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49 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Yolk sac |
Enables nutrient uptake Dev of circulatory system |
2 |
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Amnion |
Developed early Allows embryo to float in fluid environment |
2 |
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Allantois |
At posterior of embryo Stores waste |
2 |
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Chorion |
Where blood vessels exchange gases with environment |
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Placenta |
With holoblastic cleavage Enables internal development Tissues/blood from mom to developing |
2&1 |
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Blastodisc |
2-3mm diameter First cleavage is central |
2 |
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Blastoderm |
Single layer Develops to 5-6 cell thick with tight junctions |
2 |
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Subgerminal cavity |
Between blastoderm and yolk From absorbing water from albumin |
2 |
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Area pellucida |
Formed by deep central cells dying 1 cell thick Area forming most of embryo |
2&1 |
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Area opaca |
Peripheral ring of blastoderm retaining deep cells |
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Marginal zone |
Between area pellucida and opaca Determines early cell fate |
2 |
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Epiblast |
Area pellucida on surface of egg Form an upper layer |
2 |
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Kollers sickle |
After laid Local thickening of epiblast At posterior edge of area opaca |
1&2 |
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Posterior marginal zone |
Between area opaca and kollers sickle Initiates gastrulation Prevents margins from creating more primitive streaks |
1&2 |
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Primary hypoblast |
Anterior of hypoblast Delaminate 5-20 cells migrate to become |
3 |
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Secondary hypoblast |
Endoblast Sheet of anterior kollers sickle cells + primary hypoblast Joined at marginal zone Space between is blastocoel Contributes no cells to embryo Forms extraembryonic membranes Specifies migration of epiblast cells |
1&3&3 |
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Primitive streak |
Location of gastrulation Arises from kollers sickle and epiblast above it Defines major body axes Extends ap, separates lr, cells enter d to v |
2&2 |
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Primitive groove |
Depression within primitive streak Homologous to blastopore |
2 |
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Hensen's node |
Regional thickening at anterior of primitive streak Anterior portion of kollers sickle Become prechordal plate and chordamesoderm Can induce a secondary axis when transplanted |
2&2 |
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Primitive pit |
Funnel shaped depression central in hensens node Cells enter to form notochord and prechordal plate |
2 |
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Anterior of primitive streak |
Prechordal mesoderm Notochord Medial somites Endoderm Foregut |
3&2 |
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Lateral plate |
Cells ingressing through streak middle |
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Posterior of primitive streak |
Lateral plate Extraembryonic mesoderm |
2 |
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Neural plate formation |
Epiblast near primitive streak |
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Epidermis formation |
Epiblast cells far from primitive streak |
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Convergent extension |
Primitive streak extends anterior Anterior cells migrate ventrally Double length reduces width by 2 Directed by hypoblast |
2&2 |
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Germinal crescent |
Hypoblast cells confined to ant potion of area pellucida Precursors of germ cells |
2 |
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Migration through primitive streak |
Deep: displaces hypoblast to sides moving along midline form endodermal organs and most of extraembryonic membranes 2nd: forms loose layer of cells between endoderm and epiblast mesodemal Longer inside streak determines which hox genes are expressed |
2&1 |
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Fgf8 |
In primitive streak Repels cells away from streak |
2 |
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Wnt5a |
Posterior Directs cells create lateral plate mesoderm Inhibited in anterior by wnt3a |
2&1 |
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Wnt3a |
Directs cells to firm paraxial mesoderm |
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Chick filopodia |
Cytoplasmic processes attach to vitelline envelope |
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Gravity |
Changes radial symmetry to bilateral Rotated as passed through repro tract 20hr @ 15rev/hr Imbalance- one end tips up and becomes posterior Upper becomes pmz and primitive streak |
1&2&2 |
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Chick organizer |
Anterior to pmz |
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Dorsal mesoderm |
Induces formation of CNS in overlying ectoderm |
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Roles of fgf in gastrulation |
From hypoblast Specifies mesoderm Separate mesoderm formation from neurulation (ingression) Induce activation of Churchill Neurulation in central ectodermal cells Induce erni and sox3 (preneural genes) |
1&2&3 |
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Ap pattern |
Different in meso and neural ectoderm Time regulated Initial neural plate is future head region |
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Caudal lateral epiblast |
Nervous system Posterior hindbrain Spinal cord |
3 |
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Hox genes |
Homologue drosophila homeotic genes Expressed more in posterior |
2 |
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Left side specification |
Nodal and pitx2 Shh gene |
2 |
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Shh |
Blocked by activin and bmp4 Activates fgf8 Activates Cerberus on left side |
3 |
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Fgf8 |
Blocks cerberus on right side |
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Cerberus |
With BMP stimulates nodal Prevented from diffusing right by lefty1 |
2 |
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Nodal |
Activates pitx2 Represses snail |
2 |
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Ampulla |
Part of oviduct Location of fertilization Sperm entry starts meiosis |
2&1 |
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Mammal cleavage |
1st depends on sperm entry location via microRNA Slowest in animal kingdom Starts while moving to uterus Rotational Asynchronous, not exponential Zygotic proteins activated early in cleavages |
1&2&2&1 |
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Sperm microRNA |
Inhibits bcl2 Prevents s phase |
2 |
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Mzt |
Parental receives new histones Gamete-specific DNA methyl groups removed 16 hypomethylated cells all pluripotent |
3 |
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Compaction |
Most crucial event in cleavage After 3rd cleavage Expression of e cadherin and tight junctions |
2&1 |
