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 blastocoel is the fluid-filled cavity of the blastocyst that plays an important part in gastrulation later on. The blastocyst is the ball of cells that forms about 5 days â¦ after an egg is fertilized.