Manus (anatomy) The manus (Latin for hand) is the zoological term for the distal portion of the fore limb of an animal. In tetrapods, it is the part of the pentadactyl limb that includes the metacarpals and digits (phalanges). During evolution, it has taken many forms and served a variety of functions.
A cross between parents that differ in one trait is called monohybrid cross.
A crucial piece to the puzzle in figuring out how siblings can look so different when they come from the same parents has to do with how genes are passed down. Which of your parents' two gene copies you end up with is chosen at random.