two
A DNA molecule consists of two long polynucleotide chains composed of four types of nucleotide subunits.
Answer:
The biggest advantage is that they have a higher resolution and are therefore also able of a higher magnification (up to 2 million times). Light microscopes can show a useful magnification only up to 1000-2000 times. This is a physical limit imposed by the wavelength of the light.
Explanation:
Hope I <em><u>Helped!</u></em> :D
Answer:
many
pollution by dumping chemical that are harmful to the animals
littering by plastic
accidentally introducing invasive species
over fishing
it lowers the biodiversity of the aquatic ecosystems living there
Explanation:
The results will most likely be valid because the scientists kept getting the same results after REPEATED experiments. If they just conducted one experiment then they would not have been sure if what happened was a fluke or if another thing would happen after another experiment.<span />