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.
An oocyte (UK /ËoÊÉsÊÉªt/ , US /ËoÊ.oÊ.saÉªt/), ooecyte, oÃ¶cyte, ovocyte or rarely, ocyte is a female gametocyte or germ cell involved in. Reproduction in other, words it is an immature, ovum or egg. Cell an oocyte is produced in the ovary during female. gametogenesisuring the primary oocyte stage of oogenesis, the nucleus is called a germinal vesicle. The only normal human type of secondary oocyte has the 23rd (sex) chromosome as 23,X (female-determining), whereas sperm can have 23,X (female-determining) or 23,Y (male-determining).