Which structure is the site of nutrient and gas exchange between the mother and a growing fetus? a. placenta b. umbilical cord c. fallopian tube d. uterus

A). Placenta

Explanation:

During pregnancy, the embryo formed as a result of zygote growth produced from fertilization is implanted in the UTERUS or WOMB of the female. The developing fetus is strictly dependent on the mother for all the substances it needs to survive. These substances reach the fetus via a structure present in the uterus. This structure is called PLACENTA.

Placenta is the connection between the mother and the developing fetus. It is an organ that helps the mother supply required nutrients and oxygen via the umbilical cord to the fetus. It also helps remove waste products from the fetus into the mother's blood. Hence, the PLACENTA is the site of nutrient and gas exchange (oxygen and CO2) between the mother and the fetus.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.