Answer:
long cold winters, with annual temperatures mostly below freezing.
DescriptionPopulation density is a measurement of population per unit area, or exceptionally unit volume; it is a quantity of type number density. It is frequently applied to living organisms, most of the time to humans. It is a key geographical term.
Answer:
This is called wind shear, and it can induce a spinning movement in the air. At first this creates a spinning cylinder of air that is parallel to the surface. But as with any thunderstorm, the convective cells in a hurricane create strong updrafts. These can tilt the spinning air upright; a tornado is born.
Answer:
AZT is a thymidine analog
Explanation:
Azidothymidine (AZT) is an antiviral drug used for the treatment of the Human immunodeficiency virus infection (HIV/AIDS) by preventing the transmission of HIV from infected cells. AZT is capable of suppressing the activity of the enzyme reverse transcriptase of the retroviral HIV genome, which enables it to copy RNA into DNA. In infected cells, this double-stranded DNA is integrated into the host genome which is then instructed to produce identical HIV copies. AZT is a thymidine analog that is incorporated into DNA and thus interferes with DNA synthesis, thereby inhibiting cell proliferation.
All of the above are needed. Nucleotides are the basic building blocks of new DNA, ATP energy is needed because replication is an active process, and enzymes catalyze the reactions needed to carry it out (e.g. helicase to separate the strands to be replicated, DNA polymerase to build the new strands, and ligase to "glue" the fragments together).