The answer that best fits the blank is RENDERS CILIA IMMOBILE. What happens when the left-right asymmetries in humans are reversed would lead to a genetic condition that renders cilia immobile. This is based on the role of the ciliated cells in the body that has an important impact in one's biological development.
Likely, B is the expected answer.
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As one who has suffered health problems for more than 40 years due to the desire of certain chemical industries to make money by polluting my food, I can barely remain civil when discussing genetic modification. Plants with built-in pesticides are bad news on so many levels it would take a library of books to discuss them all. What, after all, is the benefit of efficiently producing poison?
The bloomers fashion included an amalgamation of dress and trousers as a fashion trend during the height of civil rights clamor. The clothes were castigated by men for they feared a reversal of gender roles. Only men were allowed to wear trousers during the time.
This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group, the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time.