Term
| What does fertilization activate in sexually reproducing organisms? |
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Definition
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Term
| what happens as soon as fertilization takes place? |
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Definition
| a rapid series of cell divisions initiates to become a multicellular embryo |
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Term
| The embryo gets nearly everything it needs from where? |
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Definition
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Term
| the sperm contributes a centriole to the egg, which becomes what? |
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Definition
| the centrosome of the zygote (it organizes mitotic spindles) |
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Term
| the egg sets up signaling cascades that orchestrate what? |
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Definition
| the major events of development |
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Term
| what are the major events of development? |
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Definition
- determination - fate is set
- differentiation - similar cells, different development
- morphogenesis - development of form |
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Term
| Which part of the egg is the vegetal hemisphere? |
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Definition
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Term
| which part of the egg is the animal hemisphere, where the nucleus is located? |
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Definition
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Term
| the egg is radially symmetric along which axis? |
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Definition
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Term
| when the sperm enters the egg, an anterior-posterior axis is created and the cytoplasm rotates to from what? |
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Definition
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Term
| what plays a major role in cell-cell signaling process of determination & differentiation? |
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Definition
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Term
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Definition
| rapid series of cell division of zygote with DNA replication & mitosis, but little cell growth & gene expression |
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Term
| what happens early on because the cytoplasm of the zygote is not homogenous? |
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Definition
| the first cell divisions result in the differential distribution of nutrients & cytoplasmic determinants in the early embryo. |
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Term
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Definition
| a blastocoel is a fluid filled cavity in a ball of cells called blastomeres, which is collectively called the blastula |
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Term
| what is complete cleavage? |
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Definition
| the complete division of the egg |
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Term
| species with little yolk often have what type of cleavage? |
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Definition
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Term
| Spiral cleavage results from what? |
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Definition
| oblique angles to the animal-vegetal axis |
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Term
| what is incomplete cleavage (discoidal cleavage)? |
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Definition
| partial division of the top of the egg |
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Term
| incomplete cleave is characteristic of species with what type of yolk? |
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Definition
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Term
| what is superficial cleavage? |
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Definition
| mitosis without cell division; one cell with lots of nuclei |
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Term
| In superficial cleave, the nuclei migrate to where? |
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Definition
| the periphery & membrane infolds |
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Term
| Mammalian cleavage is much slower and takes how many hours between divisions? |
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Definition
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Term
| T/F there is synchronicity in mammalian cleavage. |
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Definition
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Term
| at what stage in mammalian cleavage do the products of gene expression play a role? |
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Definition
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Term
| Mammalian eggs maximize surface area contact, forming tight junctions and becomes what? |
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Definition
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Term
| From the 16-32 cell stage the cells separate into what? |
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Definition
| the inner cell mass & the trophoblast |
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Term
| In the 16-32 cell stage, the trophoblast secrete a fluid resulting in a blastocoel with the inner mass cell on the other end of the embryo, at this point the embryo is called what? |
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Definition
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Term
| why are there major differences in the mammalian embryo? |
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Definition
| because there is a lack of yolk |
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Term
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Definition
| the attachment of the blastocyst (fertilized egg) into the endometrium (lining of the uterus). |
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Term
| The mammalian blastocyst must form what 2 structures? |
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Definition
| the embryo & the support structure (the placenta) |
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Term
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Definition
| a diagram or series of diagrams indicating the later structures or adult parts that develop from specific regions of an embryo or egg cortex. |
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Term
| what does it mean when a blastomere becomes determined? |
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Definition
| it is committed to a specific fate |
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Term
| what is mosaic development? |
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Definition
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Term
| what is mosaic development? |
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Definition
| the blastomeres are restricted because they contribute to a particular portion, removal of one of these will result in a deformed organism |
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Term
| what is regulative development? |
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Definition
| other blastomeres can compensate for removed ones |
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Term
| What are embryonic stem cells? |
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Definition
| pluripotent cells of mammalian blastocysts |
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Term
| identical twins, non-identical twins, & conjoined twins can be a result of mosaic development or regulative development? |
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Definition
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Term
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Definition
| the massive movements of cells to create an embryo with multiple tissue layers |
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Term
| the digestive tract, respiratory tract, pancreas & liver are characteristic of which tissue layer? |
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Definition
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Term
| the mesoderm contains what? |
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Definition
| the heart, blood vessels, & bones |
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Term
| the ectoderm is comprised of what? |
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Definition
| the nervous system, eyes, ears, skin & teeth |
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Term
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Definition
| the simultaneous & coordinated development of individual organs from various tissue layers |
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Term
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Definition
| the formation of the internal neural tube from an external sheet of cells |
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Term
| the notochord results from which tissue? |
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Definition
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Term
| what is the function of the notochord? |
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Definition
| it provides structural support |
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Term
| the notochord is eventually replaced by what? |
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Definition
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Term
| what happens in neurulation? |
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Definition
- the ectoderm overlaying the notochord is thickened
- the invagination of this layer leads to a tube, but the outermost portions are not part of this tube
- neural crest cells are responsible for developing connects of the CNS and the rest of the body
- the anterior bulge becomes the brain & the rest becomes the spinal chord |
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Term
| when does segmentation develop? |
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Definition
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Term
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Definition
| segmented blocks of cells formed by mesodermal tissues gathering along side the notochord |
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Term
| neural crest cells migrate between segments & often become what? |
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Definition
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Term
| Differentiation along the anterior-posterior body axis are controlled by which genes? |
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Definition
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Term
| The protein called Sonic hedgehog results in the development of what? |
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Definition
| motor neurons from the neural tube |
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Term
| following segmentation, organogeneis is slow or rapid? |
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Definition
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Term
| What is the first extraembryonic membrane to form which provides nutrition to the embryo? |
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Definition
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Term
| the allantois functions to do what? |
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Definition
| store waste & exchange gas |
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Term
| what is the purpose of the amnion? |
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Definition
| it surrounds the embryo (amniotic cavity) and secretes fluids |
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Term
| what is the chorion & what does it do? |
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Definition
| the chorion is the continuous membrane under shell, it limits water loss & helps gas exchange |
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Term
| which enzymes help the trophoblast burrow into the endometrium? |
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Definition
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Term
| eventually the entire trophoblast is within where? |
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Definition
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Term
| the mesodermal tissues will interact with the trophoblast tissues to form what extraembryonic membrane? |
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Definition
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Term
| what makes up the placenta? |
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Definition
| the chorion along with the tissues of the uterine wall |
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Term
| The placenta functions to do what? |
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Definition
| exchange nutrients, gasses, & waste from the embryo to the mother |
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Term
| T/F the amnion is a fluid filled cavity |
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Definition
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Term
| the allantois is minor in humans but contribute to the formation of what? |
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Definition
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Term
| Gestation "pregnancy" is what? |
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Definition
| the development of mammalian embryo in placenta |
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Term
| how long is the gestation of mice? |
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Definition
|
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Term
| how long is the gestation for humans? |
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Definition
|
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Term
| how long is the gestation for horses |
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Definition
|
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Term
| how long is the gestation for elephants? |
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Definition
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Term
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Definition
| the three, three-month periods of human development |
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Term
| implantation into the endometrium happens on what day in humans? |
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Definition
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Term
| in humans, a heartbeat is present when? |
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Definition
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Term
| limb formation occurs when? |
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Definition
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Term
| a developing human is called a fetus at what point? |
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Definition
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Term
| What are characteristic of the 2nd trimester? |
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Definition
| fingers, toes, facial features, eyebrows, fingernails, limb elongation, & movement |
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Term
| what is characteristic of the 3rd trimester? |
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Definition
| organ maturation, digestive system function, glycogen storage, urine production, & sleep wake cycles |
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Term
| birth is set on by the maturation of what organ? |
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Definition
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