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.
Essentially, a combustible dust is any fine material that has the ability to catch fire and explode when mixed with air. Combustible dusts can be from: 1  most solid organic materials (such as sugar, flour, grain, wood, etc. ).2  many metals, and.ssentially, a combustible dust is any fine material that has the ability to catch fire and explode when mixed with air. Combustible dusts can be from: 1  most solid organic materials (such as sugar, flour, grain, wood, etc. ). 2  many metals, and.