CH. 27

Question 1

are prokaryotes or eukaryotes the most abundant organisms on earth and why

Answer 1

prokaryotes, ability to adapt to a broad range of habitats

Question 2

are most prokaryotes multicellular or unicellular

Answer 2

unicellular

Question 3

a key feature of all prokaryotes is the __ ___

Answer 3

cell wall

Question 4

in a ___ environment, most prokaryotes lose water and shrink away from their wall, inhibiting __ ___

Answer 4

hypertonic, cell reproduction

Question 5

in eukaryotes that have cell walls, the walls are usually made of ___ or ___

Answer 5

cellulose, chitin

Question 6

most bacterial cell walls contain ____

Answer 6

peptidoglycan

Question 7

polymer composed of modified sugars cross-linked by short polypeptides

Answer 7

peptidoglycan

Question 8

staining method that distinguishes between two different kinds of bacterial cell walls, may be used to help determine medical response to an infection

Answer 8

gram stain

Question 9

what are the steps of a gram stain

Answer 9

1) samples are stained with crystal violet dye and iodine
2) samples are rinsed in alcohol
3) samples are stained with a red dye such as safranin that enters the cell and binds to its DNA

Question 10

___-___ bacteria have relatively simple walls composed of a thick layer or peptidogylcan

Answer 10

gram positive

Question 11

the walls of ___-____ bacteria have less peptidoglycan and are structurally more complex, with an outer membrane that contains lipopolysaccharide

Answer 11

gram negative

Question 12

dense and well0defined layer of polysaccharide or protein that surrounds the cell wall and is sticky

Answer 12

capsule

Question 13

a thick-coated, resistant cell produced by some bacterial cells when they are exposed to harsh conditions

Answer 13

endospore

Question 14

short, hairlike appendage of a prokaryotic cell that helps it adhere to the substrate or to other cells

Answer 14

fimbria

Question 15

appendages that pull two cells together prior to DNA transfer from one cell to the other

Answer 15

pili

Question 16

fimbria are usually (taller/shorter) and (more/less) numerous than pili

Answer 16

shorter, more

Question 17

directed movement toward or away from a stimulus

Answer 17

taxis

Question 18

what are the three main parts of the bacterial flagellum

Answer 18

motor, hook, filament

Question 19

process in which structures originally adapted for one function rake on new functions through descent with modification

Answer 19

exaptation

Question 20

prokaryotes lack a ____, their chromosome is located in the ___

Answer 20

nucleus, nucleoid

Question 21

smaller rings of independently replicating dna molecules found in a typical prokaryotic cell

Answer 21

plasmids

Question 22

prokaryotes reproduce through ___ ___

Answer 22

binary fission

Question 23

three key features of prokaryotic biology

Answer 23

small, reproduce by binary fission, have short generation times

Question 24

what are the three factors that give rise to high levels of genetic diversity in prokaryotes

Answer 24

rapid reproduction, mutation, genetic recombination

Question 25

what 2 processes combine dna from 2 individuals in a single zygote for eukaryotes

Answer 25

meiosis, fertilization

Question 26

what are the 3 mechanisms that can being together prokaryotic DNA from different individuals

Answer 26

transformation, transduction, conjugation

Question 27

when the individuals are members of different species, the movement of genes from one organism to another is called

Answer 27

horizontal gene transfer

Question 28

in ____, the genotype and possibly phenotype of a prokaryotic cell are altered by the uptake of foreign DNA from its surroundings

Answer 28

transformation

Question 29

in ___, phages carry prokaryotic genes from one host cell to another

Answer 29

transduction

Question 30

in __, dna is transferred between two prokaryotic cells that are temporarily joined

Answer 30

conjugation

Question 31

particular piece of dna that results in the ability to form pili and donate DNA during conjugation

Answer 31

f factor

Question 32

bacterial plasmid carrying genes that confer resistance to certain antibiotics

Answer 32

r plasmid

Question 33

organisms that obtain energy from light

Answer 33

phototrophs

Question 34

organisms that obtain energy from chemicals

Answer 34

chemotrophs

Question 35

organisms that need only co2 or related compounds as a carbon source

Answer 35

autotrophs

Question 36

require at least one organic nutrient to make other organic compounds

Answer 36

heterotrophs

Question 37

organisms that must use o2 for cellular respiration and cannot grow without it

Answer 37

obligate aerobes

Question 38

organisms that carry out only fermentation or anaerobic respiration, are poisoned by oxygen

Answer 38

obligate anaerobes

Question 39

a catabolic pathway in which inorganic molecules other than oxygen accept electrons at the downhill end of electron transport chains

Answer 39

anaerobic respiration

Question 40

use o2 if present but can carry out fermentation or anaerobic respiratoin in an anaerobic environment

Answer 40

facultative anaerobes

Question 41

conversion of atmospheric nitrogen to ammonia

Answer 41

nitrogen fixation

Question 42

specialized cell that engages in nitrogen fixation in some filamentous cyanobacteria

Answer 42

heterocyst

Question 43

surface coating colony of one or more species of prokaryotes that engage in metabolic cooperation

Answer 43

biofilm

Question 44

organism that lives in environmental conditions so extreme that few other species can survive there

Answer 44

extremophile

Question 45

___ ___ live in highly saline environments

Answer 45

extreme halophiles

Question 46

___ ___ thrive in very hot environments

Answer 46

extreme thermophiles

Question 47

archaea that release methane as a by product of their unique ways of obtaining energy

Answer 47

mehanogens

Question 48

ecological relationship in which two species live in close contact with each other

Answer 48

symbiosis

Question 49

the large organism in a symbiotic relationship

Answer 49

host

Question 50

the smaller organism in a symbiotic relationship

Answer 50

symbiont

Question 51

ecological relationship in which one species benefits while the other is not harmed or helped in any significant way

Answer 51

commensialism

Question 52

parasites that cause disease

Answer 52

pathogens

Question 53

proteins secreted by certain bacteria and other organisms

Answer 53

exotoxins

Question 54

lipopolysaccharide components of the outer membrane of gram-negative bacteria released only when bacteria die and their cell walls break down

Answer 54

endotoxins

Question 55

technique for editing genes in living cells, involving a bacterial protein associated with a guide rna complementary to a gene sequence of interest

Answer 55

crispr-cas9 system

Question 56

use of organisms to remove pollutants from soil, air, or water

Answer 56

bioremediation

Question 57

what are the 3 domain

Answer 57

eubacteria, archaea, eukarya

Question 58

what is the kingdom under eubacteria and archaea

Answer 58

monera

Question 59

what are the 4 kingdoms under eukarya

Answer 59

protista, fungi, plantae, animalia

Question 60

do prokaryotes have membrane bound organelles?

Answer 60

no