Gills are rich in blood vessels that bring blood close to the surface for gas exchange, the respiratory function. The circulatory system then carries the oxygen from the gills to the cells of the body, providing the cells with the necessary oxygen to carry out cellular respiration.ills are rich in blood vessels that bring blood close to the surface for gas exchange, the respiratory function. The circulatory system then carries the oxygen from the gills to the cells of the body, providing the cells with the necessary oxygen to carry out cellular respiration.
In geology, rock or stone is a naturally occurring solid aggregate of one or more minerals or mineraloids. For example, the common rock granite is a combination of the quartz, feldspar and biotite minerals. The Earth's outer solid layer, the lithosphere, is made of rock.he types and abundance of minerals in a rock are determined by the manner in which the rock was formed. Many rocks contain silica (SiO 2); a compound of silicon and oxygen that forms 74.3% of the Earth's crust.
Precambrian rocks rock,aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classesâigneous, sedimentary, and metamorphic......he rocks of this region, and of the early Precambrian as a whole, are generally granite granite,coarse-grained igneous rock of even texture and light color, composed chiefly of quartz and feldspars. It usually contains small quantities of mica or hornblende, and minor accessory minerals may be present......