Ch. 27 Development and Heredity
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Problem L2.1
The prenatal period typically lasts 38 weeks. From the clinical viewpoint, a pregnancy typically lasts 40 weeks. What is the reason for this difference?
Problem L2.2
Why is the single-celled zygote approximately the same size as the multicellular blastocyst before it implants in the uterine wall?
Problem L2.3
Why do most spontaneous abortions occur in the first trimester?
Problem L2.4
Explain why many pregnant women frequently feel the urge to urinate during their last trimester.