EXAM #1 Bio203
Which of the following does not describe interactions of mixed microbial communities?
Conditions in mixed microbial associations are readily reproduced in the laboratory.
Molecular techniques such as ______ have allowed scientists to determine the phylogeny of microorganisms.
DNA sequencing
Why are sequences of ribosomal RNA so useful in microbial classification and identification?
ID w/o needing to culture
The cytoplasmic membrane lipids of members of the domain are composed of hydrocarbons (not fatty acids) linked to glycerol by ether linkage.
archaea
Which of the following is a difference between archaea and bacteria?
bacteria had peptidoglycan, archaea doesn't
When bacteria or archaea are grown on agar plates or in tubes or flasks of broth, these closed systems are a ___ culture. By contrast, cells can also be grown in an open system, or a continuous culture.
batch
Scientific names are assigned according to the _______ system of nomenclature developed by ______.
binomial, Carl Linnaeus
Peptidoglycan is found in the ______.
cell wall
The bacterial is typically a single, circular, double-stranded DNA molecule that contains all of the essential genetic information required by a cell.
chromosome
Bacteria growing in a natural environment experience ______.
dynamic and complex conditions
Life is divided into three domains. What are they?
eukarya, bacteria, archaea
Which of the following describes how penicillin affects peptidoglycan?
interferes with synthesis
Place the five stages of a growth curve in the correct order, starting from the beginning
lag, log, stationary, death, prolonged decline
Technically speaking, viruses are not microorganisms because they are not ______.
made of cells
Endospores ______.
may germinate to produce vegetative cells, which can then multiply. are very resistant to damaging conditions, including high heat, toxic chemicals, and UV light. are common in soil, and can therefore be found nearly anywhere.
_____ is the most thoroughly studied of a group of antibiotics that prevent the cross-linking of adjacent glycan chains in peptidoglycan.
penicillin
Most bacteria have rigid cell walls that contain a unique compound called
peptidoglycan
The electron transport chain of bacteria creates an electrochemical gradient across the cytoplasmic membrane. Inherent in that gradient is a form of energy called ___ ____force, which cells use to make the energy currency called ______.
proton motive, ATP
Which of the following is considered the most reliable indicator of evolutionary relatedness in prokaryotes?
rRNA sequence
Although archaea and bacteria differ in a number of important characteristics, it was ultimately significant differences in their _______ that provided the basis for separating the two groups of prokaryotes into different domains.
rRNA sequences
The cytoplasmic membrane is a(n) ____-permeable barrier of the cell.
semi
A typical bacterium possesses ______.
single, circular, chromosome
The 16S rRNA molecule is part of the _______ subunit of the prokaryotic ribosome, and is equivalent to the ______ rRNA of eukaryotes.
small, 18S
For facilitated diffusion to occur, the cell requires _______.
transporter proteins, but not energy
Although bacteria and archaea have the same general cell structure, they are not closely related genetically.
true
Which of the following are classified as acellular infectious agents?
virus, viroid, prion
Unlike the term microorganism, the word microbe also includes ______.
viruses
Of the different ribosomal RNA molecules found in prokaryotes, which is the most useful in taxonomy?
16S
Under ideal conditions, Escherichia coli has a generation time of about 20 minutes. If 1 million cells were incubated in those conditions, approximately how many cells would be present after 1 hour?
8,000,000
Regardless of the pH of the external environment, microbial cells maintain a constant internal pH, typically near neutral. For example, prokaryotes that grow in alkaline conditions bring ____ into the cell.
PROTONS (H)
