Glossary of Terms. Bronchus / Bronchi / Bronchioles. The airways of the lungs. When a person takes in a breath of air, the air travels through the nose or mouth, into the larynx, then into the trachea, which is the main passageway into the lungs. The trachea divides into a right and left main bronchus.
Plant and animal life, atmosphere and water are the major causes of weathering. Weathering breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering: mechanical and chemical.
Physical weathering is a process that breaks up and disintegrates parent rock, or primary minerals, within the earth. In the tropics, physical weathering is caused by the wetting and drying of rocks; erosion; actions of plants and animals; or the falling, smashing, or breaking of rock materials into smaller pieces.