To estimate the relative abundance of the major phyla, calculate how many named species of arthropods, mollusks, and nematode worms exist per named species of chordate (the phylum containing vertebrates, including humans; see Table 30.1). Do you think these calculations are likely to be underestimates or overestimates? Why?

Video transcript

Hello everyone and welcome to today's video. So today we have that the following four assertions about coordinates. And we're given these four statements that we need to go over and identify the correct one regarding the phylum coordinates. So now that we know this, let me just help you recall the five main scene up more fees that all coordinates share in their adulthood stage as this is going to help us solve the problem. So all coordinates have not occurred. They have a dorsal hollow nerve cord, they have an end of style or a thyroid differentials lead and a pose in hotel at some stage of their development. So now that we know this, let's quickly jump over answer choices so that we can begin solving the problem. Beginning by statement. P humans are classified as vertebrate coordinates. Remember that as humans we have a backbone or a spinal column which classifies us as vertebrates. So this is a correct statement and we're not going to cancel it out. Then we have statement Q. The dorsal hollow nerve cord is present in all coordinates at some stage of their development. I want you to look at this statement that we had here. This dorsal hollow nerve cord is one of the five Singapore more feet of cord, eight. So we're not going to cancel this out either because it is a correct statement. Then we have statement or or coordinates but says a brain case. This is a structure incorporates However, coordinates such as invertebrates will not possess these brain brain case so we're going to cancel it out because it says that all coordinates should possess it, which is an incorrect statement. Then we have statement S nematodes are invertebrate coordinates. Remember that nematode is a phylum that includes, for example roundworms, they're not part of core dates, so this is actually an incorrect statement, and we're going to cancel it out as well. And this leaves us with statements P and Q being the only correct ones which is going to be represented by answer choice C. But it's the end of the video, and I really hope this helped you.