The subarachanoid space lies between the arachnoid and pia mater. It is filled with cerebrospinal fluid. All blood vessels entering the brain, as well as cranial nerves pass through this space. The term arachnoid refers to the spider web like appearance of the blood vessels within the space.
Why do biologists organize living things into groups? What do the levels of classification indicate about the relationship between organisms? What characteristics are used to classify organisms into domains and kingdoms? What is the scientific study of how living things are classified called? Taxonomy
Science is the field of study concerned with discovering and describing the world around us by observing and experimenting. Biology, chemistry, and physics are all branches of science. Science is an empirical field, that is, it develops a body of knowledge by observing things and performing experiments. The meticulous process of gathering and analyzing data is called the scientific method, and we sometimes use science to describe the knowledge we already have.