Problem 1: Number of chromosomes. A human cell has 46 total or 23 pairs of chromosomes. Following mitosis, the daughter cells would each have a total of ______ chromosomes. After meiosis I, the two daughter cells would have _____chromosomes, and after meiosis II ______ chromosomes.
The permissible exposure limit (PEL or OSHA PEL) is a legal limit in the United States for exposure of an employee to a chemical substance or physical agent.For chemicals, the chemical regulation is usually expressed in parts per million (ppm), or sometimes in milligrams per cubic meter (mg/m 3). TWA is the average exposure over a specified period of time, usually a nominal eight hours. This means that, for limited periods, a worker may be exposed to concentration excursions higher than the PEL, so long as the TWA is not exceeded and any applicable excursion limit is not exceeded.
Below is some information on the major occupational exposure values. Permissible Exposure Limits (PELs): The Occupational Health and Safety Administration (OSHA) has set permissible exposure limits (PELs) on the amount or concentration of a substance in the air.ome of the PELs are listed as ceiling values â concentrations above which a worker should never be exposed, or short-term exposure limits (STELs) âaverage concentrations which should not be exceeded over a 15 minute time period. It is important to note that the PELs tend to be higher than other published values.