chromatid - either of the two strands of a chromosome which contain genes for making proteins chromatin - the DNA and proteins that make up a eukaryotic cell's chromosomes chromosome - a coil of proteins and DNA which are made up of two chromatids crossing over - the exchange of genetic material betwee homolgous chromosomes during synapsis in prophase I of meiosis cytokinesis - the process in which a cell's cytoplasm divides cytoplasm - the gel-like substance which contains a cell's organelles and nucleus daughter cell - a cell that is the offspring of a cell which has gone through meiosis or mitosis ("daughter" does not indicate that the cells are female) diploid cell - a cell containing two sets of chromosmes (2n), one set inherited from each parent eukaryotic cell - a type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles gamete - a haploid egg or sperm cell which unite to form a diploid zygote gene - a unit of consisting of a specific DNA or RNA sequence haploid cell - a cell containing only one set of chromosomes (n) homologous chromosomes - chromosome pairs of the same length that have genes for the same characteristics (one homologous chromosome is inherited from the mother, the other from the father) synapsis - the pairing of homologous chromosomes during prophase I of meiosis tetrad - a pair of homologous chromosomes that have replicated and come together (consists of four chromatids)