umbilical cord

long connecting mass between the developing embryo or fetus and the placenta: 'Do Klingon newborns cry when their umbilical cords are cut?'


organ in most mammals — supplies food and oxygen to the foetus and passes back waste during gestation — attached to the wall of the…


hard outer structure that provides both structure and protection to creatures such as insects and crustaceans (and perhaps exotic alien life). May also refer to…


the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs


often motile gamete which fertilizes the egg in sexual reproduction


lipid biomolecule synthesized by all animal cells; an essential component of animal cell membranes


the opening of the GI tract where solid waste is expelled


one of a set of lymphoid organs facing into the aerodigestive tract, which play an important role in the immune system


colourless, watery, coagulable bodily fluid which bathes the tissues and is carried by the lymphatic system into the bloodstream; it resembles blood plasma in containing…


neurotransmitter that plays several important roles in the brain and body, involved in motor control, hormone release, and perceived desirability or aversiveness of behaviors