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Flashcards in An Introduction to Bacteria Deck (57)
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31

What provides a mechanism for antibiotic resistance?

The plasmid

32

What kinds of bacteria prefer what during mating?

Gram negative prefers gram negative

Gram positive prefers gram positive

33

What is conjugation?

Process by which bacterium transfers genetic material to another through direct contact

34

What are other names for gram positive and gram negative bacteria?

F+ are gram positive

F- are gram negative

35

What do gram positive bacteria contain in terms of mating?

F plasmid which allows them to form F pills

36

What eventually happens when gram positive and gram negative bacteria are mixed together?

They all become gram positive

37

What is the process of conjugation?

1) F pills of donor cell (gram positive) recognises and binds to proteins on gram negative cell wall

2) Plasmid becomes mobilised for transfer

3) Single strand of plasmid enters the recipient cell

4) Inside recipient cell a complimentary strand is synthesised

38

What is binary fussion?

The process by which bacteria replicates

39

What may genetic variation occur due to?

Spontaneous mutations

Transfer of DNA

40

What are spontaneous mutations?

Mutations that occur randomly with no influence from the environment

41

What does transfer of DNA occur by?

Conjugation

Transformation

Transduction

42

What is transformation?

Genetic alteration due to uptake of extracellular DNA that is advantageous

43

What is transduction?

Foreign DNA is introduced into a cell by a virus

44

What is transduction caused by?

Bacteriophages

45

What are bacteriophages?

Viruses that infect bacteria

46

What do bacteriophages contain?

Head

Collar

Tail

End plate

Tail fibre

47

What does the end plate and the tail on a bacteriophage do?

Helps it to attach to bacteria cells

48

What are the two cycles that bacteriophages enter their DNA into bacteria through?

Lytic

Lysogenic

49

What is the lytic cycle?

Where the phage overtakes the machinery in the bacteria and starts replicating to form more phages, bacteria cell then bursts and releases them

50

What is the lysogenic cycle?

DNA from the phage integrates with the hosts chromosome, it can remain dormant or replicate

51

What can individual bacteria be seen by?

Microscope at 1000x with an oil immersion lens

Staining (such as gram or flourescent)

52

What can the naked eye see?

Colonies of bacteria

53

What is culturing used for?

To identify exactly what species of bacteria is present

54

What do selective mediums allow?

Certains species to grow

55

What is bacteria naming based on?

The genus and the species

For example for Staphylococcus aureus Staphylococcus is the genus and aureus is the species

56

What properties do strains of bacteria within the same species have?

Similar characteristics

57

What can be used to identify strains?

DNA typing