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22 Cards in this Set
- Front
- Back
desriptive embryology? |
Describe what is happening inside and outside
developing fate maps, detailing the destiny of each cell
catalouging gene expression, when and where genes are being expressed
no or little interferrring with the process |
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experimental embryology? |
work out how and why everything is happening
experiments to find how development occurs
includes transplant studies to find whether cells or tissues obtain their fates from neighbours or determinants |
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what is the common labelling method |
blue= ectoderm ( outside of cell)
red= mesoderm (formed during gastrulation)
yellow = endoderm (inside of cell) |
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What are thought to be the methods that the fate of cells are determined? |
1) Inheritance of cell fate determinants
( Aysmmetrical inheritance of cytoplasmic determinants)
2) Cell-cell communication / induction |
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How did dropsphilia embryos indicate mosaic development? |
their egg cells are already assymetrical
studies showed how determinants in portions of the cytoplasm determine cell fate |
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how does one find out how much of a role cell-fate determinants play in dertmining how cells develop? |
compare a fate map to a specification map
fate maps are produced from following cells and their daughters fates etc
specification maps are developed by removing cells from the embryo, this isolates them from their environment,
what the isolated cells develop into provides a specification map |
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general differences between mosaic and regulatory devlopment |
mosaic development, if cell is removed, what that cells fate would have been is removed (cell determinants)
regulatory development, can adapt from being removed ( cell-cell communication) |
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how could you prove regulatory devlopment? |
cells that |
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stages of frog development? |
blastula
gastrula: gastrulation
neurula: neural tube forming
tailbud
tadpole/ prelarval |
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what are the cells of blastula called? |
blastopore |
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morphogenesis? |
process by which form is generated, involves coordinated cell movements |
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gastrulation? |
morphogentetic process in which the endoderm, mesoderm and ectoderm layers reach their final positions in the embryo |
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neuralation? |
morphogenetic process in which the nervous system begins to develop, formation of neural tube |
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fate map? |
assesement of fate of a cell or group of cells based on lineage labelling
part of distriptive embryology, as it does not involve interupting normal functioning, |
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specification map? |
assesment of what a cell or group of cells will form if removed from their embryonic environment |
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what is it where a cell is 'determined,'? |
a cell or tissue that is determined if, when it is removed or transplanted it will still develop accordingly
example dorsal lip of blastopore (organiser) will still determined to become a notochord even if it is transplanted to ventral side of embryo |
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what is it where cell speciation map is not same as fate map? |
indicates that some cells must have receive signals from neighbours (cell-to-cell) at a later stage of development that determine their fate |
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competence? |
competence is the range of cell fates, which can be achieved by a cell or a group of cells in a given set of conditions
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Induction? |
the process in which cell or group of cells emit signals to its neighbouring cells, thereby changing its fate
example is the induction of neural ectoderm by dorsal mesoderm in organizer exp |
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breifly state what happens in the organizer experiment? |
induction of muscle (somites) and neural tissue by the transplanted dorsal mesoderm
the dorsal mesoderm that was transplanted onto the ventral side of the embryo is already determined by early gastrula stage
the fact that the ventral ectoderm and mesoderm can develop into neural and muscle tissue means they are competent to become then |
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what is the organiser region of the gastrula? |
it is the dorsal mesoderm at the gastrula stage of the embryo
it induces overlying ectoderm to become neural
and neighbouring mesoderm to become muscle |
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what is the nieuwook centre? |
region of the early blastula stage which induces the organiser |