Simply put, a genetic mutation comes from a change in the DNA; this change can result from an extrachromosomal element, an alteration of the inherited nucleotide...
The basic building block of nucleic acids, such as DNA and RNA. It is an organic compound made up of nitrogenous, a sugar, and a phosphate group (http://www.biology-online.org/dictionary/Nucleotide)
3) decrease
Without the green house effect, earth would be like a solid ball of ice and rock.
Life as we know it wouldn't exist without greenhouse gases.
The temperature would drop below 0° Fahrenheit!
Answer:
D. "always" cover the microscope when not in use.
Explanation:
when you are finished using a light microscope or any microscope in general you always need to put the cover back on it. Mostly, to protect it from any harmful bacteria, light etc. and to keep it clean and, from collecting dust.