To Identify the Variables Influencing Vascular Resistance, a Researcher Is

question 168

Multiple Choice

To identify the variables influencing vascular resistance, a researcher is performing an experiment. Animals used in experiments are sedated, intubated, and connected to a ventilator under control. Each animal has a catheter inserted into a tiny artery in a different organ. The catheter is attached to an oximeter and a manometer, which both record oxygen saturation and pressure over time. At regular intervals, arteriolar resistance is determined from the manometer data and the fraction of inspired oxygen is gradually altered. The results shown below were most likely obtained from which of the following organs?

• A)Brain
• B)Heart
• C)Kidneys
• D)Lungs
• E)Small intestine

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Definitions:

Negative Control

An experiment or part of an experiment where no response is expected, serving to highlight the effect of the experimental treatment.

Repressible Genes

Genes whose expression can be decreased or turned off by the presence of a specific molecule.

Transcription

The process by which genetic information encoded in DNA is copied into messenger RNA (mRNA) for protein synthesis.

Inducible Operon

A genetic regulatory system found in bacteria that can be activated or repressed in response to specific environmental conditions, allowing adaptation to the environment by controlling gene expression.