The Famous Meselson and Stahl Experiment Showed

question 4

Multiple Choice

The famous Meselson and Stahl experiment showed:

• A) DNA is replicated by a semi-conservative mechanism.
• B) The direction of DNA synthesis proceeds 5' → 3'.
• C) The isotope ¹⁵N is denser than ¹⁴N.
• D) DNA replication is semi-conservative and ¹⁵N is denser than ¹⁴N.
• E) All of these are correct.

---

Definitions:

Hamilton's Rule

A principle stating that an act of altruism is favored by natural selection if the genetic gain of the recipient, discounted by the relatedness between the altruist and the recipient, exceeds the cost to the altruist.

Adaptive

Traits or behaviors that enhance an organism's ability to survive and reproduce in its environment.

Multilevel Selection

A concept in evolutionary biology that argues selection operates not just on individuals, but also on groups, genes, or traits at different biological hierarchy levels.

Eusociality

The highest level of social organization in animals, characterized by cooperative brood care, generational overlap, and a division of labor between reproductive and non-reproductive individuals.