both refer to movie chains (i.e., Loews, AMC Theatres) with movie theatres that screen more than one film at a time, as opposed to single-screen theatres. A multiplex has from 2 up to 16 screens, a megaplex has 16 or more screens; plex is the abbreviation for a multiplex theatre.
A morula (Latin, morus: mulberry) is an early stage embryo consisting of cells (called blastomeres) in a solid ball contained within the zona pellucida.
Blastula: It is an early form of an animal embryo that develops from a morula, consisting of a sphere of cells with a central cavity. It is also called blastosphere. More to Know: Embryogenesis is the process of development of zygote into an embryo.