Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mbg 2040 > Lecture 13-15 > Flashcards

Lecture 13-15 Flashcards

1
Q

What makes bacteria valuable for research

A

small size, rapid reproduction, simple structure, genetic variability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What are the 3 parasexual processes

A

conjugation, transformation and transduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the term for bacterial viruses

A

bacteriophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do bacteriophages reproduce

A

infecting bacterial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the two media options for bacterial growth

A

liquid and solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the circular features on a solid media if bacteria growth occurs

A

colonies of bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

If you assembled a full dish of bacterial growth and then inserted a virus, clearings would show up on the plate, what are these clearings called

A

plaques

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why do plaques occur

A

the virus kills the bacteria in the colony and forms clearings where the bacteria previously was

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is bacteriophage T4

A

the genome contains 168800 base pairs and 150 characterized genes
- goes through a lytic phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a lytic phase

A

infects host, lyses host, and bursts to infect surrounding cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a lysogenic phase

A

bacteriophage DNA is inserted onto the host genome where it is passed on to subsequent generations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Is bacteriophage T4 a lytic of lysogenic phage

A

lytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is bacteriophage lambda

A

genome contains 48502 base pairs and about 50 genes (smaller than T4)
- can be both lytic or lysogenic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In its integrated state, the lambda chromosome is called….

A

prophage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why can bacteria not have chiasmata

A

they don’t have meiosis, only mitosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is the gene transfer of bacteria unidirectional or bidirectional

A

unidirectional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are plasmids

A

small circular DNA sequences (episomes are a subcategory of plasmids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some examples of phenotypes in bacteria

A

colony colour, nutritional mutants, phototrophs (wild type) and auxotrophs (cannot synthesize certain AAs), and antibiotic resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are prototrophs

A

wild type bacterial chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are auxotrophs

A

cannot synthesize certain AAs

20
Q

What is conjugation

A

a cytoplasmic bridge is formed between two bacterial cells and DNA replicates and transfers from donor to recipient
- crossover then occurs to implement new DNA onto original plasmid and a recombinant chromosome appears

21
Q

What is transformation

A

DNA fragments from a dead cell in the colony (naked DNA) is taken up by a host
- a crossover then occurs to implement new DNA onto original plasmid and a recombinant chromosome appears

22
Q

What is transduction

A

a virus attaches itself to a host bacterial cell and injects its DNA, which splits up the original chromosome of the host cell
- the bacterial cell lyses, however, some of the bacterial DNA is taken up by the viral head and transferred to the next host cell
- a crossover the occurs to implement new DNA onto original plasmid and a recombinant chromosome appears

23
Q

What parasexual process requires physical contact

A

conjugation

24
Q

What parasexual process requires a virus

A

transduction

25
Q

What parasexual process is sensitive to DNase

A

transformation

26
Q

Why is transformation sensitive to DNase

A

because the function of DNase is to chop up free floating DNA and make it useless to the cell - in this case transformation would not occur because the free DNA outside the cell would no longer be viable

27
Q

What experiment determined the need for contact in bacterial DNA conjugation

A

the U-tube experiment

28
Q

In what parasexual process does a bacterial cell take up DNA from its outer environment

A

transformation

29
Q

What does it mean for a bacterium to be competent

A

can bind exogenous DNA and transport it into the cell (therefore bacterium must be competent to undergo transformation)

30
Q

What can transformation be used to determine

A

distance between bacterial genes

31
Q

How is transformation measured

A

as a change in phenotype (which occurs at a certain frequency)

32
Q

How does transformation determine the distance between genes on the original chromosome

A

because when looking at the uptake of varying DNA fragments, different results are seen in the transformants

ie. if a+ b+ and c+ are all fragments of donor DNA, and uptake of a+ alone, b+ alone, c+ alone, and a+b+ together are seen, that would mean a and b were close together on the original plasmid, while c was further away (don’t see a+c+ together or b+c+ together)

33
Q

Is conjugation sexual or asexual

A

sexual reproduction mediated by the F factor (fertility factor)

34
Q

What physical formation is F factor

A

it is an episome

35
Q

In conjugation, what is ALWAYS a recipient cell and cannot act as a donor

A

F- cells (don’t have fertility factor to donate)

36
Q

What is a cell with F factor NOT incorporated into the chromosome called

A

F+ cell (has autonomous F factor)

37
Q

What is a cell with F factor incorporated into the chromosome called

A

Hfr cell (has integrated F factor)

38
Q

What are the two cell types that can act as donors in conjugation

A

F+ cells and Hfr cells

39
Q

What is the product of conjugation between an F+ cell and an F- cell

A

2 F+ cells

40
Q

What is the product of conjugation between an Hfr cell and an F- cell

A

an F- cell and an Hfr cell

41
Q

What occurs in the conjugation of an Hfr and an F- cell

A

the Hfr acts as the donor and the F- cell acts as the recipient, Hfr synthesizes its DNA and inserts it onto the recipient for genetic recombination, but the F factor is not passed on to the recipient (no change in cell type, only see recombination of DNA)

42
Q

What occurs in the conjugation of an F- cell and an F+ cell

A

the F+ cell acts as the donor, and the F- cell acts as the recipient, the F factor in the F+ cell synthesizes its DNA and it crosses over the bridge into the recipient cell to form autonomous F factor in the recipient, therefore the recipient becomes F+ and two F+ cells are seen as the final product

43
Q

What is the term for an extra-chromosomal circular piece of DNA that can replicate independently of the chromosome

A

a plasmid

44
Q

What are plasmids/episomes found in E.coli

A

F factor and R plasmids

45
Q

Is an episome/plasmid essential to the host cell

A

no, it can either replication autonomously (F+ cell) or integrate into the chromosome (Hfr)

46
Q

What occurs in transaction

A

bacteriophages attack the host bacterial cell, take up DNA of the host, and donate it to other host cells during infection efforts

47
Q

What is a cotransuctant

A

when two genes are close on the original chromosome and both are taken up by the virus and inputted into a new host (2 genes transducted)

Mbg 2040 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions