EXAM 2 Chapter 29 MasteringBiology

Require energy from at least one organic nutrient and use light as an energy source.

photoheterotrophs

Require energy from either inorganic sources or from at least one organic nutrient and use light as an energy source are also known as __________.

phototrophs

What organisms are most numerous on Earth? insects plants eukaryotes prokaryotes archaea

prokaryotes

The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

proteobacteria Note: Proteus vulgaris is classified with proteobacteria.

Spiral-shaped bacteria are likely to be placed with _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

spirochetes Note: The name of these organisms provides the answer to the question.

The Gram stain, commonly used to classify a bacterial isolate into one of two groups, is based upon the characteristics of which of the following structures? the flagella the cell wall the genetic material the ribosomes

the cell wall Note: Gram positive cells have a thick cell wall with a lot of peptidoglycan, while Gram negative cells have only a thin layer of peptidoglycan sandwiched between two phospholipid bilayers.

What is distinctive about the chlorophylls found in different photosynthetic bacteria? their absorption spectra their role in acquiring energy their role in carbon fixation their membranes

their absorption spectra

_____(1)_____ is a technique for classifying _____(2)_____ based on differences in the structure of their _____(3)_____. Gram-negative bacteria and gram-positive bacteria both have a _____(4)_____ surrounded by a cell wall that contains _____(5)_____. However, the cell wall of _____(6)_____ is composed of a thin layer of peptidoglycan and an outer membrane, whereas the cell wall of _____(7)_____ is composed of a thick layer of peptidoglycan. _____(8)_____ appear red or pink because the alcohol rinse washes away the crystal violet dye. _____(9)_____ appear purple because the alcohol rinse does not wash away the crystal violet dye.

(1) Gram-staining (2) bacteria (3) cell wall (4) plasma membrane (5) peptidoglycan (6) gram-negative bacteria (7) gram-positive bacteria (8) gram-negative bacteria (9) gram-positive bacteria

Some bacteria obtain energy from light {_____(1)_____}, whereas other bacteria obtain energy from chemicals {_____(2)_____}. _____(3)_____ (literally "self-feeders") require only an inorganic substance, such as carbon dioxide, as their carbon source; _____(4)_____ (literally "other-feeders") require at least one organic nutrient as their carbon source.

(1) phototrophs (2) chemotrophs (3) autotrophs (4) heterotrophs

Which of the following statements about phylogenetic trees is true? A paraphyletic group consists of a common ancestor and some of its descendants. A paraphyletic group has not experienced lateral gene transfer. A monophyletic group consists of a common ancestor and some of its descendants. A paraphyletic group consists of an ancestral population and all of its descendants.

A paraphyletic group consists of a common ancestor and some of its descendants. Note: This statement is true; the common characteristics of a paraphyletic group may have arisen from lateral gene transfer to some, but not all, lineages.

Which of the following conditions can be varied in an enrichment culture to isolate bacteria that prefer a specific set of conditions? temperature food source pH All of the above are correct.

All of the above are correct. Note: Many different conditions can be varied in an enrichment culture to match the organism's preferred environment.

Prokaryotes are classified as belonging to two different domains. What are the domains? Bacteria and Protista Bacteria and Archaea Bacteria and Eukarya Eukarya and Monera Archaea and Monera

Bacteria and Archaea

Gram-positive bacteria or gram negative bacteria? Have a plasma membrane.

Both gram-positive and gram-negative bacteria

True or False. All the pathogenic forms come from one definite lineage in the domain Bacteria.

False

What distinguishes bacteria from archaea? Only bacteria contain a circular chromosome. Only bacteria have peptidoglycan in their cell walls. Only bacteria are unicellular. Only bacteria lack a membrane-bound nucleus to house the genetic material.

Only bacteria have peptidoglycan in their cell walls. Note: Bacteria and archaea share many similarities, but only bacteria have peptidoglycan-containing cell walls.

When using Koch's postulates, which of the following is an essential requirement for the suspected pathogen? It can be cultured on an agar plate. It can reproduce sexually within the host. It is present in all organisms with the disease. It is pathogenic on a wide variety of organisms.

It is present in all organisms with the disease.

What is lateral gene transfer? Inheritance of a gene through mitosis Inheritance of a gene from a parent Physical transfer of a gene from a species in one lineage to a species in another lineage. Inheritance of a gene through meiosis

Physical transfer of a gene from a species in one lineage to a species in another lineage. Note: Lateral gene transfer is the physical transfer of a gene between distantly related lineages.

What characteristics were used to classify organisms before Woese's tree of life analysis? Composition of the cell wall Differences in ribosomal RNA sequences Number of cells in the organism Presence of a membrane-bound nucleus

Presence of a membrane-bound nucleus Note: Before the tree of life analysis, organisms were classified as prokaryotes if they lacked a membrane-bound nucleus or eukaryotes if they possessed a membrane-bound nucleus.

Which group was not described in Woese's tree of life analysis? Archaea Bacteria Eukarya Prokarya

Prokarya Note: Prokarya was not one of the groups described in Woese's tree of life analysis.

Which molecule did Carl Woese study to produce his tree of life? Ribosomal RNA DNA Messenger RNA Ribosome

Ribosomal RNA Note: Ribosomal RNA was the molecule used to produce Woese's phylogeny because it evolves slowly and is critical to the function of the ribosome, which serves the same function in all three domains in the tree of life.

Members of which bacterial phylum share a unique morphology? Proteobacteria Spirochaetes Euryarchaeota Cyanobacteria

Spirochaetes Note: Spirochaetes all have a unique corkscrew shape.

Which is true of archaea? They are composed of two major lineages. They contain many documented human pathogens. They have unique ether-linked lipids in their plasma membranes. They are the only prokaryotic organisms.

They have unique ether-linked lipids in their plasma membranes. Note: This is one of the distinguishing features of archaea. Bacteria and eukarya have ester linkages in their phospholipids.

True or false? Data showing that the Bacteria were the first lineage to diverge from the common ancestor of all living organisms suggest that the Archaea and Eukarya are more closely related to each other than they are to the Bacteria.

True

Require energy only from inorganic sources.

autotrophs

Organisms that synthesize their own C-C molecules from single-carbon starting materials are named _____, while those that absorb preformed C-C compounds are _____. autotrophs; chemoorganotrophs chemoorganotrophs; heterotrophs phototrophs; chemotrophs autotrophs; heterotrophs

autotrophs; heterotrophs Note: Autotrophs are "self-feeders," while heterotrophs are "other-feeders."

Which of the following groups of organisms is among the most abundant on Earth? protozoa primates insects bacteria

bacteria Note: In terms of cell numbers, bacteria far surpass any of the other organisms listed.

Require energy only from inorganic sources and use chemicals as an energy source.

chemoautotrophs

Require energy from at least one organic nutrient and use chemicals as an energy source.

chemoheterotrophs

Require energy from either inorganic sources or from at least one organic nutrient and use chemicals as an energy source are also known as __________.

chemotrophs

Organisms that can cause nongonococcal urethritis are classified with _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

chlamydias Note: Chlamydia trachomatis causes nongonococcal urethritis.

The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

cyanobacteria Note: Cyanobacteria are aerobic photosynthesizers.

The prokaryotic cells that built stromatolites are classified as _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

cyanobacteria Note: Cyanobacteria built stromatolites.

Robert Koch is best known for which of the following contributions? discovery of bacteria establishing a link between bacteria and disease discovering the first antibiotic put into clinical use identifying distinctions between bacteria and archaea

establishing a link between bacteria and disease Note: Koch proposed four criteria that needed to be met for a specific microbe to be identified as the causative agent of a specific disease. Koch first fulfilled his criteria with the bacterium responsible for anthrax.

What do some photosynthetic bacteria use as a source of electrons instead of water? organic compounds (e.g., CH3COO− ) oxygen (O2) ferric ion (Fe3+) ferrous ion (Fe2+)

ferrous ion (Fe2+)

Gram-positive bacteria or gram negative bacteria? Alcohol rinse easily removes crystal violet.

gram-negative bacteria

Gram-positive bacteria or gram negative bacteria? Appear pink after gram-staining.

gram-negative bacteria

Gram-positive bacteria or gram negative bacteria? Have a thin peptidoglycan layer.

gram-negative bacteria

Gram-positive bacteria or gram negative bacteria? Have an outer membrane as part of their cell wall structure.

gram-negative bacteria

Gram-positive bacteria or gram negative bacteria? Alcohol rinse does not remove crystal violet.

gram-positive bacteria

Gram-positive bacteria or gram negative bacteria? Appear purple after gram staining.

gram-positive bacteria

Gram-positive bacteria or gram negative bacteria? Have a thick peptidoglycan layer.

gram-positive bacteria

Streptococcus pyogenes is classified with _____. proteobacteria chlamydias spirochetes gram-positive bacteria cyanobacteria

gram-positive bacteria Note: S. pyogenes attracts the violet Gram stain.

Require energy from at least one organic nutrient.

heterotroph

Cyanobacteria are thought to be the first organisms to evolve ____. aerobic respiration chemolithotrophy oxygenic photosynthesis fermentation

oxygenic photosynthesis Note: Cyanobacteria use light energy to split or oxidize water, with oxygen gas as a by-product. The electrons are passed through an electron transport chain and used to make NADPH and ATP.

Require energy only from inorganic sources and use light as an energy source.

photoautotrophs