For a homology search program such as BLAST, which one of the following best describes the scoring pattern?
1
identical residue = 10 pts, conservative substitution = 5 pts, gap = 0 pts
2
identical residue = 10 pts, conservative substitution = 1 to 9 pts, gap = -3 pts
3
identical residue = 10 pts, conservative substitution = 1 to 9 pts, gap = 0 pts
4
identical residue = 10 pts, conservative substitution = 10 pts, gap = -3 pts