â¢ Medium-grained (1/16 mm to 2 mm) rocks are usually called sandstone. Medium-grained rocks can be composed of quartz grains, feldspar grains (arkose), or rock fragments and clay (graywacke). Sandstone (Photograph by Parvinder Sethi). Medium-sized grains in clastic sedimentary rocks form sandstone. This sample is a quartz sandstone.
Eukaryotes are those organisms in which the cell body contains a nucleus whereas prokaryotes are those organisms in which the cell body does not contain a nucleus. In amoeba, the reproduction is carried out under the instruction of the nucleus thus making it a eukaryote organism.
Most prokaryotes have a single loop of DNA for their genome while most eukaryotes have multiple pieces of linear DNA (the packaging of the DNA is also different between eukaryotes and prokaryotes). There are also significant differences between eukaryotic and prokaryotic ribosomes.ost prokaryotes have a single loop of DNA for their genome while most eukaryotes have multiple pieces of linear DNA (the packaging of the DNA is also different between eukaryotes and prokaryotes). There are also significant differences between eukaryotic and prokaryotic ribosomes.