<p><span style="font-size: 16px;">Pregnancy begins with the fertilization of an egg and continues through to the birth of the individual. The length of time of <span data-type="term">gestation</span> varies among animals, but is very similar among the great apes: human gestation is 266 days, while chimpanzee gestation is 237 days, a gorilla’s is 257 days, and orangutan gestation is 260 days long. The fox has a 57-day gestation. Dogs and cats have similar gestations averaging 60 days. The longest gestation for a land mammal is an African elephant at 640 days. The longest gestations among marine mammals are the beluga and sperm whales at 460 days.<span id="fs-idm35440016" style="box-sizing: border-box; display: block; margin: 0px; text-align: center; color: #555555; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 20px;" data-type="media" data-alt="Photo shows a human fetus, with a large bent head and a dark eye, fingers on its arm and a leg bud. The spine is visible through the back, and the stomach protrudes out as far as the leg bud."><img src="http://cnx.org/resources/3df130622fbcd866ef849639a598279387b9527b/Figure_43_07_02.jpg" alt="Photo shows a human fetus, with a large bent head and a dark eye, fingers on its arm and a leg bud. The spine is visible through the back, and the stomach protrudes out as far as the leg bud." width="230" style="box-sizing: border-box; vertical-align: middle; max-width: 100%;" data-media-type="image/jpg" /></span>Fetal development is shown at nine weeks gestation. (credit: Ed Uthman)</span></p> <p style="margin: 1em 0px; padding: 0px; outline: 0px; word-wrap: normal; line-height: 16.8px; word-break: normal;"><strong style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px; line-height: 1.4;">Complete the tasks on the list below:</span></strong></p> <ul style="outline: 0px; word-wrap: normal; word-break: normal; line-height: 16.8px;"> <li style="margin: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px; line-height: 1.4;">Read the following page in the OpenStax textbook</span></li> <ul style="outline: 0px; word-wrap: normal; word-break: normal;"> <li style="margin: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px;"><a href="http://cnx.org/contents/GFy_h8cu@10.53:NCKit53u@3/Human-Pregnancy-and-Birth">Human Pregnancy and Birth</a> </span></li> <ul style="outline: 0px; word-wrap: normal; word-break: normal; line-height: 16.8px;"> <li style="margin: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px;">Read the entire page</span></li> </ul> </ul> <li style="margin: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px;">Use the Glossary at the bottom of the page to help with the vocabulary for this week</span></li> <li style="margin: 0px; outline: 0px; word-wrap: normal; word-break: normal;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px;">Use the Review Questions and Free Response questions to check for understanding</span></li> </ul> <p style="margin: 1em 0px 0px; padding: 0px; outline: 0px; word-wrap: normal; line-height: 16.8px; word-break: normal; text-align: right;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-size: 16px;"><span style="margin: 0px; padding: 0px; outline: 0px; word-wrap: normal; word-break: normal; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 14px; line-height: 20px;">Download for free at <a class="sExtlink-processed" style="margin: 0px; padding: 0px; outline-width: 0px; word-wrap: normal; color: #3a549a; word-break: normal;" href="http://cnx.org/contents/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.53">http://cnx.org/contents/185cbf87-c72e-48f5-b51e-f14f21b5eabd@10.53</a></span></span></p>