Chapter 43.5, Problem 3R

Summary Introduction

To review:

The embryo of the first trimester is sensitive to environmental risks.

Introduction:

In mammals, pregnancy occurs when the fertilized egg (zygote) gets implanted in the endometrium of the mother’s uterus. The period of bearing the developing embryo or fetus inside the womb till its birth is referred to as gestation. In humans, the gestation period is categorized into three trimesters, each having a period of three months.