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21 Cards in this Set
- Front
- Back
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what is the main difference between somatic and germ-line cells
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germ-line cells are passed to offspring while somatic cells form the body of the organism
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what is potency
-what are zygotes considered |
describes range of different cell types that a cell could become
-totipotent because they can become complete organisms |
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define determination and differentiation
-what does differentiation result from |
determination - cell "chooses" its fate
differentiation - cell type develops clear-cut identities -differential gene expression |
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what is significant about C. elegans
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-gonads consist of 2 mirror image arms
-same number of somatic cells (959 for hermaphrodites) |
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what are PAR genes
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they partition genetic material in cells into the anterior and posterior part of the cell
-occurs when sperm enters the cell |
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what are P-granules
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maternally-derived structures (RNA, proteins) that are located in posterior part of the cell due to PAR genes. They are always passed on to the offspring
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In C. elegans, what is the primordial germ-line cell
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P4
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how many phases does Drosophila development have
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5
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what is the overall order of gene expression in drosophila development
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maternal genes expressed
transcription zygotic genes expressed |
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in drosophila development, what is significant about the maternal genes
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mRNA, proteins
-distributed in a gradient, or concentrated in specific regions of the embryo cell -encode for transcription factors that affect zygotic gene transcription |
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what are the 3 zygotic genes in drosophila development
-where are they transcribed |
gap genes, pair-rule genes, segment polarity genes
-transcribed in nucleus of the embryo |
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purpose of gap genes
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divide embryo into broad sections (head, thorax, abdomen)
-transcription factor proteins that control expression of pair-rule genes |
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purpose of pair-rule genes
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divide embryo into 7 narrow bands along the circumference
-transcription factors control segment-polarity gene expression |
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purpose of segment-polarity genes
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become active in the narrow bands, divide embryo into 14 segements (anterior, posterior axes)
-Hox genes give these segments their identity |
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what are homeotic genes
-called in drosophila |
determine adult structures from each segment
-Hox genes |
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what are homeotic mutants
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two segments form identical structures (antenna forms leg)
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what are the 2 Hox genes in drosophila
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-Antennapedia complex: head, first 2 thoracic segments
-Bithorax complex: second thoracic, entire 3rd thoracic, abdomen |
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how are Hox genes expressed
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collinearly
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what are purpose of Hox genes in vertebrates
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play fundamental role in shaping the body and appendages
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what are signaling systems in the body
-what is their purpose |
cell-cell interactions that act independently or in a coordinated network
-influence/communicate about developmental fate of neighbors (make sure neighboring cells do not become same structure) |
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what is purpose notch-signalling pathway
-2 parts of it |
specifies the fate of equivalent, neighboring cells
-Notch-gene: receptor -Delta-gene: signal |
