Concept explainers
Using the phylogenetic tree in Figure 17.1 as a guide, discuss what indicates that bacteriorhodopsin may have been a late evolutionary invention and that anaerobic respiration with S0 as electron acceptor might have been an early evolutionary invention.
Figure 17.1 Schematic representation of the phylogeny of the major taxonomic orders within the domain Archaea. Each of the five archaeal phyla and their major orders are indicated in a different color.
The term phylogeny is defined as the history of evolution or descent of pattern of a group of organisms from their ancestors. A branching diagram known as cladogram or a phylogenetic tree conceptually represents the phylogeny. The branch that deals with systematics inferring phylogeny are known as phylogenetic systematics or cladistics. The primary goal of phylogenetic systematics is to pattern the descent of a group of organisms. The phylogenetic systematics have the main goal to determine the life history of descent. The phylogenetic systematics are represented as branching pattern and can be determined through the analysis of characters of living or fossil organisms according to phylogenetic principles and methodology.
Explanation of Solution
In the figure, Archaea shows extensive phenotypic diversity. Archaea mainly constitutes of chemoorganotrophic or chemolithotrophic organisms. With respect to evolutionary aspect, Archaea is divided into two main phyla: Crenarchaeota and Euryarchaeota. Crenarchaeota includes mainly hyperthermophiles. Euryarchaeota is physiologically diverse group and many of the organisms are found in extreme environmental conditions. Methanogens and extremely halophilic organisms are included in this phylum. This phylum also includes hyperthermophiles. In Eurychaeota phylum it is observed that Halobacterium which consists bacteriorhodopsin appears very late on the phylogenetic tree justifying late invention of bacteriorhodopsin. Bacteriorhodopsin helps in ATP production in Halobacterium salinarum.
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Chapter 17 Solutions
Brock Biology Of Microorganisms 15th.ed. I.e.
- The genus Ferroplasma consists of a few species of acid-loving archaea. One species, F. acidarmanus, was discovered to be the main component of slime streamers (a type of biofilm) deep inside an abandoned California copper mine (Figure 4.11A). F. acidarmanus cells use an ancient energy-harvesting pathway that combines oxygen with ironsulfur compounds in minerals such as pyrite. This reaction dissolves the minerals, so groundwater that seeps into the mine ends up with extremely high concentrations of metal ions such as copper, zinc, cadmium, and arsenic. The reaction also produces sulfuric acid, which lowers the pH of the water around the cells to zero. Despite living in an environment with a composition similar to hot battery acid, F. acidarmanus cells maintain their internal pH at a cozy 5.0. Thus, researchers investigating Ferroplasma metabolic enzymes were surprised to discover that most of the cells enzymes function best at very low pH (Figure 4.11B). A. Deep inside one of the most toxic sites in the United States: Iron Mountain Mine, in California. The water in this stream, which is about 1 meter (3 feet) wide in this photo, is hot (around 40C, or 104F), heavily laden with arsenic and other toxic metals, and has a pH of zero. Slime streamers growing in it are a biofilm dominated by a species of archaea, Ferroplasma acidarmanus. B. pH profiles of four enzymes isolated from F. acidarmus. Researchers had expected these enzymes to function best at the cells cytoplasmic pH (5.0). What does the dashed line signify?arrow_forward. Which of the following prokaryotic kingdoms is characterized by the absence of a nucleus, the absence of histone proteins, the presence of fatty acids ester-linked to glycerol in their G-3-P cell membrane, and the presence of enzymes for constructing a peptidoglycan cell wall? kingdom Archaeobacteria kingdom Animalia kingdom Fungi kingdom Plantae kingdom Eubacteriaarrow_forwardThe TATA-binding protein (TBP) is thought to be necessary for transcription in all eukaryotic cell nuclei. Studies show that archaea, but not bacteria,have a protein structurally and functionally similar to TBP. What does this similarity suggest regarding the evolution of archaea, bacteria, and eukaryotes? How might knowledge of this similarity affect how systematists classify these organisms?arrow_forward
- This chapter shows a phylogenetic tree for the three domains of life, which is based on DNA sequence data for rRNA and other genes. Which of the following answers concerning the phylogenetic relationships found within this tree is incorrect? View Available Hint(s)for Part A Euryarcheotes are found in the Archaea Diatoms, Tubulinids, and Euglenozoans belong to the domain Eukarya Forams, Fungi, and Chlamydias belong to the domain Eukarya. Spirochetes belong to the domain Bacteria Ciliates, Red Algae, and Plants belong to the domain Eukarya.arrow_forwardGive explanation Which of the following statements is TRUE based on the phylogenetic tree shown? a) Bacteria and archaea are equally related to to eukarya b) Plants and ciliates are more closely related than plants and animals c) Green sulfur bacterial are more closely related to archaea than the Thermotogales d) Methanosarcina and Haloarchaea are equally related to Methanococcus e) Flavobacteria are the last common ancestor between bacteria and eukaryaarrow_forwardWhich of the following statements about eukaryotes is correct? - Eukaryotes are life forms that possess a nucleus in the cells. - Some cellular features, such as endoplasmic reticulum, is uniquely eukaryotic and is not shared with either bacteria or archaea. - It has been hypothesized that the first eukaryotic cell is a chimera between a bacterium and an archaeon. - During phylogenetic reconstruction, it is often found that eukaryotic genes that are responsible for information processing are more closely related to corresponding archaeal genes than to bacterial genes. - All of the abovearrow_forward
- Which of the following prokaryotes has a relatively large surface-to-volume ratio for rapid gas exchange, despite having one of the largest cytoplasmic volumes of any known eubacterial cell? the archaeobacterium Halobacterium halobium the archaeobacterium Nanoarchaeum equitans the eubacterium Rhodopseudomonas viridis the eubacterium Epulopiscium fishelsoni the eubacterium Escherichia coliarrow_forward. Single-celled organisms with a true nucleus, ester-linked fatty acids in their G-3-P cell membranes, and histones, but no collagen, and no cell walls composed of either chitin or cellulose, must be: members of kingdom Archaeobacteria members of kingdom Protista members of kingdom Eubacteria members of kingdom Fungi members of kingdom Animaliaarrow_forwardThere are three main ways that bacteria and archaea are essential to eukaryotic life. Explain the three different ways and give at least one example of each.arrow_forward
- Consider the fact that the use of 16S rRNA sequencing as a taxonomic and phylogenetic tool has resulted in tripling the number of bacterial phyla. Why has the advent of this genetic technique expanded the currently accepted number of microbial phyla?arrow_forward. The endosymbiotic hypothesis for the origin of mitochondria from gram-negative prokaryotes is supported by all of the following lines of evidence except: A. the presence of enzymes for the Krebs cycle, electron transport, and oxidative phosphorylation the presence of mRNA, tRNA, and rRNA similar to that of the a-proteobacteria the presence of 80s ribosomes, consisting of 40s and 60s ribosomal subunits the presence of circular DNA resembling that of aerobic proteobacteria their use of binary fission rather than mitosis during cell divisionarrow_forwardWhich of the following statements is correct? Please select all that apply. Select one or more: a. Parasitism between bacteria and archaea caused complex interactions that eventually gave rise to eukarya. b. While bacteria are prokaryotes, archaea are neither prokaryotic, nor eukaryotic but classified as a 3rd cell type. c. Prokaryotes are classified further based on whether they are unicellular or multicellular organisms. d. The molecular biologies of archaea and eukarya show a greater proportion of similarities than those of eukarya and bacteria. e. Prokaryotes could not make photosynthesis until chloroplast endosymbiosis evolution. f. The last universal common ancestor most likely had a primitive prokaryotic cell organization. g. Endosymbiosis of chloroplast precedes that of mitochondria.arrow_forward
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning