Sex Chromosomes. Sex chromosomes are particular chromosomes that are involved in determining the sex of an organism. In the cells of humans and many other organisms the sex chromosomes consist of a pair of chromosomes called the X and Y chromosomes. The X and Y chromosomes were first discovered in beetles by Nettie Stevens in 1906.
What makes up household dust: 1  Dead skin cells. 2  Live dust mites. 3  Dead dust mites and dust mite feces.  Pollen and 1  allergens. Combustion byproducts (smoke)  Clothing 1  fibers. Pesticide residue.
Dust cells are another name for monocyte derivatives in the lungs that reside on respiratory surfaces and clean off particles such as dust or microorganisms. Alveolar macrophages are frequently seen to contain granules of exogenous material such as particulate carbon that they have picked up from respiratory surfaces. Type I pneumocyte (Squamous Alveolar) cells that form the structure of an alveolar wall. 2  Type II pneumocyte (Great Alveolar) cells that secrete pulmonary surfactant to lower the surface tension of water and allows the membrane to separate, thereby increasing the capability to exchange gases.