useless trivia: What Word Means: Referring To A Portal Vein?

Questions

To a human, one giant octopus looks virtually the same as any other of the same size and species. This explains why divers claim to have seen the same octopus occupy a den for ten or more years. But an octopus seldom lives longer than ----------?

The ---------- is the only bird that can swim, but not fly. It is also the only bird that walks upright.?

To survive, most birds must eat at least half their own weight in food ----------?

The ---------- is a little-known burrowing South American animal that is related to the armadillo, but is smaller in size. The ending of the animal's name is derived from the Spanish ciego, meaning "blind."?

The female ---------- inseminates herself. At mating time, the male deposits a conical mass of jellylike substance containing the sperm. The female draws the jelly into herself, and in so doing, fertilizes her eggs.?