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Definition
| special cell division that gives rise to gametes |
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Term
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Definition
| divides a eukaryotic cell's genetic information into 2 daughter cells, mitosis refers to the division of the atual nucleus |
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Term
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Definition
| DNA and associated proteins in the nucleus |
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Term
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Definition
| a single continuous molecule of DNA wrapped around protein. Eukaryotic cells contain multiple linear chromosomes. |
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Definition
| one of two identical attached copies of a replicated chromosome |
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Definition
| a small region of a chromosome where sister chromatids attach to each other |
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Definition
| the splitting of the cell itself |
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Definition
G1: normal cell function and growth
S phase: DNA replication
G2: additional growth and preparation for division |
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Term
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Definition
| chromosomes condense and become visible in nucleus. Spindles form and centrosomes move to opposite ends of cell |
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Definition
| mitotic spindle aligns chromosomes along cell's equator |
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Term
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Definition
| centromeres split as sister chromatids separate and move to opposite poles of cell |
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Term
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Definition
| nuclear envelope and nucleolus form at each pole, chromosomes decondense. spindles disappear. |
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Term
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Definition
| starts with cleavage furrow/ contractile ring. the cytoplasm divides into two cells. |
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Term
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Definition
| starts with cleavage furrow/ contractile ring. the cytoplasm divides into two cells. |
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Term
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Definition
| somatic cells-- what most cells in the body are. contain 46 chromosomes (a set form each parent). |
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Term
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Definition
| they contain only 1 set of genetic information, 23 chromosomes. gametes/sex cells/germ cells. |
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Term
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Definition
| merges the egg and sperm cell from parents, creating a zygote |
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Term
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Definition
| reduces the number of chromosomes in half, 46 to 23. |
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Term
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Definition
| produces 4 haploid nuclei from the 2 formed in meiosis 1. |
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Term
| prophase 1 (early) of meiosis |
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Definition
| replicated chromosomes condense, homologous chromosomes line up next to one another, become visible |
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Term
| prophase 1 (late) of meiosis |
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Definition
| crossing over occurs (exchange of genetic material between chromosomes), spindle forms, nuclear envelope breaks up. |
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Term
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Definition
| paired homologous chromosomes align along cell's equator |
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Term
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Definition
| homologous chromosomes separate to opposite poles of cell, sister chromatids remain joined. |
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Term
| telophase 1 & cytokinesis of meiosis |
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Definition
| nuclear envelopes form around chromosomes which temporarily condense, spindle disappears, cell divides in two |
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Term
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Definition
| spindles form, nuclear envelope breaks up |
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Term
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Definition
| chromosomes align along equator of cell |
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Term
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Definition
| centromeres split as sister chromatids separate to opposite poles of cell |
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Term
| telophase 2 and cytokinesis of meiosis |
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Definition
| nuclear envelopes assemble around daughter nuclei. chromosomes decondense. spindles disappear. cytokinesis divides cell. results in 4 nonidentical haploid daughter cells. |
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Term
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Definition
| portions of homologous chromosomes swap places. the resulting chromatids have allele combinations not found in either parent. |
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Term
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Definition
| an error in meiosis-- a gamete with one or more complete sets of extra chromosomes |
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Term
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Definition
| when chromosomes fail to separate at either the first or second meiotic division. One less chromosome = termination of fetus. one more = down's syndrome |
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Term
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Definition
| portion of DNA whose sequence of nucleotides (A,G,C,T) encodes a protein |
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Term
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Definition
| in plants, always produce offspring identical to themselves |
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Term
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Definition
| exerts its effects whenever present |
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Term
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Definition
| one whose effect is masked if dominant allele is present |
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Term
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Definition
| expresses the genetic make-up of an individual and it is written as a pair of letters representing the alleles |
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Term
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Definition
| a particular gene has 2 identical alleles, 1 contributed form each parent. ie) YY or yy |
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Term
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Definition
| 2 different alleles in a gene. ie) Yy |
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Term
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Definition
| observable expression of an allele combination |
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Term
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Definition
| a phenotype or allele resulting form a change in a gene |
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