A lymphocyte is a type of white blood cell. White blood cells are part of your immune system and help your body fight off diseases, including infections and cancer. There are two main types of lymphocytes â B cells and T cells. B cells make antibodies that attack bacteria and toxins in the body.
- Mud, sand, and volcanic ash can make sedimentary rocks. bones leaves, stems, and other remains of living things. - Geologists classify metamorphic rocks according to the arrangement of the grains that make up the rock. - Metamorphic that have their grains arranged in parallel layers or bands are said to be foliated.
Clastic sedimentary rocks are composed of other rock fragments that were cemented by silicate minerals. Clastic rocks are composed largely of quartz, feldspar, rock (lithic) fragments, clay minerals, and mica; any type of mineral may be present, but they in general represent the minerals that exist locally.