Why are some mutations of ras associated with cancer?

RAS belongs to a family of genes that make proteins involved in cell signaling pathways that control cell growth and cell death. Mutated, or deformed cells of the RAS gene may be found in some types of cancer.

Oncogenes are genes that are closely linked to cancer, and the gene that encodes RAS was among the first to be discovered.

Explanation:

A cancer-causing mutation of RAS makes up a form of the protein that is always on. These proteins continually tell the RAS continually that the cancer cells that are okay to multiply, without the normal limits that control cell growth.

answer and explanation;

volcanic rocks are igneous rocks which form from lava, molten rock which has been thrust out of a volcano onto the surface of a rocky body such as an asteroid, planet, or dwarf planet.  

plutonic rocks are igneous rocks which form from subterranean chambers of molten rock or magma. plutonic rocks make up the base of continental crust as well as oceanic crust. their slow rate of formation causes them to be coarse grained since there is plenty of time for large crystals to form before the magma solidifies into rock.

the textural difference is that plutonic rocks are more coarse grained than volcanic rocks. plutonic rocks are coarse grained while volcanic are fine grained ; glassey or fragmental. since fine and coarse are adjectives the decision as to whether a rock is fine or coarse grained is generally made on the bases of whether or not the individual crystals can be seen in most if the rock.