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1. Which of the following is correct about the role of regulatory elements in eukaryotic transcription?

9. Which structure on tRNA recognizes and binds to the complementary bases on mRNA?

Multiple Choice Questions. Write the letter of the single best answer for each number on your paper. Fifteen items, each one is worth 3 points. (45 points total)

Which of the following requirements for biopotential amplifiers is most directly addressed by using an instrumentation amplifier with a high common-mode rejection ratio (CMRR)?   Should not influence the physiological process being monitored Should not distort the measured signal Should provide the best possible separation of signal and interferences Should offer protection from electrical shock

Which type of overpotential results directly from the resistance of the electrolyte solution between two electrodes?   Concentration overpotential Activation overpotential Ohmic overpotential Polarization overpotential

What if the high-pass filter in an EMG measuring device failed and stopped functioning, essentially becoming a wire? If this happens during an EMG recording session on the patient’s bicep and the patient frequently moves his arm, disturbing the electrode-skin contact, what would most likely appear in the output signal?   Complete loss of the EMG signal Large, slow-varying baseline wander and DC offset that could saturate the subsequent amplifier stages Increased 60 Hz power line interference Loss of the high-frequency components of the EMG signal

Consider the ideal op amp  Which of the following is TRUE?   The value of v0 is always linear with (vp – vn) The possible values of v0  are affected by VCC The impedance at the inverting terminal is negligible The output impedance is infinite

What is the primary function of a biopotential electrode when recording signals such as ECG or EEG from the body?   To amplify the biopotential signal before it reaches the measuring device To convert ionic current in the body into an electronic current that can be measured by instruments To generate electrical signals that stimulate nerve and muscle tissue To filter out noise and artifacts from the recorded signal

A student reads that only 1/100,000 of the total K⁺ ions in a cell need to flow out to change the membrane potential by 100 mV. The student wonders why the concentration gradient doesn’t change significantly despite this ion movement. What explains this phenomenon?   The Na⁺– K⁺ pump immediately replaces every K⁺ ion that leaves, maintaining a constant concentration  Only a thin surface layer of ions (< 1 nm) near the membrane creates the potential, representing a tiny fraction of total cellular K⁺, so bulk concentration remains essentially unchanged  K⁺ ions that leave are immediately replaced by Cl⁻ ions to maintain electrical neutrality The cytoplasm has buffering proteins that prevent concentration changes

While on a medical volunteer trip to an impoverished country, you encounter a patient whose eyelids are turned inward as shown. What is the cause and the best treatment?