The wild-type nematode Caenorhabditis elegans has a bent body with the shape of a wave. In the presence of increasing concentrations of ethanol, however, the body bend is progressively diminished. Loss-of-function mutations in SLO-1, a gene that codes for an ion channel, confer ethanol resistance and allow the worm to maintain its body bend up to higher ethanol concentrations. The channel function is defined based on the ability of the channel to conduct ions across the membrane. According to these observations, would you expect the channel to open or close in the presence of ethanol in wild-type worms? Would a gain-of-function mutation in SLO-1 tend to increase or decrease body bend?
A) Open; increase
B) Open; decrease
C) Close; increase
D) Close; decrease

Question

Quizplus · Accepted Answer

The loss-of-function mutations in SLO-1 partially close the channel, an effect opposite to that of ethanol.

The Wild-Type Nematode Caenorhabditis Elegans Has a Bent Body with the Shape