| Term | Definition |
| cell cycle | cycle in which cells gorw and carry out all f the functions required by by living organisms and then divide, forming two identical daughter cells |
| cell division | process in which one cell divides into two identical daughter cells |
| daughter cells | two identical cells produced during cell division |
| interphase | the period of cell growth and preparation for cell division, subdivided into three phases G1, S1 and G2 |
| G1 Phase | phase of he cell cycle in which the cell takes in nutrients, like sugars, that are used for energy and growth, and repair of damaged organelles |
| G2 Phase | phase of the cell cycel in which extra organelles and cytoplasm are produced in preparation for cell division |
| S Phase | The phase in which DNA is replicated |
| chromatids | the two identical sister chromosomes that attach at the centromere when chromosomes become visible during the early phase of cell division |
| centrioles | organelles that aid in the division of genetic material during cell division |
| M phase | the time in the life cycle of a cell that includes cell divisioon |
| mitosis | the process of cell division by which the nucleus divides, typically consisting of 4 phases which results in the formation of 2 identical daughter cells |
| cytokinesis | the division of the cytoplasm and organelles |
| prophase | the first phase of mitosis, when the chromatin condnses to from the chromosomes |
| centromere | what each sister chromatid is attached to |
| spindle | fibers that organize themselves around the centrioles and attach themselves to the centromeres during mitosis |
| metaphase | the second phase of mitosis in which the nuclearmembrane has completely brokend down and the chromosomes have lined up along the middle of the cell |
| anaphase | the third phase of cell division in which the sister chromatids are pulled apart by the spindle fibers and begin to move to opposite poles of the cell |
| telophase | the fourth phase of mitosis in which the chromosomes reach opposite poles of the cell and begin to unravel |
| cell plate | duing mitosis of plant cells a disk that froms between the two nuclei |
| somatic cell | body cell |
| meiosis | process of cell division in sexually reproducing organisms that reduces the number of chromosomes in reproductive cells from diploid to haploid |
| gamete | a sperm or egg cell |
| zygote | cell formed by the union of two gametes |
| fertilization | the union of male and female gametes to form a zygote |
| haploid number | number of chromosomes found in a cell cell---- 1/2 he number found in a body cell |
| diploid number | the total number of paired chromosomes found in each somatic cell in humans the number is 46 |
| homologous chromosomes | paired chromosomes that separate during meiosis |
| synapsis | in meiosis the pairing up of homologous chromosomes |
| crossing over | during meiosis when chromosom segments are broken off and exchanged |
| independent assortment | during meiosis the random separating of homologous pairs of chromosomes |