Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
Out of the choices given, the excerpt that best reflects Byron's appreciation of beauty was "the nameless grace/Which waves in every raven tress." The excerpt comes from the poem "She Walks in Beauty."
Whole genes and parts of genes can be extracted from chromosomes, linked to other DNA molecules to form recombinant DNA and introduced into living cells. In a process known as gene cloning, the host cell's biochemical processes are used to make many copies of the inserted gene and the protein it codes for.
The branch of biology dealing with interactions along organisms and between organisms and their environment is called Ecology, I believe.
Cell division is when the cell divides its chromisomes. Replication is when it replicates or makes another dna molocule like it.