Multicellular eukaryotes start as single-celled embryo and grow thru cell division. Chromosomes-carry hereditary material/instructions for building + operating cell. Made up of single dna double helix wrapped around proteins. Gamete-haploid reproductive cell, fuse w/ another haploid cell to form zygote (eg. egg and sperm cells) Somatic cells-body cells (cell in multicellular org. that isn"t sperm/egg) Meiosis/reduction division-hereditary material in parent cell reduced by half, occurs in animals just to form gametes. Mitosis-daughter cells genetically identical to parent cell (hereditary material is constant), followed by Cytokinesis ( cell movement )-cytoplasm divides into the 2 daughter cells. Gene-segment of dna that codes for certain protein or rna in cell. Mitotic (m)-dividing phase (m + c) where copied chrom. given to daughter cells, no replication. Interphase (between phase)-nondividing (cells spend most time here, chro. replication) Cell cycle-starts with formation of eukaryotic cell to time it undergoes cell division.