Chapter 24: Early Life/Diversification of Prokaryotes

Question 1

What are the 3 domains of life?

Answer 1

Eukaryotes, Archaea, + Bacteria

Question 2

What domains are prokaryotes in?

Answer 2

Bacteria + Archaea

Question 3

What is a prokaryote?

Answer 3

a single-celled organism in the domains Bacteria + Archaea

Question 4

What is a nucleoid?

Answer 4

an area in which genetic materials are assembled/loosely organized/have no membrane

Question 5

What are the prokaryote shapes?

Answer 5

Spherical (cocci), rod-shaped (bacilli), + spiral (Spirilla)

Question 6

What is the function of the cell wall?

Answer 6

maintain shape and protect

Question 7

What is the function of the capsule?

Answer 7

enables prokaryotes to adhere to substrates or other prokaryotes

Question 8

What is the function of the plasma membrane?

Answer 8

acts as a selective barrier

Question 9

What is the function of a fimbriae?

Answer 9

enables prokaryotes to adhere to substrates or other prokaryotes

Question 10

What is the function of the pilus?

Answer 10

appendages that pull 2 cells together before DNA transfer

Question 11

What is the function of the flagella?

Answer 11

enables taxis (mobility)

Question 12

What is the function of ribosomes?

Answer 12

contains RNA

Question 13

What are cell walls in prokaryotes (Domain Bacteria) made of?

Answer 13

peptidoglycan

Question 14

What is gram-positive bacteria?

Answer 14

bacteria that stains a darker color due to its thick peptidoglycan cell wall

Question 15

What is gram-negative bacteria?

Answer 15

bacteria that has a thinner peptidoglycan cell wall - makes its more resistant to drugs

Question 16

What are plasmids?

Answer 16

smalls rings of independently replicating DNA, located in the nucleoid

Question 17

What is the internal organization of prokaryotes?

Answer 17

-Lack complex compartments
-Some have specialized membranes
-The membrane = plasma infoldings

Question 18

What is a phototroph?

Answer 18

organisms that obtain energy from light

Question 19

What is a chemotroph?

Answer 19

organisms that obtain energy from chemicals

Question 20

What is an extremophile?

Answer 20

Prokaryotes that love extreme environments

Question 21

What is a thermophile?

Answer 21

prokaryotes that can live in very hot environments

Question 22

What is an acidophile?

Answer 22

prokaryotes that can live in very acidic environments

Question 23

What is a halophile?

Answer 23

prokaryotes that can live in very salty environments

Question 24

What is a psychcrophile?

Answer 24

prokaryotes that can live in very cold environments

Question 25

What is a biofilm?

Answer 25

a surface coating colony of 1 or more species of prokaryotes that engage in metabolic cooperation (slime on a lake, grime on teeth)

Question 26

What are obligate aerobes?

Answer 26

use oxygen for cellular respiration

Question 27

What are obligate anaerobes?

Answer 27

fermentation/use of molecules that are not oxygen like NO3. Oxygen is poisonous to them.

Question 28

What is metabolic cooperation?

Answer 28

-singles cells that can't carry out 2 processes at once -enables access to additional resources -occurs in biofilms

Question 29

What are nitrogen-fixing cyanobacteria?

Answer 29

photosynthetic cells that make sugar

Question 30

What are heterocysts?

Answer 30

fix N2

Question 31

What process do prokaryotes use to reproduce?

Answer 31

binary fission

Question 32

What prevents reproduction in prokaryotes?

Answer 32

-depleted nutrients + metabolic wastes -competition -predators

Question 33

What is mutualism?

Answer 33

a relationship where both species benefit

Question 34

What is commensalism?

Answer 34

a relationship where one species benefits while the other is not benefited nor harmed

Question 35

What is parasitism?

Answer 35

a relationship where one species benefits while the other is harmed

Question 36

What is symbiosis?

Answer 36

when two species live in close contact

Question 37

What is bioremediation

Answer 37

a process using living organisms to remove pollutants from soil, air, and water

Question 38

How do prokaryotes have a high level of genetic diversity?

Answer 38

rapid reproduction, mutations, and genetic recombination

Question 39

What is genetic recombination?

Answer 39

the combining of DNA from 2 sources

Question 40

What horizontal gene transfer?

Answer 40

the movement of genes from one organism to another

Question 41

What are the three mechanisms in horizontal gene transfer?

Answer 41

1. Transformation 2. Transduction 3. Conjugation

Question 42

What is transformation?

Answer 42

the uptake of foreign DNA from surroundings

Question 43

What is transduction?

Answer 43

bacteriophages carry prokaryotic genes from one host cell to another

Question 44

What is conjugation?

Answer 44

The DNA transfer between 2 prokaryotes

Question 45

What are proteobacteria?

Answer 45

-Aerobes/anaerobes -gram-negative -has five sub-groups (alpha, beta, gamma, delta, and epsilon)

Question 46

What are sister bacteria?

Answer 46

chlamydia, spriochetes, cyanobacteria, gram-positive

Question 47

What are the four stages of early life on earth?

Answer 47

1. The abiotic synthesis of small/organic molecules 2. The abiotic joining of small organic molecules into macromolecules 3. The packaging of these molecules to protocells 4. The origin of self-replication molecules