International A Level Biology / Gene expression and genetics
Genetic screening: carriers, PGD and prenatal tests revision notes
Edexcel International A Level Biology (YBI11), chapter 6: Gene expression and genetics, specification point 2.17. Part of the full course.
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Genetic screening tests DNA for particular alleles at different stages, from checking adults for carrier status to testing an embryo or fetus. Knowing what each test involves helps you compare the choices and understand their possible outcomes.