Have to have submitted today! i will give brainleiest 1. explain a placental mammal. 2. describe the female reproductive system in a human. 3. describe the male reproductive system in a human. 4. explain how a zygote develops and how a developing embryo is protected in a human.

1.mammalian group 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. The placentals include all living mammals except marsupials and monotremes.

2.In the human the female reproductive system is immature at birth and develops to maturity at puberty to be able to produce gametes, and to carry a fetus to full term. The internal sex organs are the uterus, Fallopian tubes, and ovaries. ... The vagina is connected to the uterus at the cervix.

3.The purpose of the organs of the male reproductive system is to perform the following functions: To produce, maintain, and transport sperm (the male reproductive cells) and protective fluid (semen) To discharge sperm within the female reproductive tract during sex.

4.The zygote develops first into an embryo and then into a fetus. From the two-cell stage through the eighth week of development, the developing human is called this. From about the ninth week of development until birth, the developing human is called this. How is the developing embryo protected and nourished.

your answer is "the 1950's"

and after water is usually warmed by the sun the water temperature raises and then evaporates .