An enzyme is a protein that ________.
A. has only primary structure
B. can catalyze many different reactions
C. changes the rate of a metabolic reaction without being consumed by the reaction
D. provides activation energy for the reactions it facilitates
C. changes the rate of a metabolic reaction without being consumed by the reaction
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The spatial arrangement of different regions in the body is called a _______
A. pattern B. morphogen C. induction D. segment
As described in "A Note About Bacterial Reproduction -- and the "Culture Bias,"" the organism Epulopiscium does not divide by binary fission. Rather, each cell increases in size and divides to produce multiple daughter cells that are held within the original cell well. After lysis, those daughters are released to repeat the process. Assuming Epulopiscium could be grown in pure culture in the laboratory in broth and on solid media (it currently cannot), which method would be best for measuring the increase in biomass during growth?
A. Direct microscopic count; the experimenter can directly count the number of cells and extrapolate to the biomass. B. Turbidity readings from a spectrophotometer; the increase in biomass will directly vary with the turbidity of the culture. C. Chemostat growth; it will prevent the culture from entering the death phase. D. The viable plate count; each colony derives from a single cell and the number of colonies equals the number of cells.
Which of the following poses the best evidence that cell-signaling pathways evolved early in the history of life?
A) Cell-signaling pathways are seen in "primitive" cells such as bacteria and yeast. B) Bacteria and yeast cells signal each other in a process called quorum sensing. C) Signal transduction molecules identified in distantly related organisms are similar. D) Most signals in all types of cells are received by cell surface receptors.
Injury localized to the hypothalamus would most likely disrupt _____
A) short-term memory B) coordination during locomotion C) executive functions, such as decision making D) regulation of body temperature