Question

select the statement(s) that are correct about the diagram.
b is more closely related to a than g.
there are more differences between the organisms when they have a less recent common ancestor.
all organisms share a common ancestor, represented by the letter a.
h and i are closely related to a.
f is not as closely related to b as b is to e.
tree diagram with labels: species (h, i, c), genus (f), family, order (g), class (d, e), phylum (b), kingdom (a)

Explanation:

• For "B is more closely related to A than G":
• In a phylogenetic tree, the closer the common ancestor (in terms of number of branching points), the more closely related. B shares a more recent common ancestor (A) with A than G does (A is also the common ancestor for G but with more branching in between for G compared to B).
• For "There are more differences between the organisms when they have a less recent common ancestor":
• Over time (more branching, less recent common ancestor), more genetic and phenotypic changes (differences) accumulate.
• For "All organisms share a common ancestor, represented by the letter A":
• In the given diagram, A is at the base (kingdom level), and all other taxa (B - I) branch from it, so A is the common ancestor.
• For "H and I are closely related to A":
• H and I are at the species level, and while A is their ultimate ancestor (kingdom level), they are not "closely" related in the sense of recent common ancestry compared to, say, B and A. There are many taxonomic levels (phylum, class, order, family, genus) between A (kingdom) and H/I (species).
• For "F is not as closely related to B as B is to E":
• B and E share a more recent common ancestor (at the phylum level) than B and F (F is at the genus level, and the common ancestor for B and F is A, with more branching in between for F compared to E).

Answer:

• B is more closely related to A than G.
• There are more differences between the organisms when they have a less recent common ancestor.
• All organisms share a common ancestor, represented by the letter A.
• F is not as closely related to B as B is to E.