Consider the Ras Signal-Transduction Pathway

question 47

Multiple Choice

Consider the Ras signal-transduction pathway. Suppose that a mutation occurred within the gene that encodes the transmembrane receptor protein. Which of the following types of mutations in this receptor could lead to cancer?

• A) a mutation that allows the receptor to become phosphorylated in the absence of a growth factor bound to it
• B) a mutation in the extracellular domain that prevents the binding of a growth factor
• C) a mutation in the transmembrane domain that prevents the signal from being transduced to the interior of the cell
• D) a mutation within the intracellular domain that prevents interaction with the adaptor molecules
• E) All of these are types of receptors mutations that could lead to cancer.

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Definitions:

Conventional Tillage

A traditional method of farming that involves plowing, harrowing, and preparing the soil before sowing seeds.

Erosion

The process by which soil, rock, or dissolved material is worn away and removed from one location to another by wind, water, or other natural agents.

Polyvarietal Cultivation

The agricultural practice of growing multiple varieties of the same crop in a given area to increase genetic diversity and reduce disease risk.