Classification, Structure and Replication of Microorgamisms

Question 1

which two species of “microorganisms” don’t count as organisms

Answer 1

viruses and prions

Question 2

which 3 microorganisms have their own kingdoms

Answer 2

bacteria protista and fungi

Question 3

what is the structure of a standard bacteria

Answer 3

nucelus has no membranę, circular and free floating
flagella for locomotion
pili and fimbriae - aid adhesion to host cells in gram negative
capsule or slime layer - polysaccharide layer to protect from phagocytosis
endospores - metabolically inert form of bacteria - protects them in times of stress

Question 4

what are the 4 types of flagella

Answer 4

montrichous - single at back
lophotrikhous - multiple at back
amphitrichiois - one either side
peritrichious - lots all over

Question 5

what is the india ink test

Answer 5

slime capsule absorbs it and shows up as dark

capsule excludes india ink when died

Question 6

what are the categories when classifying bacteria

Answer 6

gram stain 
shape 
endospores 
atmospheric preference 
fastidiousness 
key enzymes

Question 7

what is the difference between gram positive and gram negative

Answer 7

takes up crystal violet and turns purple (contains peptidoglycan)

negative has little peptidoglycan which counter stains pink

Question 8

when classifying bacteria what does atmospheric preference mean

Answer 8

aerobic, anaerobic, facultative (both)
microaerophiles (prefer reduced O2)
capnophiles (prefer increased O2)

Question 9

what are he 4 types of bacterial replication

Answer 9

binary fission
conjugation
transformation
transduction

Question 10

what happens during binary fission

Answer 10

produce identical daughter cells
produce FtsZ ring which contracts to produce two cells
exponential process
(this process is a target for antibacterial agents)

Question 11

what is doubling time

Answer 11

time take for one cell to split into two

Question 12

what happens during conjugation

Answer 12

genetic variation

transfer of transposable elements such as circular plasmids - sex plus forms and plasmid is now in each daughter cells

Question 13

what happens during transformation

Answer 13

picking up genetic material from environment - more variation - allows trasnfer of antibiotic resistance

Question 14

what happens during transduction

Answer 14

transfer of generic information via viral vector

introduce eugenic diversity

Question 15

what characteristic is shared by all fungi

Answer 15

eukaryotic and cell wall made of chitin

Question 16

what are the two types of fungus

Answer 16

yeast

mould (filamentous)

Question 17

what is the structure of yeasts

Answer 17

grow and multiple by budding - most common is thrush by C albicans
single eukaryotic, bud scar, nucleus, mitochondria, vacuole, lipid granules

Question 18

what is the structure of moulds

Answer 18

grow in mats of tiny filaments known as hyphae that from mycelia
eg mouldy bread - penicillin spp

Question 19

what can hyphae be divided into

Answer 19

septa

Question 20

describe the process of fungal replication

Answer 20

asexual or sexual
asexual - non genetic diversity using spores undergoing mitosis

sexual - plasmogamy (haploid) goes to karyogamy (nuclei fuse to from diploid zygote) then undergoes meiosis (haploid spores formed) - produces unique mycelium

Question 21

what are two types of parasites

Answer 21

protozoa - unicellular eukaryotic

helminths (animalia) - worms

Question 22

what are protozoa classified by and give examples

Answer 22

morphology and locomotion 
flagellates 
amoebae - change shape 
ciliates - move due to cilia 
apicxomplexa or sporozoa

Question 23

how do protozoa replication

Answer 23

asexually (fission)
but can sexually exchange information via conjugation (not with reproduction)
occurs in host, may require more than one host to complete life cycle
may from hardy cysts

Question 24

what are viruses

Answer 24

obligate intracellular parasite (require host)

made of nucleic acid core wrapped in protein coat (some have envelope (lipid) and other are naked)

Question 25

what are the steps in a virus life cycle

Answer 25

attachment/penetration - virus attaches via protein on its surface and enters via endocytosis

uncaring - genome released from capsid

early viral proteins produced - these allow replication and regulation

genome replication - DNA -> mRNA

late viral proteins produced - structural proteins of virus occurs in ribosomes

virion assembly - from nucelocaspid, viral proteins concentrated at caspid

Question 26

what are the two types of virion release

Answer 26

lytic - bursts cells - kills host

lysogenic - bacteriophage, does not damage host as integrates DNA into hosts and replicates

Question 27

where does replication occur for RNA viruses

Answer 27

primarily in the cytoplasm - non reliant on host

Question 28

where does replication occur for retroviruses

Answer 28

uses host replication system eg HIV (integration)

Question 29

how do we classify viruses

Answer 29

RNA (positive or negative sense) or DNA (double or singel stranded)
symmetry or dimensions of caspid
presence of an envelope

Question 30

what are prions

Answer 30

misfiled proteins - no genetic material
can be inherited, spread or occur spontaneously
aggregate and cause misfiling of native proteins = chain reaction affecting brain

Question 31

what are 3 examples of prions diseases

Answer 31

CJD
BSE (mad cow disease)
Scrapie - from cows and sheep