Answer:
Implantation is what leads an egg to pregnancy. If implantation doesn’t occur then, the fertilized egg comes out with period blood. After fertilization, the egg undergoes series of divisions called cleavage. The cells remain enveloped in the protective egg membrane. This membrane layer hardens after entry of sperm.
<em>hope this helps :)</em>
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I think it is also all the above so D
Answer:
How Does It Work? Most birth control pills are "combination pills" containing a mix of the hormones estrogen and progesterone to prevent ovulation (the release of an egg during the monthly cycle). A woman cannot get pregnant if she doesn't ovulate because there is no egg to be fertilized. The answer is D.