AP Bio Ch. 27 (8th Edition) Flashcards

Flashcards for Ch. 27 (8th Edition)

90123413	Peptidoglycan	A type of polymer in bacterial cell walls consisting of modified sugars cross-linked by short polypeptides; encloses entire bacterium and anchors other molecules that extend from its surface	0
90123414	Gram Stain	A staining method that distinguishes between two different kinds of bacterial cell wall	1
90123415	Gram-Negative	Have a cell wall that is more structurally complex and contains LESS peptidoglycan; often more toxic	2
90123416	Gram-Positive	Have a cell wall that is less structurally complex and contains MORE peptidoglycan; often less toxic	3
90123417	Capsule	A sticky layer that surrounds the cell wall of some prokaryotes, protecting the cell surface and sometimes helping to glue the cell to surfaces	4
90123418	Fimbria (Fimbriae)	A short, hairlike apendage of a prokaryotic cell that helps it adhere to the substrate or to other cells; also known as attachment pilus	5
90123419	Sex Pilus (Sex Pili)	A structure that links one cell to another at the start of conjugation; also known as conjugation pilus	6
90123420	Taxis	An oriented movement toward or away from a stimulus	7
90123421	Nucleoid	Building block of nucleic acid, consisting of a 5-carbon sugar, covalently bonded to a nitrogenous base and a phosphate group	8
90123422	Plasmids	A small, circular, double-stranded DNA molecule that carries accessort genes separate from those of a bacterial chromosome; found in some eukaryotes (yeast)	9
90123423	Endospore	A thick-coated, resistant cell produced by a bacterial cell exposed to harsh conditions	10
90123424	Transformation	A change in genotype/phenotype due to the assimilation of external DNA by a cell	11
90123425	Transduction	A type of horizontal gene transfer in which bacteriophages (viruses) carry bacterial DNA from one host cell to another	12
90123426	Conjugation	In prokaryotes, the direct transfer of DNA between two cells (of the same or different species) that are temporarily joined	13
90123427	F Factor	The DNA segment that confers the ability to form pili for conjugation and associated functions required for the transfer of DNA from donor to recipient	14
90123428	F Plasmid	The plasmid form of the F factor	15
90123429	R Plasmid	A bacterial plasmid carrying genes that confer resistance to certain antibiotics	16
90123430	Photoautotroph	An organism that harnesses LIGHT energy to drive the synthesis of organic compounds from carbon dioxide	17
90123431	Chemoautotroph	An organism that needs only carbon dioxide as a carbon source but obtains energy by oxidizing inorganic substances	18
90123432	Photoheterotroph	An organism that uses light to generate ATP but must obtain carbon in organic form	19
90123433	Chemoheterotroph	An organism that must consume organic molecules for both energy and carbon	20
90123434	Obligate Aerobes	An organism that requires oxygen for cellular respiration and cannot live w/o it	21
90123435	Obligate Anaerobes	An organism that only carries out fermentation or anaerobic respiration; cannot use oxygen	22
90123436	Anaerobic Respiration	the use of inorganic molecules other than oxygen to accept electrons at the "downhill" end of electron transport chains	23
90123437	Facultative Anaerobes	An organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present	24
90123438	Extremophile	An organism that lives in an environment whose conditions are so extreme that few other species can survive there	25
90123439	Extreme Halophiles	An organism that lives in a highly saline environment, such as the Great Salt Lake or the Dead Sea	26
90123440	Extreme Thermophiles	An organism that thrives in hot environments (60-80 Celsius or hotter)	27
90123441	Methanogens	An organism that obtains energy by using carbon dioxide to oxidize hydrogen, producing methane as a waste product	28
90123442	Decomposer	An organism that absorbs nutrients from nonliving organic material such as corpses, fallen plant material, and the wastes of living organisms and converts them to inorganic forms; a detritivore	29
90123443	Symbiosis	An ecological relationship between organisms of two different species that live together in direct and intimate contact	30
90123444	Host	The larger participant in the symbiotic relationship, serving as home and food source for the smaller symbiont	31
90123445	Symbiont	The smaller participant in the symbiotic relationship, living in or on the host	32
90123446	Mutualism	A symbiotic relationship in which both participants benefit	33
90123447	Commensalism	A symbiotic relationship in which one organism benefits but the other is neither helped nor harmed	34
90123448	Parasitism	A symbiotic relationship in which one organism, the parasite, benefits at the expense of another, the host, by living either within or on the host	35
90123449	Parasite	An organism that feeds on the cell contents, tissues, or body fluids of another species (the host) while in or on the host organism; they usually harm, but do not kill, the host	36
90123450	Pathogen	An organism/virus that causes disease	37
90123451	Exotoxin	A toxic protein that is secreted by a prokaryote or other pathogen and that produces specific symptoms, even if the pathogen is no longer present	38
90123452	Endotoxin	A toxic component of the outer membrane of certain gram-negative bacteria that is released only when the bacteria die	39
90123453	Bioremediation	The use of organisms to detoxify and restore polluted and degraded ecosystems	40