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Results for: 'rna'
By: Administrator, Views: 10783
The ear is the organ of hearing and, in mammals, balance. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most ani...
By: Administrator, Views: 11918
The brain’s cerebral cortex is the outermost layer that gives the brain its characteristic wrinkly appearance. The cerebral cortex is divided lengthways into two cerebral hemispheres connected by the corpus callosum. Traditionally, each of the hemispheres has been divided into four lobes: front...
Dissociative Disorders (Part 1)
By: Administrator, Views: 10740
Dissociative disorders (DD) are conditions that involve disruptions or breakdowns of memory, awareness, identity, or perception. People with dissociative disorders use dissociation as a defense mechanism, pathologically and involuntarily. Some dissociative disorders are triggered by psychological...
By: Administrator, Views: 429
At conception, the gender and other biologic traits of the new individual are determined. The zygote is genetically complete and immediately begins to divide, forming a solid mass of cells called a morula. When the developing embryo (stage of development between weeks 2 and 8) reaches the ute...
By: Administrator, Views: 11016
Eye Composed of special anatomical structures that work together to facilitate sight: Cornea Pupil Lens Vitreous body Light stimulates sensory receptors (rods and cones) in the retina or innermost layer of the eye. Vision is made possible through the coordinated actions of nerves that co...
By: Administrator, Views: 11851
The lac operon (lactose operon) is an operon required for the transport and metabolism of lactose in Escherichia coli and many other enteric bacteria. Although glucose is the preferred carbon source for most bacteria, the lac operon allows for the effective digestion of lactose when glucose is no...
Embryonic development - Weeks 5 to 8
By: HWC, Views: 7884
• The second month of development is characterized by rapid development of the head and limbs as well as continued organogenesis. • During the fifth and sixth weeks growth of the brain, and therefore head, is rapid. • Hands and feets begin to form. • During week seven, even more deve...
Embryonic development - Week 3
By: HWC, Views: 7815
Week 3 (gastrulation) • Three primary germ layers are formed which provide cells for organ formation in the following months. • These germ cell layers are formed by a process known as gastrulation, which involves rearranging epiblast cells. • As cells from the epiblast migrate, a fain...
Embryonic development - week 1 and 2
By: HWC, Views: 7746
The first through eighth weeks after fertilization are called the embryonic. Week 1 • Within a day, the zygote begins mitotic cell division (cleavage) forming blastomeres. By the 4th day, the blastomeres have formed a solid ball called a morula. • The morula enters uterine cavity ar...
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