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.
Extrusive, also known as volcanic, rocks are a type of igneous rock that form at the crust's surface as a result of volcanic activity. This type of rock occurs when lava flows on or above the Earth's surface and cools down rapidly.