Question

a geneticist examines part of a gene sequence in four different but related species. for each species, the bases in the sequence are indicated in the chart below. she then determines that the common ancestor of these four species has a dna strand of acctaggtgagc. based on this data, which species is most closely related to the common ancestor? 1 2 3 4

Explanation:

To determine which species is most closely related to the common ancestor, we compare the DNA strand of each species with the DNA strand of the common ancestor (ACCTAGGTGAGC). Species 2 has the DNA strand ACCTAGGTGTGC. When we compare it with the ancestor's strand, we can see that it has fewer differences compared to the other species. For example, species 1 ( AACA AGGTGTGC) has more differences at the beginning (AACA vs ACCT). Species 3 (ACCA AGGTGTCC) has differences in the middle (AA vs AG) and at the end (CC vs GC). Species 4 (ACCA AGT TGTCC) has even more differences.

Answer:

B. 2