In biology conception is the coalescence of the male and female generative elements, producing pregnancy.
The proof of a coalescence of the second male nucleus with the definitive nucleus gives the conception a more stable basis.
In the absence of dust and greasy contamination, the obliquely colliding jets may rebound from one another without coalescence for a considerable time.
In some hydroids the founder-polyp, developed from a planula after fixation, throws out numerous outgrowths from the base to form the hydrorhiza; these outgrowths may be radially arranged so as to form by contact or coalescence a flat plate.
By coalescence of the endoderm-layers, the coelenteron may be reduced to vessels, usually eight in number, opening into a ring-sinus surrounding the pore.