B. I think correct answer
for question 1.) i am pretty sure of answer a.)
for question 2.) the answer is most likely b.)
i would recommend waiting for a second opinion. just to be safe.
The answer is speciation by geographic isolation. When the population of a species gets separated due to reasons such as continental drift, mountains, canyons, etc. then each separated group of population may survive and adapt to their respective environment leading to speciation. These barriers do not allow the evolving populations to interbreed initially and over time when they evolve into different species they become completely reproductively isolated.
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.
