A contraceptive pill prevented pregnancy in 99% of users with perfect use and 91% with typical use over one year.
Which explanation best accounts for the difference?
Some typical users missed tablets, reducing reliable suppression of ovulation.
Some perfect users missed tablets, increasing reliable suppression of ovulation.
Some typical users missed tablets, increasing reliable suppression of ovulation.
Some perfect users missed tablets, reducing reliable suppression of ovulation.
48 exam-style questions on Edexcel GCSE Biology 7.2 Reproductive hormones, covering 7.2.1 Stages of the menstrual cycle, 7.2.2 Hormonal control of the menstrual cycle, 7.2.3 Hormonal contraception, 7.2.4 Evaluating contraception methods, and 7.2.5 Hormones in Assisted Reproductive Technology. Each one has a worked solution and a mark scheme showing where the marks go.