Answer:
Genetic variation
Explanation:
Genetic variability (diversity) stems from two basic processes: mutation and recombination.
If there were no mutations, all genes would exist in only one form, they would not have alternative forms.
Since phenotypic variability also depends on genetic variability, it is clear that the processes of mutation and recombination contribute to the creation of a large number of different phenotypes.
Answer:
Crossing over
Explanation:
During prophase I of meiosis, homologous chromosomes pair to form bivalents. The chromatids of bivalents may form intimate contact points called chiasmata. At the chiasmata breakage may occur and exchange of chromatids segments between non sister chromatids may take place. This is crossing over ad results in new gene combinations causing variations.
You mean a trench like marianas trench that type of gash?
Answer: Unzipping of DNA refers to the unwinding of DNA duplex from specific site that initiate the replication process (called origin of replication). Replication of DNA requires a single strand template so that DNA polymerase can add nucleotides in order to make new DNA copy.
Therefore, DNA must unzip so that template strand is available for making new DNA.
