In birds and mammals, a vestige of the sinus venosus of the fish heart remains as the sinoatrial node, which serves as a(n)
A. pacemaker.
B. inhibitory node.
C. diastole detector.
D. site of erythropoiesis.
E. baroreceptor.
A. pacemaker.
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The constituents of the electron transport chain have similar capabilities, with the exception of ubiquinone (coenzyme Q). What is different about ubiquinone?
A) Ubiquinone is a protein that begins the electron transport chain, so it accepts the highest-energy electrons. B) Ubiquinone is a protein that serves as a regulator of the rate of redox reactions in the electron transport chain. C) Ubiquinone is a protein that is a constituent of all cells, prokaryotic or eukaryotic; hence its name, originating from "ubiquitous." D) Ubiquinone is not a protein, is lipid soluble, and can move through the inner mitochondrial membrane.
Eukarya" is a _________.
Fill in the blank(s) with the appropriate word(s).
What phenomenon results from the runoff of fertilizers from agricultural and residential areas causing the aquatic algae in bodies of water to grow prolifically?
A) competitive exclusion B) habitat fragmentation C) eutrophication D) overexploitation
Complete the equation: monosaccharide + monosaccharide ? ________ + water
A) disaccharide B) polypeptide C) polysaccharide D) fat