One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.
A replication bubble forms as the DNA unwinds.
Option C
<u>Explanation</u>:
Replication bubble is the space where the strands of double helical DNA structure are separated with the help of DNA helicase. The strands of the double helical DNA are still in the helix form on the both end of the unwinded DNA stand which gives this region an appearance of a bubble.
DNA unwinding is the first step in replication or transcription of the DNA molecule. DNA helicase separates the two types of "DNA" that are connected by hydrogen bonds with the help of ATP hydrolysis.
Answer:
the answer is all of the above
<span>Bone marrow which is located <span>within the spongy or cancellous portions of bones is the essential site of new blood cell production or hematopoiesis. Bone marrow contains stem cells which able to differentiate into specialized cell types. People with diseases like blood cancers, such as leukaemia and lymphoma, sickle cell anaemia, and other rely on bone marrow transplantation to survive.</span></span>
