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| a special type of cell division necessary for sexual reproduction. |
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| a mature sexual reproductive cell, as a sperm or egg, that unites with another cell to form a new organism |
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| is the union of a human egg and sperm, usually occurring in the ampulla of the uterine tube. |
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| the cell produced by the union of two gametes |
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| chromosome pairs of the same length, centromere position, and staining pattern, with genes for the same characteristics at corresponding loci. |
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| cells have two homologous copies of each chromosome |
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| is the number of chromosomes in a gamete. |
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| the phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes including preparation for cell division |
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| DNA is exchanged between homologous chromosomes in a process called homologous recombination |
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| Homologous pairs move together along the metaphase plate: As kinetochore microtubules from both centrioles attach to their respective kinetochores, the homologous chromosomes align along an equatorial plane that bisects the spindle, due to continuous counterbalancing forces exerted on the bivalents by the microtubules emanating from the two kinetochores of homologous chromosomes |
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| microtubules shorten, severing the recombination nodules and pulling homologous chromosomes apart |
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| The microtubules that make up the spindle network disappear, and a new nuclear membrane surrounds each haploid set. The chromosomes uncoil back into chromatin. |
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| the pairing of two homologous chromosomes that occurs during meiosis |
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| A four-part structure that forms during the prophase of meiosis and consists of two homologous chromosomes, each composed of two sister chromatids. |
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| the disappearance of the nucleoli and the nuclear envelope again as well as the shortening and thickening of the chromatids. Centrioles move to the polar regions and arrange spindle fibers for the second meiotic division. |
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| the centromeres contain two kinetochores that attach to spindle fibers from the centrosomes (centrioles) at each pole. The new equatorial metaphase plate is rotated by 90 degrees when compared to meiosis I, |
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| where the centromeres are cleaved, allowing microtubules attached to the kinetochores to pull the sister chromatids apart. |
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| is marked by uncoiling and lengthening of the chromosomes and the disappearance of the spindle. Nuclear envelopes reform and cleavage or cell wall formation eventually produces a total of four daughter cells, each with a haploid set of chromosomes. |
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| is an exchange of genetic material between homologous chromosomes. |
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| The temporary union of two bacterial cells during which one cell transfers part or all of its genome to the other. |
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| the failure of chromosome pairs to separate properly during cell division. |
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