Fill in the blanks on the phylogenetic tree (on the facing page) ...

Question

Fill in the blanks on the phylogenetic tree (on the facing page) to show current hypotheses for the origin of multicellular organisms. a. b. c. d. e. f.

Accepted Answer

Hi everyone. Let's look at our next question. It says how did scientists find out that fungi are more closely related to animals than green plants? Well even if we didn't remember off the top of our head how this was found out we can look at our answer choices and kind of logic our way to it and we look at our answer choices. We see that choice A. Is by studying the morphological characteristics. Well again morphological characteristics or this outward appearance function, inner structure and form of things. But if we just say the more falah characteristics of fungi and animals and plants we definitely would lead to the conclusion that fungi must be more like plants. They look more like plants than animals. And so that would not have led scientists to the conclusion that fungi are more closely related to animals. So we can go ahead and eliminate choice A. That's the same case with choice D. By studying the behavioral traits. Um Fun giant plants don't really have much in the way of behavior um compared to animals. So again just looking at behavioral traits would not have led scientists to this conclusion. So we can eliminate Choice B. Choice D. Excuse me. So now we're left with choices B. And C. Choice B. Is by studying the R. RNA genes that would be ribosomes RNA. And Choice C. Is by studying mt DNA genes. The mitochondrial DNA genes. Um Both of these genes are studied to look at um evolutionary relationships comparing sequences for these genes, mitochondrial D. N. A. Is useful. It's only inherited from the mother. Um So since you don't have a combination with another parent, it changes more slowly than much of the somatic D. N. A. Um But it still changes more rapidly then the genes for the R. RNA. These genes change change extremely slowly. So since when we talk about um taxi like fungi and animals and plants and their emergence we're talking about one hundreds of millions of years ago. So studying the R. RNA genes is what led scientists the conclusion that fungi are more closely related to animals than plants. Um mitochondrial DNA, though useful for studying these relationships um and definitely changing more slowly than somatic DNA. Uh is better for studying evolutionary relationships that are more recent than these hundreds of millions of years ago where we had fungi diverging from animals and plants. So we're going to eliminate Choice C. And our answer here, how did scientists find out that fungi are more closely related to animals? And green plants? Is Choice B. By studying the R. RNA genes. See you in the next video

Fill in the blanks on the phylogenetic tree (on the facing page) to show current hypotheses for the origin of multicellular organisms. a. b. c. d. e. f.

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