Term
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Definition
| number, size and form of chromosomes in actively dividing cells |
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Term
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Definition
| Cell divides into two cells identical to mother cell |
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Term
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Definition
-Phase of the cell cycle during which the chromosomes are de-condensed and found in the nucleus
-When G1, S, G2 phases happen |
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Term
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Definition
-Cell accumulates molecular changes that cause progression through the cell cycle
-Passes restriction point where cell is committed to enter S phase
-If cell is not ‘in shape’ to divide, division stops at this step |
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Term
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Definition
-Chromosomes replicate
-After replication, 2 copies stay joined to each other and are called sister chromatids
-Human cells now temporarily have 92 chromatids |
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Term
| G2 (interphase) - Mitosis |
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Definition
| -Cell synthesizes proteins needed during mitosis and meiosis |
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Term
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Definition
-Chromosomes have already replicated to produce 12 chromatids, joined as six sister pairs
-Nuclear membrane dissociates into small vesicles
-Chromatids condense into highly compacted structures (readily visible by light microscopy) |
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Term
| Prometaphase (3) - Mitosis |
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Definition
-Nuclear envelope completely fragments
-Mitotic spindle is fully formed during this phase
-Centrioles move apart and demarcate the two poles
-Spindle fibers interact with sister chromatids
-Two kinetochores on each pair of sister chromatids are attached to kinetochore microtubules from opposite sides |
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Term
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Definition
-Pairs of sister chromatids are aligned along a plane halfway between the poles called the metaphase plate (organized into a single row)
-When alignment is complete, the cell is in metaphase |
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Term
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Definition
-Connections between the pairs of sister chromatids are broken
-Each chromatid , now an individual chromosome, is linked to only one of the two poles by one or more kinetochore microtubules
-Kinetochore microtubules shorten, pulling chromosomes toward the pole to which attached
-Two poles more farther apart as overlapping polar microtubules lengthen (push on each other) |
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Term
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Definition
-Chromosomes have reached their respective poles and decondense
-Nuclear membranes now re-form to produce two separate nuclei |
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Term
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Definition
-In most cases mitosis is quickly followed by cytokinesis
-Two nuclei are segregated into separate daughter cells
-Process of cytokinesis is quite different in animals and plants
-Animals - cleavage furrow constricts like a drawstring to separate cells
-Plants - cell plate forms a cell wall between the two daughter cells (made of vesciles from golgi apparatus) |
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Term
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Definition
-responsible for organizing and sorting the chromosomes during mitosis
-Astral - position spindle in cell
-Polar - Separate to poles
-Kinetochore - attached to kinetochore bound to centromeres of each chromosome |
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Term
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Definition
-Sexual reproduction requires a fertilization event in which two haploid gametes unite to create a diploid cell called a zygote.
-A process by which haploid cells are produced from a diploid cell. (cells going through meiosis must go through G1, S and G2 before beginning) |
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Term
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Definition
| Homologous pairs of chromatids associate together and Cross Over (swap pieces of genetic material). |
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Term
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Definition
| After crossing over, chromosomes stay attached at crossing over site called a chiasma |
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Term
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Definition
Physical exchange between chromosome pieces of the bivalent complex. (increases genetic variation).
Process is carefully controlled by cells. |
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Term
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Definition
| Replicated chromosomes condense and bivalents form as the nuclear membrane breaks down. |
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Term
| Prometaphase 1 - Meiosis 1 |
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Definition
| Spindle apparatus complete and the chromatids are attached to kinetochore microtubules. |
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Term
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Definition
| Bivalents are organized along metaphase plate. |
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Term
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Definition
-Connections between bivalents break, but not the connections that hold sister chromatids together.
-Each joined pair of chromatids migrates to the pole. |
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Term
| Telophase 1 and cytokinesis - Meiosis 1 |
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Definition
| Sister chromatids have reached their respective poles and decondense. Nuclear membranes form. |
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Term
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Definition
-No S phase between Meiosis 1 & 2.
-Sorting events are similar to mitosis, but concludes with haploid cells because there was no S-phase after meiosis 1. |
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Term
| # of chromosomes - Humans |
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Definition
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Term
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Definition
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Term
| # of chromosomes - Fruit Fly |
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Definition
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Term
| # of chromosomes - Tomato |
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Definition
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Term
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Definition
| Stains chromosomes for G banding identification |
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Term
| Location of a Metacentric centromere is where? |
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Definition
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Term
| Location of a Submetracentric centromere is where? |
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Definition
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Term
| Location of a Acrocentric centromere is where? |
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Definition
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Term
| Location of a Telocentric centromere is where? |
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Definition
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Term
| Chromosomal mutation - Duplication |
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Definition
| Selection occurs 2 or more times in a row. |
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Term
| Chromosomal mutation - Inversion |
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Definition
| Change in direction along a single chromosome |
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Term
| Chromosomal mutation - Translocation |
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Definition
-One segment becomes attached to another chromosome.
-Simple or reciprocal. |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
-Alteration of particular chromosomes.
-Total number not an exact multiple of a set.
-(if happens in eukaryotes is detrimental)
-(5-10% of all human eggs result in and embryo with abnormal chromosome number) |
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Term
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Definition
-Normal 2 copies of a chromosome plus a 3rd.
-2n+1 |
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Term
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Definition
-Missing one of the normal copies of a chromosomes
-2n-1 |
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Term
| Nondisjunction (chromosomes) |
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Definition
-Chromosomes do not sort properly during cell division.
-During meiosis, can produce gametes with too many chromosomes of too few. |
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Definition
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