Which of the Following Is NOT One of the Key

question 36

Multiple Choice

Which of the following is NOT one of the key reasons that so many spacecraft from Earth have visited Venus and Mars?

• A) they are the two planets closest to the Earth
• B) they resemble the Earth in a number of significant ways
• C) their atmospheres are very similar to the Earth in terms of their chemical make-up
• D) both have tantalized us when seen through a telescope -- one because it is perpetually covered by clouds, the other because it shows seasonal changes
• E) they each have a solid surface on which we can trace their geological history

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Definitions:

Regulatory Sequences

Segments of DNA that are involved in controlling the activity of genes, including when, where, and how much of a gene product is made.

Constitutive

Expressed continuously under normal physiological conditions, not subject to regulation by environmental conditions.

Lac Operon

A set of genes involved in the metabolism of lactose in bacteria, along with their promoter and operator sequences that control their expression.

Repressor Protein

A type of protein that binds to specific DNA sequences and inhibits the expression of a gene by blocking RNA polymerase.