Chapter 26: Prokaryotes- Bacteria And Archaea

Question 1

Bacteria

Answer 1

One of the two domains of prokaryotes, collectively, bacteria are the most metabolically diverse organisms.

Question 2

Archaea

Answer 2

One of two domains of prokaryotes; archaeans have some unique molecular and biochemical traits, but they also share some traits with bacteria and other traits with eukarya.

Question 3

Eukarya

Answer 3

The domain that includes all eukaryotes, organisms that contain a membrane-bound nucleus within each of their cells; all protists, plants, fungi, and animals.

Question 4

Plasmids

Answer 4

A DNA molecule in the cytoplasm of certain prokaryotes, which often contains genes with functions that supplement those in the nucleoid and which can replicate independently of the nucleoid DNA and be passed along during cell division.

Question 5

Nucleoid

Answer 5

The central region of a prokaryotic cell with no boundary membrane separating it from the cytoplasm, where DNA replication and RNA transcription occur.

Question 6

Autotrophs

Answer 6

An organism that produces its own food using CO2 and other simple inorganic compounds from its environment and energy from the Sun or from oxidation of inorganic substances.

Question 7

Heterotrophs

Answer 7

An organism that acquires energy and nutrients by eating other organisms or their remains.

Question 8

Chemotrophs

Answer 8

An organism that obtains energy by oxidizing inorganic or organic substances.

Question 9

Phototrophs

Answer 9

Obtain energy from light

Question 10

Chemoautotrophs

Answer 10

Obtain energy by oxidizing inorganic substances such as hydrogen, iron, sulfur, ammonia, nitrites, and nitrates and use CO2 as their carbon source. Not found among Eukaryots

Question 11

Photoautotrophs

Answer 11

Photosynthetic organisms that use light as their energy source and CO2 as their carbon source. Includes several groups of bacteria, for example Cyanobacteria.

Question 12

Aerobes

Answer 12

An organism that requires oxygen for cellular respiration.

Question 13

Obligate aerobes

Answer 13

A microorganism that uses oxygen for cellular respiration and requires oxygen in its surroundings to support growth.

Question 14

Anaerobes

Answer 14

An organism that does not require oxygen to live.

Question 15

Obligate anaerobes

Answer 15

A microorganism that cannot use oxygen and can only grow only in the absence of oxygen. (Poisoned by oxygen, survive by fermentation or another form of respiration)

Question 16

Facultative anaerobes

Answer 16

Use CO2 when present, but under anaerobic conditions they live by fermentation.

Question 17

Nitrogen fixation

Answer 17

A metabolic process in which certain bacteria and Cyanobacteria convert molecular nitrogen into ammonia and ammonium ions, forms usable by plants.

Reducing atmospheric nitrogen (N2) to ammonia (NH3)

Question 18

Nitrification

Answer 18

A metabolic process in which soil bacteria convert ammonia (NH4+) into nitrate ((NO3-). One bacteria converts ammonia to nitrite (NO2-), whereas the other converts nitrite to nitrate.

Question 19

Horizontal gene transfer

Answer 19

Movement of genetic material between organisms other than descent.

Question 20

Endospore

Answer 20

A small, metabolically inactive, asexual spore that develops within some bacterial cells when environmental conditions become unfavorable.

Question 21

Biofilm

Answer 21

A prokaryotic multicellular association consisting of a complex aggregation of microorganisms (either one or multiple species) attached, in most cases to a surface.

Question 22

Exotoxins

Answer 22

A toxic protein that leaks from or is secreted from a bacterium and interferes with the biochemical processes of body cells in various ways.

Question 23

Endotoxins

Answer 23

A lipopolysaccharide released from the outer membrane of the cell wall when a bacterium dies and lyses.