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Flashcards in Chapter 27 Deck (89)
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1
Q

Earth’s first organisms were likely _.

A

Prokaryotes

2
Q

Most prokaryotes are _, although some species form colonies.

A

Unicellular

3
Q

Unlike eukaryotes, prokaryotes do not have _.

A

Membrane-bound organelles

4
Q

Prokaryotic cells are _ than eukaryotic cells.

A

Smaller

5
Q

Prokaryotic cells have a variety of _.

A

Shapes

6
Q

What are the two major bacteria groups?

A

Photoautotrophs (ex: algae) and chemoheterotrophs (ex: E. coli)

7
Q

How do antibiotics like penicillin work?

A

By puncturing holes in the cell wall of a bacterial cell

8
Q

What is quorum sensing?

A

How bacteria communicate with one another

9
Q

Prokaryotes thrive almost everywhere, including places too _, _, _, or _ for most other organisms (especially archaea, AKA extremophiles).

A

Acidic, salty, cold, or hot

10
Q

Prokaryotes are divided into two domains: _ and _.

A

Bacteria and Archaea

11
Q

An important feature of nearly all prokaryotic cells is their _.

A

Cell wall

12
Q

What are the functions of the cell wall of a prokaryotic cell?

A

Maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment

13
Q

Eukaryotic cell walls are made of _ or _.

A

Cellulose (plants) or chitin (exoskeletons and fungi)

14
Q

Bacterial cell walls contain _, a network of sugar polymers cross-linked by polypeptides (very rigid).

A

Peptidoglycan

15
Q

Archaea contain _ and _ but lack peptidoglycan.

A

Polysaccharides, proteins

16
Q

What is one way that scientists divide Bacteria and Archaea into two different domains?

A

Bacterial cell walls contain peptidoglycan whereas archaea cell walls do not

17
Q

Scientists use the _ to classify bacteria by cell wall composition.

A

Gram stain

18
Q

_ bacteria have simple cell walls with a large amount of peptidoglycan.

A

Gram-positive

19
Q

_ bacteria have more complex cell walls with an outer membrane and less peptidoglycan (these are the “mean” bacteria).

A

Gram-negative

20
Q

Which type of bacteria stains purple? Which type stains red?

A

Gram-positive; Gram-negative

21
Q

Many antibiotics trap _ and damage bacterial cell walls

A

Peptidoglycan

22
Q

Which type of bacteria is more likely to be antibiotic resistant?

A

Gram-negative

23
Q

A polysaccharide or protein layer called a _ covers many prokaryotes (outside of the cell).

A

Capsule

24
Q

Many prokaryotes form metabolically inactive _, which can remain viable in harsh conditions for centuries.

A

Endospores

25
Q

How do endospores remain viable in harsh conditions for centuries?

A

By entering a dormant state

26
Q

Some prokaryotes have _, which allow them to stick to their substrate or other individuals in a colony.

A

Fimbriae

27
Q

_ are longer than fimbriae and allow prokaryotes to exchange DNA.

A

Pili (or sex pili)

28
Q

Most motile bacteria propel themselves by _ that may be concentrated at one or both ends.

A

Flagella

29
Q

Flagella of bacteria, archaea, and eukaryotes are composed of different _ and likely evolved _.

A

Proteins; independently

30
Q

Prokaryotic cells usually lack _.

A

Complex compartmentalization

31
Q

Some prokaryotes have specialized _ that perform metabolic functions.

A

Membranes

32
Q

Membranes in prokaryotes are like _ in eukaryotes.

A

Organelles

33
Q

Membranes in a prokaryotic cell are usually _.

A

Infoldings of the plasma membrane

34
Q

The prokaryotic genome has _ than the eukaryotic genome.

A

Less DNA

35
Q

Most of the prokaryotic genome consists of a _.

A

Single circular chromosome

36
Q

The chromosome of a prokaryotic genome is not surrounded by a membrane; it is located in the _.

A

Nucleoid region

37
Q

Some species of bacteria also have smaller rings of DNA called _.

A

Plasmids

38
Q

Prokaryotes reproduce quickly by _ and can divide every _.

A

Binary fission; 1-3 hours

39
Q

Because binary fission does not allow for genetic variation in prokaryotic cells, there are three other factors that contribute to genetic diversity:

A

Rapid reproduction, mutation, and genetic recombination

40
Q

There are some differences between prokaryotes and eukaryotes in DNA _.

A

Replication, transcription, and translation

41
Q

_ rates during binary fission are low, but because of rapid reproduction, they can accumulate rapidly in a population.

A

Mutation

42
Q

Their short _ allows prokaryotes to evolve quickly.

A

Generation time

43
Q

The combining of DNA from two sources (contributes to diversity)

A

Genetic recombination

44
Q

Prokaryotic DNA from different individuals can be brought together by three processes: _, _, and _.

A

Transformation (take DNA from the environment), transduction (viruses move DNA from one organism to another), and conjugation (like sex)

45
Q

Movement of genes among individuals from different species is called _.

A

Horizontal gene transfer

46
Q

Prokaryotes can be categorized by how they obtain _ and _.

A

Energy and carbon

47
Q

_ obtain energy from light.

A

Phototrophs (think plants)

48
Q

_ obtain energy from chemicals.

A

Chemotrophs (think animals)

49
Q

_ require CO2 as a carbon source (from the air).

A

Autotrophs

50
Q

_ require an organic nutrient to make organic compounds (usually from other organisms).

A

Heterotrophs

51
Q

_ require O2 for cellular respiration.

A

Obligate aerobes

52
Q

_ are poisoned by O2 and use fermentation or anaerobic respiration.

A

Obligate anaerobes

53
Q

_ can survive with or without O2.

A

Facultative anaerobes

54
Q

Facultative anaerobes are _ compared two obligate aerobes/anaerobes.

A

Highly evolved

55
Q

_ is essential for the production of amino acids and nucleid acids.

A

Nitrogen

56
Q

Prokaryotes can _ nitrogen in a variety of ways.

A

Metabolize

57
Q

In _, some prokaryotes convert atmospheric nitrogen (N2) to ammonia (NH3).

A

Nitrogen fixation

58
Q

In the cyanobacterium Anabaeana, photosynthetic cells and nitrogen-fixing cells called _ exchange metabolic products.

A

Heterocysts (or heterocytes)

59
Q

_ between prokaryotes allows them use environmental resources they could not use as individual cells.

A

Metabolic cooperation

60
Q

Metabolic cooperation occurs between different prokaryotic species in surface-coating colonies called _.

A

Biofilms

61
Q

Give an example of a biofilm.

A

Plaque on teeth

62
Q

_ bacteria and _ bacteria on the ocean floor use each other’s waste products.

A

Sulfate-consuming; methane-consuming

63
Q

Advances in _ are beginning to reveal the extent of prokaryotic diversity.

A

Genomics

64
Q

Scientists continue to work on the _ of prokaryotes.

A

Phylogeny

65
Q

_ made possible the division of prokaryotes into two domains: Bacteria and Archaea.

A

Genetic analysis

66
Q

_ include the vast majority of prokaryotic species familiar to most people.

A

Bacteria

67
Q

Diverse _ type are represented among bacteria.

A

Nutritional

68
Q

Which type of bacteria do we come in contact with the most?

A

Proteobacteria

69
Q

Proteobacteria are _ and include photoautotrophs, chemoautotrophs, and heterotrophs.

A

Gram-negative

70
Q

Some proteobacteria are _, and others _.

A

Anaerobic, aerobic

71
Q

Give three examples of proteobacteria.

A
  • Rhizobium (wihich fixes atmospheric N2)
  • Agrobacterium (which is used in genetic engineering)
  • Helicobactor pylori (which causes stomach ulcers)
72
Q

_ share certain traits with bacteria and other traits with eukaryotes.

A

Archaea

73
Q

Some archaea live in extreme environments and are called _.

A

Extremophiles

74
Q

Extreme _ live in highly saline environments.

A

Halophiles

75
Q

Extreme _ thrive in very hot environments.

A

Thermophiles

76
Q

_ live in swamps and marshes and produce methane as a waste product.

A

Methanogens

77
Q

Methanogens are strict _.

A

Anaerobes (which means they are poisoned by O2

78
Q

What are some prokaryotic roles?

A

Chemical recycling, ecological interactions, research and technology, and bioremediation

79
Q

Chemoheterotrophic prokaryotes function as _, breaking down dead organisms and waste products.

A

Decomposers

80
Q

Prokaryotes can sometimes increase the availability of _, _, and _ for plant growth.

A

Nitrogen, phosphorus, potassium

81
Q

Symbiosis

A

An ecological relationship in which two species live in close contact

82
Q

What are the two roles in symbiosis?

A

A larger host and a smaller symbiont

83
Q

How many species of bacteria live in our intestines?

A

About 500-1,000

84
Q

Many of the species of bacteria living in our intestines are _ and break down food that is undigested by our intestines.

A

Mutualists

85
Q

The bacteria within humans that aid in digestion and defense is termed the _.

A

Microbiome

86
Q

Bacteria cause about half of all _.

A

Human diseases

87
Q

Some _ are transmitted by other species.

A

bacterial diseases

88
Q

Experiments using prokaryotes have led to important advances in _.

A

DNA technology

89
Q

What can we now make using bacteria?

A

Natural plastics, vitamins, antibiotics, and hormones