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important traits to distinguish protostomes |
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Definition
dorsal brain connected to a ventral nerve cord |
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nephrozoa - they all have exretory system. [kidneys or something like it] |
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2 categories of protostomes |
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bryozoans and brachiopods - tentacle like structures around their mouths to guide in plankton |
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Definition
shedding exoskeleton [molting or ecsysis] |
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Definition
insects,spiders, and crustaceans |
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limitations on ecdysozoan growth |
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Definition
-exoskeleton made of chitin or secondarily laid down in calcium carbonate -Limbs are armored and so muscles have to attach between those joints and on internal surfaces |
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Term
Constraints during ecdysozoan growth |
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Definition
-Growth can’t be continuous -must occur through numerous cycles of deposition of the exoskeleton followed by molting or disassembly of it |
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ecdysozoan between molts while it is in larval stage; resembles the one before it |
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complete and incomplete metamorphosis |
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Definition
insect development in which egg, larval, pupal, and adult stages occur, each differing greatly in morphology |
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pupal stage in ecdysozoan |
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Definition
after last larval instar, stays inactive to avoid harsh weather, hardens quickly, and all pigmentation occurs rapidly |
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Definition
region of egg where sperm enters |
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Definition
a single diploid cell that has just undergone nuclear fusion – the nucleus of the sperm fuses with genetic material of egg to form genetic nucleus of ________ |
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Definition
results from early cell division; hollow cavity inside called ______ |
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Definition
results from early cell division; hollow cavity inside called ______ |
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Definition
animal pole; vegetal pole |
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Definition
continuous growth of cells in various regions of ______ are becoming differentiated into endoderm, mesoderm and ectoderm |
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Definition
[primitive gut] becomes endoderm in gastrula |
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Term
movements due to cytoskeleton |
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Definition
The actin fiber of the cell can move expand or contract and they create furrow that grows deep enough for the two cells to form on either side. Eventually 2 daughter cells will form due to __________ |
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Definition
separate cytoplasm into 2 separate compartments [each with its own cytoplasmic content] |
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have complete cleavage where a plane of separation cuts completely through the dividing cell and all subsequent mitosis is the same. |
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distribution of yolk in zygote |
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Definition
more yolk is found in vegetal pole then animal pole and results in different cell size [small at animal pole]. |
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Definition
lots of yolk at vegetal pole,so it isn't cut in two -- results in mitotic activity on top so embryonic activity happens above the yolk |
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Term
superficial cleavage[peculiar to protostomes] |
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Definition
cytopasmic contents are distributed evenly and mitosis occurs, numerous nuclei are produced but no plane of separation - happens at the early stage |
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Definition
fungi; single cell with multiple nuclei [nuclear divisions but no cell division until later] - forms a yolk pore and a single layer of embryonic cells b/c the nuclei migrate to the periphery |
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lots of nuclear divisions without any mitosis and sometimes it can lag behind the rapid rate of nuclear division - and maybe you can get only a few nuclei per mitotic round |
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Definition
every time you get a nuclear division, you also get a cellular division, and each resulting daughter cell ends up with one nucleus |
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Definition
early daughter cells of original zygote |
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Term
purpose of hollow hole in blastocele |
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Definition
ensures seperation between activities that are occurring up and down poles and this is one of the keys to differentiation in the embryo |
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Definition
developmental ability to produce viable organisms |
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Term
3 stages of cell differentiation |
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Definition
totipotent, pluripotent, committed cell lineages |
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Term
example of pluripotent cell |
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Definition
bone marrow - give rise to numerous different types of blood -- cannot go back and form other tissues |
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Definition
certiain cytoplasmic determinants exist in the egg -- equally distributed = totipotency; uneven = committed to different fates |
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Definition
proteins that bind to DNA and control what genes get turned on during transcription [gene expression] |
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