LSU BIOL 1202 (HRINCEVICH) CH. 26 HW

The horizontal line indicating a branch on a phylogenetic tree represents ancestral forms of the named taxon, thereby illustrating the ____________.

evolutionary lineage

Which observation supports the position of eukaryotes at the convergence of the "ring of life"? A. Only eukaryotes perform mitosis. B. Introns are rare in both bacteria and archaeans. C. Circular chromosomes are present in both bacteria and archaeans. D. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria. E. Eukaryotes and archaeans both lack peptidoglycan in their cell walls.

D. The nuclear genome of eukaryotes contains genes from archaeans and from bacteria.

This is one possible phylogenetic tree representing the relationships between some members of phylum Arthropoda. Use this phylogenetic tree and your knowledge of cladistics to determine the relationships between these species. Rank the species from most closely related to horseflies to most distantly related to horseflies. If two species are equally close in their relatedness to horseflies, overlap them.

Most CLOSELY related to horseflies 1: flea 2: katydid, human body louse 3: dragonfly, mayfly 4: silverfish Most DISTANTLY related to horseflies

Imagine that you are studying alien life-forms discovered on a distant planet. While geneticists are working out the genetic code of these organisms, you are asked to construct a phylogenetic tree based on four morphological features, or characters: presence or absence of a spring tail, presence or absence of a grasping hand, presence or absence of a second tail, and number of eyes. The organisms have been divided into five groups based on these characters. If we assume the alien with a tail stalk is an outgroup, what is the most likely phylogenetic tree based on these shared derived characters? When did these characters appear during the aliens' evolutionary history? Drag the aliens and shared derived characters to their appropriate locations on this phylogenetic tree.

a. spring tail b. fourth eye c. second tail d. grasping hand e. green alien with three eyes f. yellow alien with three eyes g. blue alien with four eyes h. purple alien with four eyes i. green alien with four eyes

The geneticists studying the alien organisms have deciphered their genetic code. For familiarity, they have used A, C, G, and T to indicate the bases in this code. A comparable genetic sequence in each alien has been identified in the genes that code for eye growth. This genetic sequence has allowed the aliens to be divided into six groups, with the single-tail, three-eye group split in half. The geneticists also studied several outgroup species (not shown) to compile a likely ancestral DNA sequence. From this information, they have constructed four possible phylogenetic trees. Based on this genetic information, which phylogenetic tree is most parsimonious? Select the most parsimonious tree. If there is a tie, select both trees. a. phylogenetic tree I b. phylogenetic tree II c. phylogenetic tree III d. phylogenetic tree IV

c. phylogenetic tree III

Turtles are not shown on this tree. Turtles are evolutionarily more closely related to lizards than they are to frogs. Select the phylogenetic tree that best represents the position of turtles relative to the other taxa shown.

https://media.cheggcdn.com/coop/7ca/7ca4bca1-5c9e-4d3f-814f-fc3612161ce7/1591340872148_turtlemonophylaticgroup.png

A study published in 2000 sequenced part of the mitochondrial cytochrome b gene from 61 brown bears from two sites in Alaska. One population of brown bears lives on the coastal mainland of Alaska, while a separate population lives on the ABC islands in southeastern Alaska. Mainland and ABC brown bears differ by 11 fixed nucleotide substitutions in the cytochrome b gene. This suggests that the two brown bear populations represent genetically unique clades. The researchers compared the cytochrome b sequences of the two clades of Alaskan brown bears to those of 55 polar bears. The analysis showed that polar bears and ABC brown bears differ at only three nucleotides in this gene, whereas polar bears and mainland brown bears had more differences. Based on the results of the 2000 study, how should the portion of the tree extending from branch point 7 be altered?

--------mainland brown 7----- _____ ABC brown bear |_____ Polar bear

The branching pattern of a phylogenetic tree indicates whether taxa are closely or distantly related relative to other taxa in the tree. Use this phylogenetic tree to determine whether each statement is true or false. 1. Fishes and chimps have no common ancestors. 2. Frogs and humans are more distantly related than are lizards and humans. 3. The taxon that shares the most recent common ancestor with frogs is fishes. 4. In this tree, lizards are the sister taxon of the lineage that includes humans and chimps.

1. False 2. True 3. False 4. True

Use the same diagram to determine whether each statement is true or false. 1. Branch point 1 represents the common ancestor of Taxa A-F. 2. Taxa D and E arose from a common ancestor and are sister taxa. 3. Branch point 2 is the common ancestor shared uniquely by Taxa A, B, and C. 4. Rotating the tree at branch point 2 would change the relationship between Taxa D and A.

1. True 2. True 3. False 4. False

Based on the character table in Part B, which of the following statements about shared derived characters in plants is correct? A. Seeds are a shared derived character of pines, cherries, and peas. B. Flowers and fruit are shared derived characters of ferns, pines, peas, and cherries. C. Cones are a shared derived character of pines, peas, and cherries. D. The vascular system is a shared derived character of mosses and ferns.

A. Seeds are a shared derived character of pines, cherries, and peas.

Based on this tree, select the correct statement. A. Taxon A is the sister taxon of the lineage that includes Taxa B and C. B. Taxon F is the common ancestor to all other taxa shown. C. Branch point 2 indicates a common ancestor for Taxa A, D, and E, but not B or C. D. The sequence of evolution represented on the tree leads to Taxon A, shown at the top of the tree.

A. Taxon A is the sister taxon of the lineage that includes Taxa B and C.

Which branch point represents the most recent common ancestor of all bears? A. branch point 1 B. branch point 2 C. branch point 3 D. The most recent common ancestor to all living bears is not shown in this tree.

A. branch point 1

Which species is the basal taxon in this tree? A. the giant panda B. the spectacled bear C. the polar bear D. the sloth bear

A. the giant panda

Look at this character table. Rattlesnakes (like turtles) are reptiles, yet they do not have four limbs. In fact, they have no apparent limbs. What does this suggest? A. Of the species in the table, rattlesnakes are most closely related to lampreys. B. The presence or absence of four limbs, on its own, could be misleading when considering the evolutionary relationships of rattlesnakes. C. Rattlesnakes are more closely related to bass than they are to frogs, turtles, and leopards. D. The presence or absence of four limbs is not a useful character for studying evolutionary relationships among vertebrates.

B. The presence or absence of four limbs, on its own, could be misleading when considering the evolutionary relationships of rattlesnakes.

Which branch point represents the most recent common ancestor of the sloth bear and the spectacled bear? A. branch point 1 B. branch point 2 C. branch point 3 D. The sloth bear and the spectacled bear do not share a common ancestor.

B. branch point 2

According to this tree, is the sun bear more closely related to the sloth bear or the polar bear? A. the sloth bear B. the polar bear C. The sloth bear and the polar bear are equally distant relatives of the sun bear.

B. the polar bear

Suppose that a phylogenetic tree were constructed using the data shown in this table. Mosses represent the outgroup. What would the resulting tree suggest? A. Mosses and peas are each other's closest relatives. B. Ferns and peas are each other's closest relatives. C. Cherries and peas are each other's closest relatives. D. Cherries and pines are each other's closest relatives.

C. Cherries and peas are each other's closest relatives.

The tree includes the most recent common ancestor of all living species of bears (branch point 1). What does this tell you about this phylogenetic tree? A. The Ursidae family is a polyphyletic group. B. The Ursidae family is a paraphyletic group. C. This phylogenetic tree is rooted. D. This phylogenetic tree contains homoplasies.

C. This phylogenetic tree is rooted.

Based on the revised branch of the tree, what kind of group do brown bears plus ancestral species 7 represent? A. a monophyletic group B. a polyphyletic group C. a paraphyletic group

C. a paraphyletic group

Which branch point represents the most recent common ancestor of the Asian black bear and the brown bear? A. branch point 2 B. branch point 3 C. branch point 4 D. branch point 5

C. branch point 4

Animals that possess homologous structures probably _____. A. are the result of similar environmental pressures in different evolutionary lineages B. are not related C. evolved from the same ancestor D. have increased genetic diversity E. are the result of convergent evolution

C. evolved from the same ancestor

Which of the following groups of species is a monophyletic group, or clade? A. sun bear, sloth bear, spectacled bear B. brown bear, polar bear, ancestral species 4, ancestral species 7 C. sun bear, Asian black bear, American black bear, ancestral species 5, ancestral species 6 D. all species of living bears

C. sun bear, Asian black bear, American black bear, ancestral species 5, ancestral species 6

Identify the sister taxon to the polar bear. A. the Asian black bear B. the American black bear C. the brown bear D. the ancestor represented by branch point 7

C. the brown bear

The point at which two or more lineages diverge from their common ancestor is called a(n) ____________or node.

branch point

Molecular clocks are based on the idea that _____. a. mutations occur once every generation b. molecules resonate at a certain frequency that can be measured c. advantageous mutations arise at a constant rate d. on average neutral mutations arise at a constant rate e. directional selection occurs at a constant rate

d. on average neutral mutations arise at a constant rate

Why do researchers use rRNA in investigations of relationships between taxa that diverged hundreds of millions of years ago? a. rRNA is never the nucleic acid chosen for comparisons. b. rRNA cannot mutate. c. rRNA is traditionally the nucleic acid chosen for recent comparisons. d. rRNA changes at different rates in different taxa. e. DNA coding for rRNA changes relatively slowly.

e. DNA coding for rRNA changes relatively slowly.

__________are groups of organisms that share a unique common ancestor not shared by any other groups.

sister taxa

Each branch tip on a phylogenetic tree represents a specific group of organisms known as a(n) ________.

taxon