Diffusion Across a Cell Membrane. Diffusion is the movement of a substance across a membrane. Substances diffuse across cell membranes in a process known as passive transport. This means that the cell does not expend any energy in transporting substances across the cell membrane. Instead, substances move down their concentration gradient as a result of random thermal motion.
401k and profit sharing plans are both forms of retirement plans. They allow employees to make pre-tax contributions to an account where contributions and earnings are not taxed until distributed. Some 401k plans require an employer to make contributions to a plan.
Taxable and Non-taxable Allowances. Iâve noticed some questions on Yahoo answers about which allowances are taxable and which are not. At the current time, the only taxable allowance is CONUS COLA, the Cost of Living Allowance paid to people who living in certain expensive parts of the continental United States. By federal law, all new allowances created after 1986 will be taxable.