The membrane is selectively permeable because substances do not cross it indiscriminately. Some molecules, such as hydrocarbons and oxygen can cross the membrane. Many large molecules (such as glucose and other sugars) cannot. Water can pass through between the lipids.
The answer would be D.: <span>Helicases separate the two strands of the double helix, and DNA polymerases use each of the original strands as templates to create two new strands. :)</span>
To ensure that the drinking
water for the public is safe, the Safe Drinking Water Act (SDWA) is
promulgated. The EPA is required to set standards for drinking water quality
and oversee all states in the area are implementing these standards.
Mutagen is an agent that causes DNA mutations. UVA radiation penetrates deep into the skin and acts as a mutagen. UV light is the most common source of radiation that affects DNA, but it is a weak radiation and it penetrates only the surface cells of your skin.
