L11 - Classification, structure and replication of m/o

Question 1

what are the 3 main domains?

Answer 1

prokaryota

eukaryota

archaea

Question 2

what are the 5 main kingdoms?

Answer 2

Bacteria

protista

fungi

plantae

animalia

Question 3

describe a bacteria cell

Answer 3

• single cell organism
• lack membrane bound nucleus
• prokaryotes

[have a cell wall, cell membrane, sex pilus, flagellum,
fimbriae and capsule]

Question 4

what is the bacterial organ of locomotion?

Answer 4

flagella

Question 5

what does a monotrichous flagella look like?

Answer 5

one at the back

A

Question 6

what does a Lophotrichous flagella look like?

Answer 6

many at the back

B

Question 7

what does a Amphitrichous flagella look like?

Answer 7

one on either side of cell

C

Question 8

what does a Peritrichous flagella look like?

Answer 8

lots on either side

D

Question 9

what specialised structures to bacteria have to aid adhesion to host cells and colonisation?

Answer 9

Pili and fimbriae [Gram negative bacteria]

Question 10

what is the function of a bacteria’s capsule of slime layer?

Answer 10

Polysaccharide material protecting bacteria from phagocytosis, dessication,
immune attack, antibiotics

Question 11

what does the India ink test, test for?

Answer 11

• add India ink
• If it has a capsid, it will not be taken up (white)
• If it has a slime layer, it will be taken up (dark)

Question 12

what is biofilm?

Answer 12

Structure containing lots of bacteria adhering together to provide protection from
antibiotics

Question 13

what is an endospore?

Answer 13

An endospore is a dormant, tough, non-reproductive structure

• during a harsh environment they produced spores to allow them to survive for many years
• not active or able to reproduce
• when conditions are Bette they can return to the active form

Question 14

into what categories can you classify bacteria?

Answer 14

• gram stain
• cell shape
• endospore
• atmospheric preference
• fastidiousness
• key enzymes
• DNA

Question 15

what is gram stain used for?

Answer 15

Gram stain is used to identify if the bacteria is gram positive or
negative

Question 16

what colour does gram positive stain?

Answer 16

purple

crystal violet binds to the cell wall

Question 17

what colour does gram negative stain?

Answer 17

red

crystal violet doesn’t bind to the cell wall

Question 18

what does cocci refer to?

Answer 18

round shape

Question 19

what does coccus refer to?

Answer 19

one round bacteria

Question 20

what does diplococci refer to?

Answer 20

two round bacteria

Question 21

what does streptococci refer to?

Answer 21

multiple round bacteria

Question 22

what does bacilli refer to?

Answer 22

rod shaped

Question 23

what does bacillus refer to?

Answer 23

one rod bacteria

Question 24

what does diplobacilli refer to?

Answer 24

two rod bacteria

Question 25

what does streptobacilli refer to?

Answer 25

multiple rod bacteria

Question 26

what does coccobacillus refer to?

Answer 26

between round and rod

Question 27

what ways can bacteria replicate?

Answer 27

- binary fission - conjugation - transformation - transduction

Question 28

what is binary fission?

Answer 28

cells divide to give two identical daughter cells [asexual, creates new bacteria, but no exchange of genetic material]

Question 29

what is conjugation?

Answer 29

transfer of transposable elements [Creates no new bacteria, some genetic diversity.]

Question 30

what is transformation?

Answer 30

picking up genetic material from the environment [Creates no new bacteria, introduces some genetic diversity to the population.]

Question 31

what is transduction?

Answer 31

transfer of genetic information via a viral vector [Introduces some genetic diversity into a population.]

Question 32

which type of bacterial replication results in genetic diversity?

Answer 32

conjugation transformation transduction

Question 33

which type of bacterial replication results in new bacterium being made?

Answer 33

binary fission

Question 34

what is the name for transfer of genetic information via a viral vector?

Answer 34

transduction

Question 35

what is the name for picking up genetic material from the environment?

Answer 35

transformation

Question 36

with reference to binary fission, what is doubling time?

Answer 36

amount of time it takes for one cell to become 2 NB: bacteria have different doubling times - important consideration for antibiotic treatments

Question 37

which type of bacterial replication uses a sex pilus?

Answer 37

conjugation

Question 38

what is the process of binary fission?

Answer 38

- DNA replication - Cell elongation - Contraction of FtsZ ring - Cell wall synthesis and Cell division

Question 39

which bacterial replication process results in both bacteria having the plasmid?

Answer 39

conjugation

Question 40

what is the process of transduction?

Answer 40

o Attachment of the viral cell to the bacterial cell o Release of its DNA into the bacterial cell o Interaction with the chromosomal DNA of the bacterial cell o Breaking up of the DNA o Results in the proteins of the virus

Question 41

what domain are fungi?

Answer 41

eukaryotic

Question 42

what domain are bacteria?

Answer 42

prokaryota

Question 43

what is a fungi cell wall made of?

Answer 43

chitin [Structure of N–Acetylglucosamine - Structure is similar but it is different to plants (cellulose)]

Question 44

what is the most common yeast infection?

Answer 44

thrush caused by C. (candida) albicans

Question 45

what is thrush caused by?

Answer 45

fungi - C. (candida) albicans

Question 46

how do fungi replicate?

Answer 46

sexually asexually via spores

Question 47

which method of fungal replication results in genetic diversity?

Answer 47

sexually

Question 48

which method of fungal replication results in no genetic diversity?

Answer 48

germination of spores - Mitosis from mycelium (1n)

Question 49

what are the two types of parasite?

Answer 49

protozoa (protists) helminths (Animalia)

Question 50

what are the 4 types of protozoa?

Answer 50

● Flagellates – e.g. Giardia [flagella to move] ● Amoebae – e.g. Entamoeba [change its shape] ● Cilliates – e.g. Balantidium [cilia to move] ● Apicomplexa (or Sporozoa) – e.g. plasmodium

Question 51

how do protozoa replicate?

Answer 51

Reproduce asexually (fission)

Question 52

what are the components of a virus?

Answer 52

- nucleic acid - protein coat - envelope

Question 53

describe the viral life cycle?

Answer 53

1. attachment/penetration 2. uncaring 3. Early viral proteins produced 4. Genome replication 5. Late viral proteins produced 6. Virion assembly 7. Virion release

Question 54

during viral replication, how does the virus attach/penetrate a cell?

Answer 54

endocytosis direct membrane fusion

Question 55

with reference to the viral replication cycle, what is meant by the step uncaring?

Answer 55

● Genome is released from capsid (protein coat) during / after penetration ● Genetic material targeted to nucleus

Question 56

with reference to the viral replication cycle, how does a cell perform the final step of virion release?

Answer 56

lytic - bursts cell lysogenic

Question 57

how do retroviruses replicate?

Answer 57

➢ Unusual ➢ Reverse transcriptase converts RNA to DNA ➢ Integrated in host DNA (integrase) ➢ Uses host replication system [people are affected by this virus indefinitely]

Question 58

which characteristics do you use to classify a virus?

Answer 58

● Nature of the nucleic acid: RNA or DNA ● Symmetry of the capsid ● Presence or absence of an envelope ● Dimensions of the virion and capsid

Question 59

what classification of virus is the herpesvirus?

Answer 59

dsDNA

Question 60

what classification of virus is the parvovirus?

Answer 60

ssDNA

Question 61

what are prions?

Answer 61

➢ Misfolded protein ➢ Unlike viruses, no genetic material ➢ Can be inherited, spread via contaminated material or occur spontaneously ➢ Aggregate and cause misfolding of native proteins – chain reaction Examples: - Creutzfeldt-Jakob Disease - Bovine spongiform encephalopathy - Scrapie