Sedimentary Rock Examples. Common clastic sedimentary rocks are listed on the table below. They are listed by grain size in decending order. Grain size is one factor in classifying sedimentary rocks .Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window.
THE PROKARYOTIC CELL: BACTERIA. 1. There are three basic shapes of bacteria: coccus, bacillus, and spiral. 2. Based on planes of division, the coccus shape can appear in several distinct arrangements: diplococcus, streptococcus, tetrad, sarcina, and staphylococcus.acterial cell shape is determined primarily by a protein called MreB. MreB forms a spiral band â a simple cytoskeleton â around the interior of the cell just under the cytoplasmic membrane. It is thought to define shape by recruiting additional proteins that then direct the specific pattern of bacterial cell growth.
Different Size, Shape and Arrangement of Bacterial Cells. Bacteria are prokaryotic, unicellular microorganisms, which lack chlorophyll pigments. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Due to the presence of a rigid cell wall, bacteria maintain a definite shape, though they vary as shape, size and structure. When viewed under light microscope, most bacteria appear in variations of three major shapes: the rod (bacillus), the sphere (coccus) and the spiral type (vibrio).