Describe a hypothetical situation in which two isolated human populations evolve very different muscle fiber composition. In other words, what environmental conditions or food-gathering strategies might cause a prevalence of one fiber type (fast-twitch versus slow-twitch) to be more adaptive than another?
What will be an ideal response?
One might suggest that slow-twitch fibers are adaptive for hunters that used distance running to chase down prey that were fast but easily winded. In contrast, if prey animals were relatively slow moving, human hunters with lots of fast-twitch fibers might eat well and pass on their genes.
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Large birds can break or amputate fingers with their beaks
Indicate whether the statement is true or false
The mitochondrion is the site of ________.
A. glycolysis B. lactate formation C. the citric acid cycle D. electron-transport chain E. Both "the citric acid cycle" and "the electron-transport chain" are correct.
A cofactor is ________. Examples are ________.
A. a necessary part of some enzymes; copper, iron, and zinc B. a molecule that destabilizes substrates; carbonic acid C. an inorganic molecule that some enzymes require; vitamin B12 and B6 D. an inorganic molecule that all enzymes require; cholesterol and calcium
Which statement is true regarding the anatomy of the nerves in the parasympathetic nervous system?
A. Preganglionic neurons come off the lumbar and sacral region of the spinal cord, and synapse with post ganglionic neurons in ganglia close to the structure they stimulate. B. Post ganglionic neurons come off the brain and the sacral region of the spinal cord, and synapse with preganglionic neurons in ganglia close to the structure they stimulate. C. Preganglionic neurons come off the brain and the sacral region of the spinal cord, and synapse with post ganglionic neurons in ganglia far from to the structure they stimulate. D. Preganglionic neurons come off the brain and the sacral region of the spinal cord, and synapse with post ganglionic neurons in ganglia close to the structure they stimulate.