Composite Volcano: S<span>teep sided cones formed from layers of ash and lava flows.</span>
Dome Volcano: Roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano
Shield Volcano: A broad domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava.<span />
Different forms of a given gene are known as "alleles". Alleles are essential for the formation of life and add to diversity both within and outside the organism itself in many ways.
I believe the answer is B.
Crustacea(ns) form a very large group of arthropods.
