RESUMO
Some aspects of the anatomical and physiological sexual dimorphism in mammals have been studied. In order to study the placental sexual diomorphism, the enzymatic activie of alkaline phosphatase [ALP] in embryo and its placenta was investigated. In the present study a group of 75 adult female white mice [australian strain] in the same age were used. The animals were divided in to control and experimental groups. All female mice were mated with males of the same strain and age [one mae /three female] and were kept in controlled conditions. the experimental group 1 animals were studied in days 10 to 14 and group 2 in days 15 to 19 of pregnancy. From the day 10 to 19 of gestation, every day 6 pregnant mice were sacrified and two embryos from each part of the uterus were extruded to assay enzymatic activity of ALP in embryo and placenta. from day 15 to 19 sex determination of embryos was established. the resultes indicated that the rate and developmental pattern of ALP activity in placenta revealed a significant difference in male and female [p