Answer:
B. Nucleic acids absorb UV light maximally at wavelengths of 254 to 260. Proteins absorb UV maximally at 200 nm. Using this phenomenon, one can to determine the presence and concentration of nucleic acids in a mixture.
Explanation:
The concentration of a solution of nucleic acid can be determined by measuring the absorbance at 260 nm, using a spectrophotometer. An A260 of 1.0 is equivalent to a concentration of 50 μg/mL for double-stranded DNA, or 40 μg/mL for single-stranded DNA or RNA. If the A280 is also determined, the A260/A280 ratio indicates if there are contaminants present, such as residual phenol or protein. <u>The A260/A280 ratio should be around 1.8 for pure DNA and 2.0 for pure RNA preparations.</u>
Answer:
A: Shared characteristics are features or qualities that organisms or species have in common.
C: Shared characteristics can be characteristics that existed in the common ancestor and still exist in modern organisms.
D:Shared characteristics can be new characteristics that have been modified from what was found in the common ancestor.
Answer:
About 20 percent of all oxygen produced comes from the Amazon.
Answer:
It can be things like bleach, soap, or vinegar.
Explanation: