Unit 1 Ch 1 - Exploring the Microbial World

Question 1

Aseptic technique

Answer 1

the manipulation of sterile instruments or culture media in such a way as to maintain sterility

Question 2

Cell wall

Answer 2

a rigid layer present outside the cytoplasmic membrane; it confers structural strength on the cell

Question 3

Chemolithotrophy

Answer 3

a form of metabolism in which energy is generated from the oxidation of inorganic compounds

Question 4

Colony

Answer 4

a macroscopically visible population of cells growing on solid medium, arising from a single cell

Question 5

Contrast

Answer 5

the ability to resolve a cell or structure from its surroundings

Question 6

Culture

Answer 6

a collection of microbial cells grown using a nutrient medium

Question 7

Cytoplasm

Answer 7

the fluid portion of a cell, enclosed by the cytoplasmic membrane

Question 8

Differentiation

Answer 8

modification of cellular components to form a new structure, such as a spore

Question 9

Domain

Answer 9

one of the three main evolutionary lineages of cells: the Bacteria; the Archaea, and the Eukarya

Question 10

DNA replication

Answer 10

the process by which information from DNA is copied into a new strand of DNA

Question 11

Enrichment culture technique

Answer 11

a method for isolating specific microorganisms from nature using specific culture media and incubation conditions

Question 12

Enzyme

Answer 12

a protein (or in some cases RNA) catalyst that functions to speed up chemical reactions

Question 13

Eukaryotic

Answer 13

having a membrane-enclosed nucleus and various other membrane-enclosed organelles; cells of Eukarya

Question 14

Evolution

Answer 14

a change over time in gene sequence and frequency within a population of organisms, resulting in descent with modification

Question 15

Extremophiles

Answer 15

microorganisms that inhabit environments characterized by extremes of temperature, pH, pressure or salinity

Question 16

Genome

Answer 16

an organism’s full complement of genes

Question 17

Gram-negative

Answer 17

a bacterial cell with a cell wall containing small amounts of peptidoglycan and an outer membrane

Question 18

Gram-positive

Answer 18

a bacterial cell whose cell wall consists chiefly of peptidoglycan; it lacks the outer membrane of gram-negative cells

Question 19

Gram stain

Answer 19

a differential staining procedure that stains cells either purple (gram-positive) or pink (gram-negative)

Question 20

Growth

Answer 20

in microbiology, an increase in cell number with time

Question 21

Gut microbiome

Answer 21

the microbial communities present in the animal gastrointestinal tract

Question 22

Horizontal gene transfer

Answer 22

the transfer of genes between cells through a process uncoupled from reproduction

Question 23

Intercellular communication

Answer 23

interactions between cells through a process using chemical signals

Question 24

Koch’s postulates

Answer 24

a set of criteria for proving that a given microorganism causes a given disease

Question 25

Macromolecules

Answer 25

a polymer of monomeric units, for example proteins, nucleic acids, polysaccharides and lipids

Question 26

Medium (plural: media)

Answer 26

in microbiology, the liquid or solid nutrient mixture(s) used to grow microorganisms

Question 27

Magnification

Answer 27

the optical enlargement of an image

Question 28

Metabolism

Answer 28

all biochemical reactions in a cell

Question 29

Microbial community

Answer 29

two or more populations of cells that coexist and interact in a habitat

Question 30

Microbial ecology

Answer 30

the study of microorganisms in their natural environments

Question 31

Microorganism

Answer 31

an organism that is too small to be seen by the unaided human eye

Question 32

Motility

Answer 32

the movement of cells by some form of self-propulsion

Question 33

Nucleoid

Answer 33

the aggregated mass of DNA that makes up the chromosome(s) of prokaryotic cells

Question 34

Nucleus

Answer 34

a membrane-enclosed structure in eukaryotic cells that contains the cell’s DNA genome

Question 35

Organelle

Answer 35

a bilayer-membrane-enclosed structure such as the mitochondrion, found in eukaryotic cells

Question 36

Pathogen

Answer 36

a disease-causing microorganism

Question 37

Phylogenetic tree

Answer 37

a diagram that depicts the evolutionary history of organisms

Question 38

Phylogeny

Answer 38

the evolutionary history of organisms

Question 39

Plasmid

Answer 39

an extrachromosomal genetic element that is not essential for growth

Question 40

Prokaryotic

Answer 40

lacking a membrane-enclosed nucleus and other organelles; cells of Bacteria or Archaea

Question 41

Pure culture

Answer 41

a culture containing a single kind of microorganism

Question 42

Resolution

Answer 42

the ability to distinguish two objects as distinct and separate when viewed under the microscope

Question 43

Ribosomes

Answer 43

a structure composed of RNAs and proteins upon which new proteins are made

Question 44

Ribosomal RNA (rRNA)

Answer 44

the types of RNA found in the ribosome

Question 45

Spontaneous generation

Answer 45

the hypothesis that living organisms can originate from nonliving matter

Question 46

Sterile

Answer 46

Free of all living organisms (cells) and viruses

Question 47

Transcription

Answer 47

the synthesis of an RNA molecule complementary to one of the two strands of a double-stranded DNA moleculeT

Question 48

Translation

Answer 48

the synthesis of protein by a ribosome using the genetic information in a messenger RNA as a template