Oxygen moves from alveoli to the bloodstream ____.
A. because the partial pressure of oxygen is greater in alveoli than in the blood
B. mainly due to the activity of carbonic anhydrase in the red blood cells
C. against a concentration gradient
D. to equal the concentration of CO2 in the blood
E. by active transport
Answer: A
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The facial nerve controls facial expression muscles and conveys taste from the tongue, which are _________ and _________ parts of the nervous system
A. somatic; voluntary B. somatic; involuntary C. autonomic; voluntary D. autonomic; involuntary
Which of the following is the main component of cell membranes?
A. phospholipids B. steroids C. cholesterol D. sucrose E. triglycerides
Humans become infected with Fasciola by
A) ingesting cysts on vegetation. B) consuming cysticerci in contaminated meat. C) ingesting water contaminated with eggs. D) the penetration of cercariae through the skin. E) the bite of infected mosquitoes.
How do dietary factors interact with DNA methyltransferase to affect an organism's phenotype in an epigenetic manner?
A. Some dietary factors upregulate DNA methyltransferase activity, increasing the overall methylation of the organism's DNA and changing its gene expression B. Some dietary factors degrade DNA methyltransferase, preventing it from removing methyl groups from sections of DNA, thereby altering gene expression C. Some dietary factors bind to DNA methyltransferase and enable it to methylate DNA, thereby changing gene expression D. Some dietary factors inhibit DNA methyltransferase activity, reducing the methylation of the organism's DNA and changing its gene expression E. Some dietary factors interact with methyl groups directly preventing DNA methyltransferase from methylating any DNA, changing gene expression in the organism as a result