In a Sequence of DNA Taken from Various Species of Snails

question 88

Multiple Choice

In a sequence of DNA taken from various species of snails, researchers have found that the rates of nonsynonymous substitutions and synonymous substitutions are roughly the same. What can we infer from this pattern?

• A) Transversions are more common than transitions.
• B) Most of the amino-acid changes are neutral.
• C) Strong stabilizing selection is acting on this gene.
• D) Strong selection for change is acting on this gene.
• E) None of the above

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Definitions:

Cardiopulmonary Resuscitation

An emergency procedure combining chest compressions with artificial ventilation to manually preserve intact brain function in a person who is in cardiac arrest.

Chest Compressions

A life-saving technique that involves pressing on the chest of someone who has had a cardiac arrest, to maintain blood circulation.

Code Situation

A term used in healthcare environments to indicate an emergency situation where immediate medical assistance is required, often specifying types like code blue for a cardiac arrest.

Pulse Checks

The act of palpating a pulse to determine heart rate and rhythm, typically performed at accessible arteries such as the wrist or neck.