Lab Ex 24 Survey of Bacteria

Question 1

Prokaryotes

Answer 1

5000+ species with cells lacking membrane-bound organelles

Question 2

Eukaryotes

Answer 2

species with cells with membrane-bound organelles

Question 3

Domains

Answer 3

classification of all living groups of organisms with different DNA sequences into 3 areas

Question 4

Domain Archaea

Answer 4

includes Kingdom Archaebacteria (prokaryotes); often inhabit but are not restricted to extreme and stressful environments on Earth; may be oldest forms of life on Earth

Question 5

Domain Bacteria

Answer 5

includes Kingdom Bacteria (prokaryotes) and most abundant organisms on Earth

Question 6

Domain Eukarya

Answer 6

includes kingdoms Protista, Fungi, Plantae, and Animalia

Question 7

Extremophiles

Answer 7

AKA Archaebacteria, due to their environments being extremely acidic, hot, or salty

Question 8

Heterotrophic

Answer 8

most bacteria; derive energy from organic molecules made by other organisms

Question 9

Decomposers

Answer 9

heterotrophic bacteria are considered this because they feed on dead organic matter and release nutrients locked in dead tissue

Question 10

Autotrophic

Answer 10

bacteria that derive their energy from photosynthesis or the oxidation of inorganic molecules

Question 11

Fission

Answer 11

bacteria reproduce asexually via this method in which a cell’s DNA replicates and the cell pinches in half without the nuclear and chromosomal events associated with mitosis

Question 12

Conjugation

Answer 12

some bacteria have genetic recombination via this method, in which all or part of the genetic material of one bacterium is transferred to another bacterium and a new set of genes is assembled

Question 13

Gram stain

Answer 13

one of the most important techniques to classify bacteria named after Hans Christian Gram; based on the different structural and chemical compositions of bacterial cell walls; often correlates with the sensitivity of a bacterium to antibiotics

Question 14

Gram-positive bacteria

Answer 14

ex. Streptococcus, Micrococcus; have a thick cell wall that retains a purple dye

Question 15

Gram-negative bacteria

Answer 15

ex. E. Coli, Serrati; have a much thinner cell wall that does not retain the dye; safranin is used to counterstain with a red color

Question 16

Endospores

Answer 16

tolerance to stress is enhanced in C. botulinum and many other bacteria by the formation of thick-walled these that surround their chromosome and a small portion of the surrounding cytoplasm

Question 17

Nitrogen fixation

Answer 17

certain bacteria and cyanobacteria transform atmospheric nitrogen (N2) into other nitrogenous compounds that can be used as nutrients by plants

Question 18

Rhizobium

Answer 18

bacterium that can fix nitrogen and can grow intimately with roots of some plants called legumes (clover, alfalfa, soybeans)

Question 19

Nodules

Answer 19

associations between Rhizobium and host roots from these on the roots; = resident nitrogen-fixers that provide ammonia to the plant while the plant provides sugars and other nutrients to the bacteria

Question 20

Sensitivity plate

Answer 20

petri dish of solid medium that has been uniformly inoculated on its entire surface with a known bacterium or an unknown sample from an infected patient

Question 21

Cyanobacteria pigments

Answer 21

chlorophyll a, phycocyanin (blue), & phycoerythrin (red)

Question 22

Sheath

Answer 22

cyanobacteria reproduce by fission and are often surrounded by a jellylike _______

Question 23

Trichomes

Answer 23

oscillatoria (cyanobacteria) grows as long chains of cells called this

Question 24

Nostoc

Answer 24

cyanobacteria commonly called witch’s butter or starjelly; forms large, grapelike colonies; consists of small vegetative cells and larger, thick-walled heterocysts

Question 25

Heterocysts

Answer 25

larger, thick-walled cells in which nitrogen fixation occurs