A heat engine gives greater efficiency when run with a large temperature difference. In the oceans the temperature difference between surface and deep water is greatest in the tropics, although still a modest 20 to 25 Â°C.
A blastocyst is a cellular mass that forms early in the process of embryo development in mammals. In humans, this stage of embryogenesis occurs five days after fertilization, when there are fewer than 100 cells in the mass.
The choroid plexus (CP) (from Greek khorion membrane enclosing the fetus, afterbirth; plexus: Mod.L., lit. braid, network) is a plexus of cells that produces the cerebrospinal fluid in the ventricles of the brain.here is also choroid plexus in the fourth ventricle, in the section closest to the bottom half of the cerebellum. The choroid plexus consists of many capillaries, separated from the ventricles by choroid epithelial cells. Fluid filters through these cells from blood to become cerebrospinal fluid.