Which of the following would be the latest in the development of a human fetus?

bone starts to replace cartilage to form the beginnings of a skeleton

the fetus grows to reach approximately eight centimeters in length

cells divide into the endoderm, mesoderm, and ectoderm

the nervous system begins to develop and can control basic body functions

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c