Out of the following give choices;
a. All DNA strands
contained only the heavy nitrogen isotope.
b. Half of the DNA strands contained only the light nitrogen
isotope.
c. All DNA strands contained both heavy and light nitrogen
isotopes.
d. All DNA strands contained only the lighter nitrogen
isotope.
The answer is b. Meselson–Stahl experiment demonstrated the semi-conservative model of DNA replication.
When DNA is replicated, one strand of the new double
helix strand is the parent's strand while the other is the newly synthesized
one. This made the semiconservative model stand out over the other two, dispersive
and conservative models.
Likely, B is the expected answer.
_____
As one who has suffered health problems for more than 40 years due to the desire of certain chemical industries to make money by polluting my food, I can barely remain civil when discussing genetic modification. Plants with built-in pesticides are bad news on so many levels it would take a library of books to discuss them all. What, after all, is the benefit of efficiently producing poison?
C.
The skeletal system provides structure to the human body.
He is using an arthroscope. Which is use to examine a joint.
