| A | B |
|---|
| mitosis | division of the nucleus |
| cytokinesis | division of the cytoplasm |
| sister chromatids | a chromosome with its identical copy |
| centromere | the location at which sister chromatids are attached to one another |
| cell cycle | the life of the cell from the time it is first formed from a dividing parent cell until it then divides. |
| interphase | Collectively, the G<SUB>1</SUB>, S and G<SUB>2</SUB> phases; the period of time when the cell is not dividing. |
| cancer | the consequence of uncontrolled cell division |
| cell cycle regulators | proteins that signal a cell to start/stop, speed up/slow down or prevent cell division. |
| asexual reproduction | offspring are produced by one parent; no genetic variation in offspring. |
| sexual reproduction | offspring are the product of two parents; offspring are genetically different from each other and from the parents. |
| gametes | sex cells; sperm and egg |
| zygote | an egg that has been fertilized by a sperm. |
| gene | a segment of DNA that codes for a protein |
| homologous chromosomes | the two copies of each chromosome; one from the mother and one from the father. |
| diploid | 2 of each kind of chromosome |
| haploid | 1 of each kind of chromosome |
| meiosis | cell division in which the number of chromosomes in each daughter cell halved due to the separation of homologous chromosomes. |
| tetrad | 4 chromatids; 2 sister chromatids from the mother paired with the corresponding 2 sister chromatids from the father. |
| crossing over | the exchange of genes between segments of homologous chromosomes during Meiosis |
| chromosome | a structure made of DNA and proteins; carries genetic information |
| genetic recombination | the rearrangement of DNA sequences by the breakage and rejoining of chromosome segments; occurs during crossing over |
| autosomes | any chromosome that is not a sex chromosome |
