Meiosis (AP Bio) Flashcards
Meiosis has two divisions of the nucleus- meiosis I and meiosis II. 4 haploid cells are created as a result.
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| 12846668483 | Prophase I | Homologous pairs form, crossing over occurs |  | 0 |
| 12846668484 | Metaphase I | The pairs of homologous chromosomes line up in the center of the cell. |  | 1 |
| 12846668485 | Anaphase I | Homologous chromosomes are pulled to opposite ends of the cell. Note that chromatids do not separate - each duplicated chromosome still has two chromatids. |  | 2 |
| 12846668486 | Telophase I | The cytoplasm divides and two new cells form. Each new cell has one duplicated chromosome from each similar pair. |  | 3 |
| 12846668487 | Prophase II | The chromosomes and spindle fibers reappear in each new cell but do not cross over or duplicate again. |  | 4 |
| 12846668488 | Metaphase II | The chromosomes move to the centre of the cell. Each centromere attaches to two spindle fibres instead of one. |  | 5 |
| 12846668489 | Anaphase II | The centromere divides. The chromatids seperate and move to opposite ends of the cell. Each chromatid is now an individual chromosome. |  | 6 |
| 12846668490 | Telophase II | The spindle fibres disappear, and a nuclear membrane forms around each set of chromosomes; cytokinesis begins which results in 4 daughter cells. |  | 7 |
| 12846668491 | Homologous chromosomes | Chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis. |  | 8 |
| 12846668492 | Crossing Over | Process in which homologous chromosomes exchange portions of their chromatids during meiosis. This is important because it increases genetic variation in the offspring. |  | 9 |
| 12846668493 | Interphase I | Chromosomes replicate in preparation for meiosis. At this point they are long and thing and called "chromatin". |  | 10 |
| 12846668494 | Haploid | A cell that contains only one set of chromosomes instead of the normal pair. Gametes, which are sex cells like sperm and eggs, are haploid cells. |  | 11 |
| 12846668495 | Diploid | A cell that contains two sets of chromosomes; one inherited from the mother and one inherited from the father. Most body cells (nerve, brain, muscle, skin, etc.) are considered diploid cell. |  | 12 |
| 12846668496 | Sperm | Male gamete (sex cell) |  | 13 |
| 12846668497 | Egg | Female gamete (sex cell) |  | 14 |
| 12846668498 | Gamete | Sex cells, that contain half of the genetic information of the parent organism. |  | 15 |
| 12846668499 | Meiosis | A process in cell division during which the number of chromosomes decreases to half the original number. |  | 16 |
| 12846668500 | 46 | number of chromosomes present in normal humans | 17 | |
| 12846668501 | somatic cells | body cells, they are also diploid aka contain both sets of chromosomes | 18 | |
| 12846668502 | XY | the genetic chromosomes for a male | 19 | |
| 12846668503 | XX | the genetic chromosomes for a female | 20 | |
| 12846668504 | Advantages of meiosis for sexual reproduction | more genetic diversity or genetic variation in reproductive cells and thus in offspring which generally leads to an increased chance of survival | 21 | |
| 12846704238 | Independent Assortment | the random distribution of the pairs of genes on different chromosomes to the gametes |  | 22 |
| 12846717412 | Synapsis | the pairing of homologous chromosomes during meiosis, forms a tetrad | 23 | |
| 12846721534 | 92 | the number of chromatids present at the end of prophase I of meiosis | 24 |