This figure illustrates 3 hypotheses of how a cancer stem cell may arise: (1) A stem cell undergoes a mutation, (2) A progenitor cell undergoes two or more mutations, or (3) A fully differentiated cell undergoes several mutations that drive it back to a stem-like state.
The statement that best describes ecological succession is that it always occurs in a predictable pattern. The process is also slow. The correct answer is C.
Answer AND Explanation:
As light reflected from an external object enters the eye, it is refracted by the cornea, aqueous humour, the lens and vitreous humour so that an image is focused on the retina. The image is real, upside down and smaller than the object. The photoreceptor cells are stimulated by the reflected light and impulses are set off. The impulses are transmitted by neurons through the optic nerve to the optic region of the brain. The brain interprets the impulse as an upright impression of the object.
Answer:
Cervical and Thoracic areas.
Explanation:
The most common sites of injury are the cervical and thoracic areas. SCI is a common cause of permanent disability and death in children and adults. The spine has 33 vertebrae.
