Infection by rubella virus: In adults, rubella (German measles) is a relatively mild disease, but if the virus passes from an infected mother to her embryo, it may have severe consequences.Children born with this disorder may have cognitive deficits, developmental delays, behavioral issues, and distinctive facial features. Alcohol consumption: Exposure of the embryo to alcohol from the mother’s blood can cause fetal alcohol spectrum disorder.If the embryo survives and goes on to develop and grow as a fetus, it is likely to have birth defects.Įnvironmental exposures are known to have adverse effects on the embryo include: and neuronal complexity of bipinnaria larvae of the sea star Asterias rubens. They may cause the embryo to die and be spontaneously aborted (also called a miscarriage). Labels are: aar, anterior apical region be, blastopore cb, ciliary band. Genetic defects or harmful environmental exposures during this stage are likely to have devastating effects on the developing organism. In reptiles (nonavian reptiles, in the context of this article), gastrulation is associated with involution (i.e. Events that occur in the embryo lay the foundation for virtually all of the body’s different cells, tissues, organs, and organ systems. The embryonic stage is a critical period of development. Genetic and Environmental Risks to Embryonic Development The neural tube also develops a bulge at one end, which will later become the brain. Most of the neural tube will eventually become the spinal cord. 19, Some asteroids feed heavily on molluscs but Asterias is never a. The convergence of the neural plate borders also results in the formation of a neural tube. B), Their anus develops from or near the blastopore whereas the mouth develops from. The neural plate then starts to fold inward until its borders converge. It begins when a structure of differentiated cells called a neural plate forms from the ectoderm.
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