Answer:
Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water. Crystallization, erosion, sedimentation, and metamorphism transform one rock type into another or change sediments into rock. The rock cycle describes the transformations of one type of rock to another. The process by which a rock changes form or mineral content as a result of environmental changes such as heat and pressure. a rock that was altered by metamorphism.
Answer: A y B son correctas
Explanation:
Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
Mitosis
Definition of Mitosis: <span>The process where a </span>single cell<span> divides resulting in generally two identical </span>cells<span>, each containing the same number of </span>chromosomes<span> and genetic content as that of the original </span>cell<span>.</span>
Answer:
Ozone layer... pollution
Explanation:
The ozone layer is a layer in the atmosphere which provides a barrier between harmful UV rays and the Earth. However, pollution is quickly depleting the layer which in turn creates a higher risk of skin cancers and other conditions caused by harmful UV rays.