You Decide to Repeat the Meselson-Stahl Experiment,except This Time You

question 68

Multiple Choice

You decide to repeat the Meselson-Stahl experiment,except this time you plan to grow the E.coli cells on light ¹⁴N medium for many generations and then transfer them to heavy ¹⁵N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication) .If the conservative model of DNA replication was correct,what is the expected distribution of DNA in the density gradient after two rounds of replication?

• A)One band of intermediate density.
• B)One band of light density.
• C)One band of heavy density.
• D)One band of light density and one band of heavy density.
• E)One band of light density and one band of intermediate density.

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Definitions:

Parallel Processing

The ability of the brain to simultaneously process incoming stimuli of differing quality, a cornerstone of nearly all cognitive functions.

Dual-Processing System

The concept in psychology that suggests there are two different systems in the brain for processing information: one that is fast, automatic, and nonconscious, and another that is slower, more deliberate, and conscious.

Circadian Rhythm

The natural, internal process that regulates the sleep-wake cycle and repeats on each rotation of the Earth roughly every 24 hours.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.