Chapter 24

Gram-Positive Bacteria

-actinomycetes -streptomces -bacillus anthracis -clostridium botulinum -mycoplasms -bacteria have simpler walls w/ a large amount of peptidoglycan

carbon source

-autotrophs -heterotroph -prokaryotic lifestyle

energy

-electrons are the nrg for cells -chemotrophs -phototrophs -prokaryotic lifestyle

endotoxins

-fragments of outer membrane + cell wall -toxic shock -shock

proteobacteria

-gram-negative bacteria -includes: photoautotrophs, chemoautotrophs, + heterotrophs

spirochetes

-helical heterotrophs -causes Lyme diseases

heterocysts

-in cyanobacteria -photosynthetic cells + nitrogen-fixing cells

chlamydias

-parasites that live within animal cells -causes blindness + mongonococcal urethritis by sexual transmission

exotoxins

-poisons released by some cells -anthrox toxin -botulinum toxin -cholera toxin

key features of prokaryotic biology that allow prokaryotes to divide quickly

-they are small -the reproduce binary fission -they have short generation times

commensation

1 organism benefits while neither harming nor helping the other in any significant way

What are the features of prokaryotes that enable them to adapt so quickly?

They have short generation times. Each time they undergo DNA replication, spontaneous mutations can occur. They can undergo genetic recombination in three ways: conjugation, transformation, and transduction.

F factor

a piece of DNA required for the production of pili

capsule

a polysaccharide or protein layer

transformation

a prokaryotic cell can take up + incorporate foreign DNA from the surrounding environment in a process

symbiosis

an ecological relationship in which 2 species live in close contact: larger host + smaller symbiont

parasitism

an organism called a parasite harms but doesn't kill its host

extremophiles

archae that live in extreme environments

mutualism

both symbiont organisms benefit

autotroph

carbon from CO2

R plasmids

genes for antibiotic resistance are carried in R plasmids

gram-negative bacteria

have less peptidoglycan + an outer membrane that can be toxic

chemotrophs

high nrg e- from inorganic chemicals

phototrophs

light nrg is used for splitting e-from other molecules

extreme halophiles

live in highly saline environments

extreme thermophiles

live in very hot environments

pili

longer than fimbriae + allow prokaryotes to exchange DNA

Prokaryotes lack the nucleus found in eukaryotic cells. As a result, prokaryotic cells do not contain which of the following? A.a nuclear membrane B.DNA C.one or more chromosomes D.all of the above

A.a nuclear membrane

Mycoplasmas are bacteria that lack cell walls. On the basis of this structural feature, which statement concerning mycoplasmas should be true? A. They are gram-negative. B. They are subject to lysis in hypotonic conditions. C. They lack a cell membrane as well. D. They should contain less cellulose than do bacteria that possess cell walls. E. They possess typical prokaryotic flagella.

B. They are subject to lysis in hypotonic conditions.

heterotrophs

C from organic molecules

An organism has a relatively large number of Hox genes in its genome. Which of the following is true of this organism? A. These genes are fundamental, and are expressed in all cells of the organism. B. The organism must have multiple paired appendages along the length of its body. C. The organism has the genetic potential to have a relatively complex anatomy. D. Most of its Hox genes owe their existence to gene fusion events. E. Its Hox genes cooperate to bring about sexual maturity at the proper stage of development.

C. The organism has the genetic potential to have a relatively complex anatomy.

Upon being formed, oceanic islands, such as the Hawaiian Islands, should have what characteristic, leading to which phenomenon? A. mass extinctions, leading to bottleneck effect B. major evolutionary innovations, leading to rafting to nearby continents C. a variety of empty ecological niches, leading to adaptive radiation D. overcrowding, leading to rafting to nearby lands

C. a variety of empty ecological niches, leading to adaptive radiation

The first genes on Earth were probably A. DNA produced by reverse transcriptase from abiotically produced RNA. B. DNA molecules whose information was transcribed to RNA and later translated in polypeptides. C. auto-catalytic (self-replicating) RNA molecules. D. oligopeptides located within protobionts.

C. auto-catalytic (self-replicating) RNA molecules.

Which of the following gets its energy from sunlight and its carbon from ingesting other organisms? A. photoautotroph B. chemoautotroph C. photoheterotroph D. chemoheterotroph

C. photoheterotroph

Which of the following statements best describes most bacteria? A.They are generally harmful. B.They are limited to living in a few habitats. C.They are very common in the environment. D.They are responsible for the "common cold."

C.They are very common in the environment.

Which of the following is not a structure found in prokaryotes? A.ribosome B.endospore C.nucleus D.plasmid

C.nucleus

Which of the following gets its energy from sunlight and its carbon from ingesting other organisms? A.photoautotroph B.chemoautotroph C.photoheterotroph D.chemoheterotroph

C.photoheterotroph

Cyanobacteria that can perform nitrogen fixation... A.use this metabolic pathway to provide themselves with glucose. B.cannot also perform aerobic photosynthesis. C.provide both fixed nitrogen and fixed carbon dioxide to other organisms. D.do so on membranes called thylakoids. E.are part of the community of organisms at deep-sea vents.

C.provide both fixed nitrogen and fixed carbon dioxide to other organisms.

In what type of environment would you find extreme halophiles living? A.ice B.hot springs C.very salty water D.anoxic swamps

C.very salty water

Which features of bacteria can be considered to be defensive structures?

Cell wall: prevents lysis, barrier to some pathogens and chemicals Endospore: resistant structure Capsule: inhibits attack by phagocytes and phage and inhibits dehydration Restriction enzymes: foil phage infections R plasmids: confer protection from certain antibiotics Secretory systems: Can remove toxins from cells

A genetic change that caused a certain homeobox (Hox) gene to be expressed along the tip of a vertebrate limb bud instead of further back made possible the evolution of the tetrapod limb. This type of change is illustrative of A. heterochrony, a change in the timing of developmental events. B. allopolyploidy, an increase in chromosome number. C. paedomorphosis, or retention of ancestral juvenile structures in an adult organism. D. a change in a homeotic developmental gene that altered the spatial organization of body parts. E. allopatric speciation.

D. a change in a homeotic developmental gene that altered the spatial organization of body parts.

What is true of archaeans? A.They are the cause of many human diseases. B.Structurally, they represent an intermediate form between bacteria cells and eukaryotic cells. C.They are extremophiles. D.They have undergone horizontal gene transfer with bacteria and with eukaryotes. E.They include Earth's first aerobic photosynthesizers.

D.They have undergone horizontal gene transfer with bacteria and with eukaryotes.

Which of the following have a thicker, simpler cell wall? A.bacillus B.gram-negative bacteria C.coccus D.gram-positive bacteria

D.gram-positive bacteria

cyanobacteria

photoautotrophs that generate O2

plasmids

smaller rings of DNA

shock

sudden drop in bp

taxis

the ability to move toward or away from a stimulus

chemotaxis

the movement toward or away from a chemical stimulus

conjugation

the process where genetic material is transferred between prokaryotic cells

bioremediation

the use of organisms to remove pollutants from the environment

A prokaryote that obtains carbon molecules (food) from dead organisms and energy from light; A. photoheterotroph B. heterotroph C. photoautotroph D. chemoautotroph

A. photoheterotroph

Prokaryotes lack the nucleus found in eukaryotic cells. As a result, prokaryotic cells do not contain which of the following? A. nuclear envelope B. DNA C. one or more chromosomes D. all of the above

A. nuclear envelope

Prokaryotic ribosomes differ from those present in eukaryotic cytosol. Because of this, which of the following is correct? A. Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host. B. Eukaryotes did not evolve from prokaryotes. C. Translation can occur at the same time as transcription in eukaryotes but not in prokaryotes. D. Some antibiotics can block the synthesis of peptidoglycan in the walls of bacteria.

A. Some antibiotics can block protein synthesis in bacteria without effects in the eukaryotic host.

Plantlike photosynthesis that releases O2 occurs in A. cyanobacteria. B. chlamydias. C. archaea. D. actinomycetes. E. chemoautotrophic bacteria.

A. cyanobacteria.

F plasmid

F+ function as DNA donors during conjugation