UNIT II A- BAFPAVH Flashcards

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1
Q

Proposed by Carl Woese

A

Phylogenetic relationship

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2
Q

Phylogenetic relationship

A

Provides information on shared ancestry but
not necessarily on how organisms are similar
or different

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3
Q

evolutionary history and relationship of an

organism or group of an organisms

A

phylogeny

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4
Q

phylogeny

A

another such as which organisms thought to
have evolved from which species it is closely
related to

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5
Q

bacteria

A

single-celled organisms
- lack organelles, such as chloroplast and
mitochondria
- do not have true nucleus found in eukaryotic
cells
- a double stranded DNA that is continuous
and circular is located in a nucleoid

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6
Q

an irregular-shaped region that

does not have a nuclear membrane

A

Nucleoid

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7
Q

Bacterial cell membrane and cell wall is made

of

A

peptidoglycan

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8
Q

cell membrane+ cell wall

A

cell envelope

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9
Q

Binary fission

A

-bacterial reproduction
splitting of a bacterial cell after
reaching a certain size

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10
Q

bacterial reproduction. sexual/ asexual?

A

reproduce asexually hence the two
daughter cells, result from the binary fission,
have the same DNA as the parent cell

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11
Q

horizontal gene transfer or
transformation, conjugation and
transduction

A

bacterial exchange of genetic

material among one another

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12
Q

bacterial shape: Coccus: define and examples.

A
  • spherical/ovoid in shape
  • some remain attached after binary fission
    even forming separate cells
    examples: Streptococci – cocci in chains
  • Staphylococci – clusters of multiple
    cocci
  • Tetrads – square arrangements of
    four cocci
  • Sarcinae – cubes of eight cocci
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13
Q

bacterial shape: bacillus: define and examples.

A

-Rod-shaped bacteria
- Can be solitary or arranged together
Example:
o Diplobacilli – 2 bacilli arranged next
to each other
o Streptobacilli – chains of bacilli

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14
Q

bacterial shape: spiral: define and examples.

A
Spiral in shape
Example:
o Spirillum - thick, tough spirals
o Spirochetes – thin, flexible spirals
o Vibrious – comma-shaped rods with 
a small twist
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15
Q

State other bacterial shape.

A
  • Filamentous – long and thin
  • Square
  • Star
  • Stalk
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16
Q

what makes gram staining of bacteria possible?

A

cell wall

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17
Q

define gram staining

A
  • A method of staining bacteria involving
    crystal violet dye, iodine, and the
    counterstain safranine
  • Used for general identification of bacteria or
    detect the presence of certain bacteria
  • Cannot be used to identify bacteria in the
    species level
  • Can be used for grouping bacteria, gram-positive or gram-negative
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18
Q

Appearance of gram-positive bacteria and why?

A

Violet – due to the thick
cell wall that trapped the crystal violet iodine
complex

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19
Q

Appearance of gram-negative bacteria and why?

A
appear red due to 
the thin cell wall not 
holding the violet iodine 
complex but can hold 
safranine
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20
Q
Selectively permeable barrier, 
mechanical boundary of cell, 
nutrient and waste transport, 
location of many metabolic 
processes (respiration, 
photosynthesis), detection of 
environmental cues for 
chemotaxis
A

Plasma

membrane

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21
Q

Gas

vacuole

A

An inclusion that provides
buoyancy for floating in aquatic
environments

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22
Q

Ribosomes

A

Protein synthesis

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23
Q

Storage of carbon, phosphate,

and other substances

A

Inclusions

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24
Q

Localization of genetic material

DNA

A

Nucleoid

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25
Q
In typical gram-negative 
bacteria, contains hydrolytic
enzymes and binding proteins for 
nutrient processing and uptake
In typical gram-positive bacteria, 
may be smaller or absent
A

Periplasmic

space

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26
Q

Cell wall

A

Protection from osmotic stress,

helps maintain cell shape

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27
Q

Capsules
and slime
layers

A

Resistance to phagocytosis,

adherence to surfaces

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28
Q

Fimbriae

and pili

A

Attachment to surfaces, bacterial
conjugation and transformation,
twitching and gliding motility

29
Q

Swimming and swarming motility

A

Flagella

30
Q

Endospore

A

Survival under harsh

environmental conditions

31
Q

Archaea

A
delineated from Eukarya, 
Eubacteria.
-Lack a nucleus and consist of the 
extremophiles or ‘ancient’ bacteria (e.g. 
methanogens, thermophiles, halophiles)
32
Q

arkhaios

A

primitive

33
Q

Examples of members of archaea

A
• Pyrolobus fumarii - holds the upper 
temperature limit for life at 113 °C and 
found living in hydrothermal vents
• Picrophillus – isolated from acidic soils 
in Japan; most acid-tolerant organisms; 
known capable of growth at around pH 0
• Methanogens – produce methane gas 
as a metabolic by-product and found in 
anaerobic environment such as in 
marshes, hot springs, and animal guts
34
Q

Common Characteristics of Archaea

A

• Presence of tRNA and rRNA
• Absence of peptidoglycan cell walls;
replacement by largely proteinaceous coat
• Occurrence of ether-linked lipids built from
phytanyl chains in extreme environments
(Bacteria has esther-linked lipids)

35
Q

Fungi

A
  • eukaryotic, non-vascular, non-motile and
    heterotrophic organisms
  • may be unicellular or filamentous
  • reproduce by means of spores
  • exhibit the phenomenon of alternation of
    generation
  • lack chlorophyll and hence cannot perform
    photosynthesis
  • store their food in the form of starch
  • Biosynthesis of chitin occurs in fungi.
  • nuclei are very small.
  • fungi have no embryonic stage; develop
    from the spores
  • mode of reproduction is sexual or asexual
  • fungi are parasitic and can infect the host
  • produce a chemical called pheromone
    which leads to sexual reproduction in fungi
36
Q

Examples of fungi

A

mushrooms, moulds, yeast

37
Q

Alternation of

Generations/Metagenesis/Heterogenesis

A
  • important characteristic of fungi
  • asexual phase of the life of an organism
  • has 2 generations which are often
    morphologically or chromosomally distinct
38
Q

Fungi classification: Mode of Nutrition: Saprophytic

A

feeding on dead organic
substances
Examples: Rhizopus, Penicillium
and Aspergillus

39
Q

Fungi classification: Mode of Nutrition: Parasitic

A
living on other living organisms 
(plants or animals); absorb
nutrients from their host
Examples: Taphrina and 
Puccinia
40
Q

Fungi classification: Mode of Nutrition: Symbiotic

A
interdependent relationship 
association with other species in 
which both are mutually benefited
Examples: Lichens (algae 
synthesize carbs & fungi provides 
shelter) and mycorrhiza
41
Q

Fungi classification: Spore formation: Zygomycetes

A
formed by the fusion of two 
different cells
sexual spores – zygospores
asexual spores –
sporangiospores
The hyphae are without the 
septa
42
Q

Fungi classification: Spore formation: Ascomycetes

A
sac fungi; coprophilous (live 
on dung), decomposers, 
parasitic or saprophytic
sexual spores - ascospores 
Asexual reproduction –
conidiospores
Example: Saccharomyces
43
Q

Fungi classification: Spore formation: Basidiomycetes

A
Mushrooms are the most 
commonly found 
basidiomycetes and mostly 
live
as parasites
Sexual reproduction occurs 
by basidiospores
Asexual reproduction
occurs by conidia, budding or 
fragmentation
Example: Agaricus
44
Q

Fungi classification: Spore formation: Deuteromycetes

A
imperfect fungi-do not follow 
the regular reproduction 
cycle
do not reproduce sexually 
Asexual reproduction by 
conidia
Example: Trichoderma.
45
Q

Fungi classification: Reproduction:

Vegetative

A

By budding, fission and

fragmentation

46
Q

Fungi classification: Reproduction:

Asexual

A

-Anamorph
-This takes place with the help of
spores called conidia or
zoospores or
sporangiospores

47
Q

Fungi classification: Reproduction:

Sexual

A

-Teleomorph
-ascospores, basidiospores, and
oospores

48
Q

Protozoa

A
  • eukaryotic, unicellular microorganisms
    which lack cell wall
  • do not have cell wall but some possess a
    flexible layer called pellicle, a rigid shell of
    inorganic materials outside the cell
    membrane
  • move by locomotor organelles or by a
    gliding mechanism
  • have heterotrophic mode of nutrition
49
Q

Protozoan forms

A

Free-living forms - ingest particulates, such as
bacteria, yeast and algae
Parasitic forms - body fluids of their hosts
- reproduce primarily by asexual means,
although in some groups sexual modes also
occur

50
Q

Protozoa classification: Sarcodina

A
Motility: streaming of 
ectoplasm, producing 
protoplasmic projections called 
pseudopodia (false feet) 
Examples: Free-living form like 
Amoeba proteus* and parasitic 
form like Entamoeba histolytica*
51
Q

Protozoa classification: Mastigophora

A
Locomotion: one or more 
whip-like, thin structures called 
flagella
Examples:
Free-living forms like Euglena
viridis*, Cercomonas 
longicauda*, Heteronema acus*
Parasitic forms like 
Trichomonas vaginalis, 
Trypanosoma gambiense*, 
Giardia lamblia*
52
Q

Protozoa classification: Ciliophora

A
Locomotion: cilia, short 
hairlike projections whose 
synchronous beating propels 
the organism
Examples:
Free-living forms like 
Paramecium caudatum*,Stentor polymorpha*, Vorticella 
campanula*
Parasitic form like Balantidium 
coli*
53
Q

Protozoa classification: Sporozoa

A
do not have locomotor 
organelles in their mature stage
however, in immature form, they 
exhibit some type of movement;
All the members of this group 
are parasites.
Examples: Plasmodium, the 
malarial parasites of animals 
and human beings.
54
Q

algae

A

belongs to Protista
- a group of predominantly aquatic,
photosynthetic organisms of the kingdom
Protista
can photosynthesize like plants
- possess specialized structures and cell
organelles like centrioles and flagella, found
only in animals
either unicellular or multicellular organisms
- lack a well-defined body; structures like
roots, stems or leaves are absent
- found where there is adequate moisture
- Reproduction: asexual and sexual forms
- Asexual reproduction: spore formation
- free-living; some can form a symbiotic
relationship with other organisms

55
Q

Types of Algae:

Red Algae

A

-Rhodophyta
-Distinctive species found in
marine and freshwater
ecosystems; has chlorophyll a
but lack chlorophyll b or beta-carotene
-Pigments responsible for red
coloration: phycocyanin and
phycoerythrin

56
Q

Types of Algae:

Green Algae

A
Large informal grouping of 
algae having the primary 
photosynthetic pigments, 
chlorophyll a and b, and 
auxiliary pigments like betacarotene; can have symbiotic 
relationships with other 
organisms; members are 
uni/multicellular, colonial, and 
flagellates
Example: Spirogyra, Ulothrix, & 
Volvox
57
Q

Why are Blue-green Algae/Cyanobacteria not algae?

A
  • they are prokaryotes hence not an algae
  • lives in moist or aquatic environments
  • obtains energy through photosynthesis
  • fixes nitrogen in the soil
    Example: Nostoc, and Anabaena
58
Q

Viruses

A
  • Infectious, acellular pathogens
  • Obligate intracellular parasites with host and
    cell-type specificity
  • DNA or RNA genome (never both)
  • Genome is surrounded by a protein capsid
    and, in some cases, a phospholipid
    membrane studded with viral glycoproteins
  • Lack genes for many products needed for
    successful reproduction, requiring
    exploitation of host-cell genomes to
    reproduce
  • Have living (can mutate) and non-living
    characteristics (acellular – no cellular
    organelles)
  • Don’t grow and divide; new viral
    components are synthesized within the
    infected host cell
  • Vast majority of viruses have RNA genomes
    DNA virus – has DNA
    RNA virus – has RNA
    Plant viruses – have single-strand RNA
    genome
    Bacteriophages – have double-stranded DNA
    genome
    Example:
    • Coronavirus
    • Bacteriophage – a virus that infects a
    bacteria; bacteria-eater
59
Q

Viral Replication Process

A
  • Begins when a virus infects its host
  • Touching to the host cell, penetrating the
    cell wall/membrane
  • The virus genome is uncoated from the
    protein and injected into the host
  • The viral genome hijacks the host cells’
    machinery forcing it to replicate the viral
    genome and produce viral proteins to make
    new capsids
  • the viral particles are assembled into new
    viruses
  • New viruses burst out of the cell in the host
    cell during the process of lysis which kills the
    host cells
  • Some viruses take a portion of the host
    membrane during the lysis process to form
    an envelope around the capsid
60
Q

Helminths

A
Not a group of microorganisms but are 
included in studying microbiology
- Parasitic worms that feed on a living host to 
gain nourishment and protection while 
causing poor nutrient absorption 
- Cause weakness and disease to the host
- These worms and larvae live in the small 
bowel and are referred to as intestinal 
parasites
- Nematodes or roundworms
- Trematodes, which includes flukes or 
flatworms
- Cestodes or tapeworms
- Monogenans, also members of the flatworm 
phylum
- Share similar morphology
- Multicellular organisms that are visible to the 
naked eye
The worms are usually caught when 
treading on contaminated soil in warm, 
humid countries that have poor sanitation 
and hygiene
- Can grow up to 13ml in length
- Can penetrate human skin
61
Q

Features of Helminths:
Trematodes /
flatworms

A

flat, leaf-shaped and

unsegmented; hermaphroditic

62
Q

Features of Helminths:

Nematodes

A

cylindrical and have lips, teeth
and dentary plates; either male
or female

63
Q

Features of Helminths:
Cestodes or
tapeworm

A

segmented and hermaphroditic;
have a sucker and a projecting,
hooked rostellum

64
Q

Diseases caused by Helminths: Hookworm

disease

A
common worm infestation in 
the developing countries
Cause: Ancylostoma 
duodenale or Necator 
americanus
Illness lead to anemia and 
malnutrition
65
Q

Diseases caused by Helminths: Dracunculiasis

A
Cause: ginny worm, 
Dracunculus medinensis
transmitted through
contaminated water; lies 
burrowed within skin causes 
severe inflammatory 
reactions
66
Q

Diseases caused by Helminths: Loiasis or
African eye
worm disease

A
Cause: filaria Loa loa worm
contracted through Deer fly or 
Mango fly bites and the adult 
worms move through 
subcutaneous tissue towards 
the subconjunctiva of the eye
Illness: red, itchy swelling in 
the skin “Calabar swelling”
67
Q

Diseases caused by Helminths: Cysticercosis

A
Cause: tapeworm Taenia 
solium
Symptoms are not present for 
a year but painless bumps 
develop in the skin and 
muscles or cause 
neurological problems
68
Q

Diseases caused by Helminths: Echinococcosis

A
Cause: Echinococcus tapeworms
liver is usually affected first, 
followed by the lungs and 
brain; liver disease may 
cause abdominal pain and 
jaundice; lung disease leads 
to breathlessness and 
coughing