Which of the following is not included in the first trimester? a. heart begins beating b. arm and leg buds appear c. umbilical cord develops d. eyes and brain complete formation

The first trimester begins on the first day of the last period and lasts until the end of week 12. During this trimester, the baby grows faster than at any other time. By six weeks, a heartbeat can usually be heard and by the end of week 12 the baby's bones, muscles and all the organs of the body have formed. The following is NOT included in the first trimester: Eyes and brain complete formation. Correct D

what effect does exercise have on the nervous system?

the answer is c.

answergenetic engineering;