Complete the following paragraph to describe the characteristics of mammals. chorion mammals, meaning the Most living mammals are extraembryonic membranes of the amniotic egg have been modified for wildly fluctuating development. consistent external contributes to the fetal portion of the placenta, while part contributes to the maternal portion The of the limbs four-chambered These mammals have adapted to life on land and have allow for fast movement. to placental internal hearts and expanded body temperatures Mammals have and they have uterine wall three-chambered 1Mammalc hava larna that are not ful teualna innn hirth external contributes to the fetal portion of the placenta, while part contributes to the maternal portion The of the limbs four-chambered These mammals have adapted to life on land and have allow for fast movement. to placental internal and hearts and expanded body temperatures Mammals have they have uterine wall three-chambered that are not fully developed upon birth Mammals have large therefore, offspring remain with their parents for a time after birth. brains marsupial lungs