Are any invertebrate nephridia (proto/meta) homologous with vertebrate kidneys in the sense that embryologically they also begin together with the genital system? When did the embryologic association ...
Cytoplasmic determinants are spread unevenly in the egg, and so when embryo starts forming (cells start dividing), the determinants are also unequally divided between cell. This unequal distribution ...
Usually adult organisms are more sophisticated than corresponding larva, i. e. frogs, mosquitoes, fish. Are there species where the opposite is true?