Question

10.5.2 test (cst): computer - based unit test

a. dogs are the outgroup.
b. sponges evolved after amoeba.
c. lizards use placental birth.
d. dogs evolved before koalas.

Explanation:

1. Analyze the phylogenetic tree: In a phylogenetic tree, organisms closer to the common - ancestor branch earlier.
2. For option A: There is no indication that dogs are the out - group from the given tree.
3. For option B: Sponges and amoeba are not shown in the tree, so this cannot be determined.
4. For option C: Lizards are not placental mammals and do not use placental birth.
5. For option D: Looking at the tree, the branch for dogs is closer to the common ancestor than the branch for koalas, indicating that dogs evolved before koalas.

Answer:

D. Dogs evolved before koalas.