A bandicoot, sea lion and a zebra have similarities and differences in their body structures. What does this info about these structures tell you about the ancestors of these species?

First off, the info tells me that bandicoots, sea lions, and zebras could have all shared a common ancestor at one point in time and then developed differences to be better suited to their respective environments. Further, the similarities in their body structures cannot be attributed to convergent evolution (evolution that produces analogous structures) because the three organisms grow in very different environments; thus it had to have come from homology (common ancestry). Having said that, this tells us that the ancestors most likely had the trait of whatever is shared amongst the body structures of bandicoots, sea lions, and zebras, as this was the trait they passed on. Hope this is helpful :)

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation: