Answer: After 3 rounds, 8 segments having 2 original strands on different segments will be present.
Explanation:
The polymerase chain reaction selectively and repeatedly copy the double stranded DNA (dsDNA) in the PCR machine.
1st round:
Single piece of double stranded DNA (dsDNA) unwinds in two seperate strands, before complementary nucleotides are synthesized to establish double helix.
2nd round:
The two dsDNA yields 4 segments before complementary nucleotides are synthesized
3rd round:
The four dsDNA yields 8 segments before complementary nucleotides are synthesized.
Therefore, at the end of 3 rounds, the two original strands will be present on the 8 different segments of copied DNA.
There are two types of succession that lead to the increasment of the ecosystem:
1. Primary succession is the change in the structure of an ecosystem represented with the increase of the ecological community on an area that has not been previously occupied by an ecological community such as area after the lava flow or glacial lake. The first organisms of primary succession are pioneer plants usually, lichens and mosses.
2. Secondary succession includes the step of removal of pre-existing community and after that, colonization of the new one.
An example could be oil (olive, almond)
Answer: Point mutation is easily reversible, thus non-lethal
Explanation:
Point mutation is caused by exchange of a single nucleotide for another. These change is called
1) Transition (when a purine base substitute another purine base, or pyrimidine bases substitute each other)
2) Transversion (when a purine base substitute a pyrimidine base).
However, note that a point mutation can be easily reversed by another point mutation; so, the claim that a nucleotide difference in the Hsr12 gene caused the human disease is inaccurate
