofreads new DNA strands, ensuring that each new molecule is a nearly perfect copy of the original DNA |
| Transfer RNA | type of RNA molecule that transfers amino acids to ribosomes during protein synthesis |
| Promoter | region of DNA that indicates to an enzyme where to bind to make RNA |
| Codon | three-nucleotide sequence on messenger RNA that codes for a single amino acid |
| Mutation | change in DNA sequence that affects genetic information |
| Evolution | change in a kind of organism over time; process by which modern organisms have descended from ancient ones |
| Adaptation | inherited characteristics that increases an organism's chance of survival |
| Vestigial Organ | organ that serves no useful function in an organism |
| Stabilizing Selection | form of natural selection that occurs when individuals near the center of a distribution curve have a higher fitness than those at either end |
| Speciation | formation of a new species |
| Pedigree | chart that shows the relationships within a family |
| Follicle | cluster of cells surrounding a single egg in the human female reproductive system |
| Corpus Luteum | name given to a follicle after ovulation because of its yellow color |
| Cytokinesis | division of cytoplasm during cell division |
| Centriole | one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope |
| Fertilization | process in sexual reproduction in which the male and female reproductive cells join to form a new cell |
| Gene | sequence of DNA that codes for a protein and thus determines a trait |
| Gamete | specialized cell involved in reproduction |
| Heterozygous | term used to refer to an organism that has two different alleles for the same trait |
| Independent Assortment | independent segregation of genes during the formation of gametes |
| Multiple Alleles | three or more alleles of the same gene |
| Haploid | term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of genes |
| Crossing Over | process in which homologous chromosomes exchange portions of their chromatids during meiosis |
| Nucleotide | monomer of nucleic acid, made up of a 5-carbon sugar, phosphate group, and a nitrogenous base |
| Histone | globular protein molecule around which DNA is tightly coiled in chromatin |
| 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 |
| Transcription | process in which part of the nucleotide sequence of DNA is copied into a complementary strand of RNA |
| Intron | intervening sequence of DNA; does not code for a protein |
| Translation | decoding of an mRNA message into a polypeptide chain |
| Point Mutation | mutation that affects a single nucleotide, usually by substituting one nucleotide for another |
| Fossil | preserved remains or evidence of an ancient organism |
| Natural Selection | process by which individuals that are better suited for their environment survive and reproduce most sucessfully |
| Gene Pool | combined genetic information of all the members of a particular population |
| Disruptive Selection | form of natural selection that occurs when individuals at the upper and lower ends of a distribution curve have a higher fitness that those near the middle |
| Index Fossil | distinctive fossil used to compare relative ages of fossils |
| Sex-Linked Gene | gene located on the X or Y chromosome |
| Ovulation | process in which an egg is released from the ovary |
| Menstruation | phase of menstrual cycle during which the lining of the uterus, blood, and the unfertilized egg are discharged through the vagina |
| Chromatid | one of two identical "sister" parts of a duplicated chromosome |
| Spindle | fanlike microtubule structure that helps separate the chromosomes during mitosis |
| Trait | specific characteristic that varies from one individual to another |
| Allele | one of a number of different forms of a gene |
| Probability | likelihood that a particular event will occur |
| Phenotype | physical characteristics of an organism |
| Incomplete Dominance | situation in which one allele is not completely dominate over another |
| Homologous | term used to refer to a chromosome that each have a corresponding chromosome from the opposite sex parent |
| Meiosis | process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell |
| Transformation | process in which one strand of bacteria is changed by a gene or genes from another strain of bacteria |
| Base Pairing | principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine |
| Replication | copying process by which a cell duplicates its DNA |
| Ribosomal RNA | type of RNA that makes up the major part of ribosomes |
| RNA polymerase | enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription |
| Exon | expressed sequence of DNA; codes for a protein |
| Anticodon | group of three bases on a tRNA molecule that are complementary to an mRNA codon |
| Frameshift Mutation | mutation that shifts the reading frame of the genetic message by inserting or deleting a nucleotide |
| Artificial Selection | selection by humans for breeding of useful traits from the natural variation among different organims |
| Homologous Structure | structure that has different mature forms but develop from the same embryonic tissue |
| Directional Selection | from of natural selection that occurs when individuals at one end of a distribution curve have a higher fitness than those in the middle or the other end of the curve |
| Genetic Drift | random change in allele frequencies that occur in small populations |
| Taxonomy | discipline of classifying organisms and assigning each organism a universally accepted name |
| Puberty | period of rapid growth and sexual maturation during which the reproductive system becomes fully functional |
| Menstrual Cycle | cycle during which an egg develops and is released from an ovary and the uterus is prepared to receive a fertilized egg |
| Zygote | fertilized egg |
Combine with other sets
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