The replication fork is a structure that forms within the nucleus during DNA replication. It is created by helicases, which break the hydrogen bonds holding the two DNA strands together. The resulting structure has two branching "prongs", each one made up of a single strand of DNA.
Answer:
It's 3!
Explanation:
There must be genetic differences so the best fitted organisms will survive. If they were all the same then no one would be best fitted and Natural Selection wouldn't be able to occur
It's not 1 because a food shortage isn't required, there's always competition for food sources
It's not 2 because there doesn't need to be a change in the environment for natural selection, just for evolution.
And it can't be 4 if 1 and 2 are wrong!
Hope this helped!
C. nerve cells.............................
The answer is the cell membrane. The cell membrane controls what nutrients come in, and what unneeded material comes out. It protects the cell from anything that might come in and harm it. It is kind of like the security guard. A security guard let's the good people in and keeps the bad people out.
