成语大全网 - 成语解释 - 用英文一句话描述下列项:mammary gland、diaphragm、monotreme、marsupial、gestation period 下面还有:

用英文一句话描述下列项:mammary gland、diaphragm、monotreme、marsupial、gestation period 下面还有:

mammary gland

Mammary glands are the organs that, in the female mammal, produce milk for the sustenance of the young.

diaphragm

A muscular membranous partition separating the abdominal and thoracic cavities and functioning in respiration.

monotreme

A member of the Monotremata, an order of primitive egg-laying mammals restricted to Australia and New Guinea and consisting of only the platypus and the echidna.

marsupial

any mammal of the order Marsupialia, in which the young are born in an immature state and continue development in the marsupium.

gestation period

The Gestation period in a viviparous animal is the length of its gestation. In humans this is 266 days (38 weeks), but varies for other animals.

placental mammal

ny member of the mammalian group (cohort Placentalia) characterized by the presence of a placenta, which facilitates exchange of nutrients and wastes between the blood of the mother and that of the fetus.

placenta

the vascular organ in mammals except monotremes and marsupials that unites the fetus to the maternal uterus and mediates its metabolic exchanges through a more or less intimate association of uterine mucosal with chorionic and usually allantoic tissues.