Answer:
Option (d).
Explanation:
DNA is the genetic material of all the organism except some viruses. DNA is composed of nitrogenous base, deoxyribose pentose sugar and the phosphate group.
DNA replicatese by semi-conservative mode of replication in which one the daughter DNA consists of one newly synthesized strand and one parental strand. This mode of replication was explained by Messelson and Sthal experiment. The cells from 15N medium are transferred to 14N medium the band of intermediate density was observed. The daughter DNA consists of one 15N DNA strand and one 14N DNA strnd. This strand undergo replication in the 14N medium. This time one low density DNA band ( contains 14N - 14N DNA strand) and one intermediate density band ( 14N-15N DNA).
Thus, the correct answer is option (d).
Answer:
hurricane, tornado, drought, flood
Explanation:
The answer is <em>A.) You have antibodies that already recognize the virus</em>
Viruses and diseases are always changing. When we get sick with say the flu, a virus, or the cold of sorts, our body attacks it until it fights off the disease. You can't get sick from the same strand of sickness because once your body defeats the virus, it knows how to protect the body from it because of the antibodies, so the virus ends up evolving to get past your immune system again.
I hope this helped! Have a wonderful day :)