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Definition
| The third phase of mitosis; at the metaphase-anaphase transition, centromeres divide and the two chromatids of a chromosome become independent chromosomes. During this phase, the two are pulled to opposite poles of the spindle by spindle microtubules. |
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| The life cycle of a cell. |
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| During cell division, the new cell wall forms inside a large vesicle surrounded by phragmoplast microtubules. The wall, vesicle, and phragmoplast together constitute this region. |
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| Region of a chromosome that holds the two chromatids together prior to anaphase of mitosis or anaphase II of meiosis. Spindle microtubules attach to this region and move the chromosomes during division. |
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| A portion of a chromosome consisting of one DNA double helix and its histones. Before S phase, each chromosome consists of just one of these, but after DNA replication in S phase, each chromosome consists of two of these. |
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| Each nuclear DNA double helix is complexed with histone into this structure, which consists of one (pre-S phase) or two (post-S phase) chromatids plus a centromere. |
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| Stage of prophase I in which chromosomes become shorter and thicker; also called pachytene |
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| During prophase I of meiosis, after homologous chromosomes have paired and a synaptonemal complex has formed, the DNA of the homologs breaks and the end of each homolog is attached to the other homolog, resulting in two new chromosomes. |
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Definition
| Division of the protoplasm of a cell, as opposed to nuclear division, karyokinesis. |
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| Refers to two full sets of chromosomes in each nucleus, as typically found in sporophytes and zygotes |
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| Part of interphase of the cell cycle that is the interval between cell division and the synthesis of DNA in the nucleus. This is often the longest phase, during which the nucleus actively directs cytoplasmic metabolism. |
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Definition
| Part of interphase of the cell cycle that is the interval between the synthesis of DNA and the beginning of nuclear division. |
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| A haploid sex cell, such as an egg or sperm. |
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| All the alleles of an organism. |
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| Refers to one full set of chromosomes per nucleus |
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| A set of basic nuclear proteins that complex together and with DNA, first forming nucleosomes and then complexing further into chromosomes. |
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| In a diploid nucleus, each type of chromosome is present as a pair, one inherited paternally, the other maternally. |
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Definition
| The portion of the cell cycle that is not cell division; includes phases G1, S, and G2. |
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Term
| karyokinesis (pl.: karyokineses) |
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Definition
| Division of a nucleus, as opposed to cell division, cytokinesis. The two types of this division are mitosis and meiosis. |
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Definition
| In a chromosome, it is the point at which spindle microtubules attach to the centromere. |
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| Reduction division, a process in which nuclear chromosomes are duplicated once but divided twice, such that the resulting nuclei each have only one half as many chromosomes as the mother cell. |
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| The second phase of mitosis during which chromosomes move to the center of the spindle. |
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| The region in the center of the spindle where chromosomes become aligned during nuclear division. |
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| Duplication division -- a type of nuclear division (karyokinesis) in which nuclear chromosomes are first duplicated, then divided in half, one daughter nucleus receiving one set, the other daughter nucleus receiving the other set. |
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Definition
| During cell division, this is a set of short microtubules oriented parallel to the spindle microtubules; it catches dictyosome vesicles and guides them to the site where the new cell wall (cell plate) is forming. |
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Definition
| The initial phase of mitosis during which the nucleolus and nuclear membrane break down, chromosomes begin to condense, and the spindle begins to form. |
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old synonym for interphase |
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Definition
| The synthesis phase of the cell cycle, during which nuclear DNA is replicated (synthesized). |
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| The framework of microtubules that pulls the chromosomes from the center of the cell to the poles during nuclear division. |
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Definition
| Microtubules extending from one pole to the center of the cell, where their ends overlap with the ends of microtubules extending from the opposite end of the cell. |
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Definition
| The pairing of homologous chromosomes during zygotene of prophase I of meiosis. |
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| The fourth and last phase of mitosis, during which the chromosomes decondense, the nucleolus and nuclear envelope reform, the spindle depolymerizes, and the phragmoplast appears. |
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| The diploid cell formed as the result of the fusion of two gametes. |
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