The Work of Meselson and Stahl

question 40

Multiple Choice

The work of Meselson and Stahl:

• A) Showed that DNA replication semiconservative, which means that the parental double helix is conserved.
• B) Used the radioisotope ³H-thymidine in conjunction with centrifugation to separate DNA on the basis of size
• C) Showed that the DNA, after one round of replication, was of intermediate density thereby showing that the DNA molecules contained one parent strand and one new strand.
• D) All of these
• E) None of these

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Definitions:

Tolman

A cognitive psychologist known for his work on latent learning and cognitive maps in rats, challenging behaviorist theories.

Pheromones

Chemical substances released by animals (including humans) that affect the behavior or physiology of others of the same species, often involved in attraction.

Chemical Signals

Molecules released by organisms that influence the behavior or physiology of others, fundamental in processes such as communication and mating.

Mourning

The process of expressing grief and sorrow for someone who has died, often involving rituals and practices specific to a culture or individual.