There is some evidence that pharyngeal slits occur in certain spe...

Question

There is some evidence that pharyngeal slits occur in certain species of echinoderms that appear early in the fossil record. If confirmed, what do these data suggest?
a. Echinoderms are chordates.
b. Pharyngeal slits were present in the earliest echinoderms and lost later.
c. Some lineages of echinoderms are more closely related to chordates than others.
d. Pharyngeal slits should not be used as a trait in phylogenetic analysis.

Accepted Answer

Hello everyone and welcome to today's video. So what is true about for angels? Let's before we jump into a problem. I really want to help you recall what these four angels let's are in order to better solve this. But first of all they're embryonic structures and they're used in respiration and feeding. Now that we know this, let's jump into the answer choices beginning by answer choice. A. They are present in all animals. Remember that there are animals such as sponges that don't really display these differentials lips. So we're going to cancel this out. Then we have c they evolved into a fence and fish. Well, these four angels lips are embryonic structures so they're bound to develop into something, however they do not develop into the fence of fish. They develop into the gills because of their function in respiration. This is something that they have in common. So we're going to cancel this out because it is incorrect. Then we have deep their present throughout the life of court dates. We already said that these are embryonic structures so they're only present during embryonic development because of this. This is an incorrect answer choice and we're going to cancel this out. And finally we have these are unique characteristics of court dates. Well, court dates are actually the only group of organisms that display these fringes lips. So this is a correct answer choice and we're going to highlight it as a final answer to our question. I really hope this helped you and I really hope to see you on the next one

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