Brainscape's Knowledge GenomeTM

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


See full index

Infection, immunity and repair > Origin and evolution > Flashcards

Origin and evolution Flashcards

1
Q

What is the origin of all living things?

A

LUCA

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

What did the LUCA form?

A

Bacteria

Archae

Eukaryotes

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

What are the two types of evidence for evolution?

A

Fossils

DNA and protein sequences

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

Since when have biofilms existed?

A

Since the origin of bacteria

Strange as bacteria have not evolved greater complexity

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

What is the difference between gram positive and gram negative bacteria?

A

Gram positive -> one membrane, on outer surface is thick coat of peptidoglycan

Gram negative -> two membranes, between membranes are molecules of peptidoglycan

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

Why is peptidoglycan essential for bacterial life?

A

Bacteria are stuffed with oncotic molecules

Puts turgor pressure on organism

Peptidoglycan prevents bacteria from bursting

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

How does Penicillin kill bacteria?

A

Penicillin weakens the peptidoglycan

Bacteria burst

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

How did LUCA form bacteria?

A

LUCA morphed into peptidoglycan containing cell

Primordial cell = cell with peptidoglycan containing wall

Evolution pushed the wall between two thin membranes or one thick wall

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

Do all bacteria contain peptidoglycan walls?

A

No

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

What are examples of a bacteria that does not contain a peptidoglycan cell wall?

A

Tenericutes - live on specialised niches like skin

Thermophiles - modified petidoglycan to overcome extreme conditions

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

What is endosymbiosis?

A

2 billion years ago non- and photosynthetic bacteria got into proto-eukaryotic cells

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

What did photosynthetic bacteria form?

A

Photosynthetic organelles in plant cells

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

What did non-photosynthetic bacteria form?

A

Mitochondria

Key for energy and apoptosis

Mitochondria benefits from being inside cells and cell benefits from having extra energy

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

What is neo-darwinism?

A

Modern take on Darwin’s theory of survival of the fittest

Neo-darwinism = mutations + genetic recombination

When plants and animals reproduce the offspring contains differences in DNA through genetic recombination

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

How are mutations selected for in Neo-Darwinism?

A

Mutations in DNA produce variations in proteins

Proteins can become favourable -> kept in gene pool, passed to offspring

Proteins can become unfavourable -> disappear from population

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

Why do bacteria have such low genetic recombination?

A

They reproduce clonally

17
Q

What is the mechanism in which bacteria can have genetic recombination?

A

Plasmids

Bacteriophages

Genomic islands

Horizontal gene transfer - responsible for 30% of genes in bacteria

18
Q

How does bacteria transfer DNA in order to allow for genetic recombination?

A

Naked DNA

19
Q

Mechanisms of horizontal gene transfer

A

Transformation

Conjugation

Transduction

20
Q

Describe the process of Transformation

A

Bacteria is taken up from environment via naked DNA and plasmids

21
Q

Describe the process of Conjugation

A

Some bacteria perform sex

Tube between two cells

DNA transfer from one cytoplasm to another

22
Q

Describe the process of Transduction

A

Bacteriophages - viruses infect bacteria

23
Q

How many genes are there in a genome of bacteria?

A

3000

24
Q

How many genes are there in a genome of a human?

A

19000

25
Q

What is the pan genome?

A

Number of genes accessible for strain of bacteria

26
Q

Does evolution happen at a constant rate?

A

Yes

27
Q

Is the rate at which bacteria mutate constant?

A

No

HGT might be constant however

28
Q

What is stress-induced mutagenesis?

A

Mutations can be enhanced if exposed to external stresses

29
Q

What is an example of stress-induced mutagenesis?

A

Antibiotics drives antibiotic resistance

Bacteria mutate faster to increase resistance to antibiotics

30
Q

How can plasmids be used to increase reisistance to antibiotics?

A

Bacteria can take up plasmids with antibiotic resistant genes

Makes organism into a resistant strain

31
Q

How did bacteria evolve from LUCA?

A

LUCA -> bacteria

Initially bacteria lived in anoxic environment

Liquid and air - no oxygen

Cyanobacteria started producing oxygen

Planet becomes toxic

100s years -> atm contains oxygen

Bacteria living under different conditions evolve to these

Infection, immunity and repair (52 decks)

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