MICROPARA 5 Flashcards
are referred to as protists because
they are in the Kingdom Protista.
Algae and protozoa
(a thickened cell membrane)
pellicle
(a light-sensing organelle, also known as an eyespot),
a stigma
Most algal cell walls
contain
cellulose
are tiny, usually unicellular algae that live in
both freshwater and seawater
Diatoms
have been investigated for use as drug delivery systems in
medicine, and their potential use in nanotechnology has
drawn great interest.
Diatoms
are microscopic, unicellular, flagellated,
often photosynthetic algae.
Dinoflagellates
are responsible for
what are known as “red tides
Dinoflagellates
include many
different genera, all of which can be found in pond water
Green algae
The agar used as a solidifying agent in laboratory
culture media is a complex polysaccharide derived from a
red marine alga
One genus of algae is a very rare cause of
human infections
(Prototheca)
Most protozoa are
unicellular (single-celled)
Most protozoa are unicellular (single-celled), ranging in
length from
3 to 2,000 µm
Protozoa have no ___ and, therefore,
cannot make their own food by photosynthesis.
chlorophyll
cells are more
animal-like than plantlike.
Protozoal
Some
flagellates and ciliates ingest food through a primitive
mouth or opening, called a
cytostome.
A typical protozoan life cycle consists of two stages:
the
trophozoite stage and the cyst stage
(common pond water ciliates) possess both a pellicle
(thickened cell membrane) and a cytostome.
Paramecium spp.
Some pond
water protozoa (such as amebae and Paramecium) contain
an organelle called a ___, which pumps
water out of the cell.
contractile vacuole
The is the
motile, feeding, dividing stage in a protozoan life cycle
trophozoite
Amebae (or amebas) move by means of cytoplasmic
extensions called
pseudopodia
Protozoa are sometimes classified taxonomically by their
mode of locomotion.
is the nonmotile, dormant, survival stage.
cyst
Many parasitic protozoa are pathogens,
such as those that cause
malaria, giardiasis, African
sleeping sickness, and amebic dysentery
An ameba ingests a food particle (e.g.,
a yeast or bacterial cell) by surrounding the particle with
pseudopodia, which then fuse together; this process is
known as
phagocytosis.
When
fluids are ingested in a similar manner, the process is
known as _
pinocytosis.
Cilia exhibit an _
motion
oarlike
are the most complex of all
protozoa.
Ciliates
, transmitted by the tsetse fly, causes
African sleeping sickness in humans
Trypanosoma brucei
A pathogenic ciliate, causes
dysentery in underdeveloped countries.
It is
usually transmitted to humans from drinking water that has
been contaminated by swine feces
Balantidium coli,
is the only
ciliated protozoan that causes disease in humans
Balantidium coli,
Flagella exhibit a motion
wavelike
cruzi
causes American trypanosomiasi
Trypanosoma
causes persistent sexually
transmitted infections of the male and
female genital tracts;
Trichomonas vaginalis
Nonmotile protozoa—protozoa lacking pseudopodia,
flagella, or cilia—are classified together in a category
called
sporozoa.
causes a
persistent diarrheal disease
Giardia intestinalis
The most important sporozoan pathogens
are the that cause malaria in many areas
of the world.
Plasmodium spp.
“garbage disposers” of nature—the “vultures” of the
microbial world
Fungi
Malarial parasites are transmitted by female
___mosquitoes, which become infected when they
take a blood meal from a person infected with malaria.
Anopheles
It is estimated that ___ are the most diverse group of
organism on the earth
fungi
The study of fungi is
called
mycology
saprophytes, their main source of food
is dead and decaying organic matter.
fungi
One way that fungi differ from plants and
algae is that they are ___ they have no
chlorophyll or other photosynthetic pigments
not photosynthetic;
Fungal cell
walls do contain a polysaccharide called
chitin
Yeasts and microsporidia are ))___whereas moulds
are
unicellular, multicellular
Although many fungi are unicellular others grow as filaments called ____hyphae which intertwine to form a mass called a ___
, hyphae
, mycelium
contain multinucleated cytoplasm (described as being
coenocytic).
Aseptate hyphae
fungal cells can
reproduce by
budding, hyphal extension, or the formation
of spores.
There are two general categories of fungal
spores:
sexual spores and asexual spores.
—spores are produced by the fusion of two
gametes
Sexual
__ spores are formed in many different
ways, but not by the fusion of gametes
Asexual
the reproductive structure arises from a fungal component
called a conidiophore, then the spores are referred to as
conidia
If the
reproductive structure is formed within a sac-like structure
called a sporangium, then the asexual form is referred to as
a sporangiospore
a sporangiospore
The two phyla known as
“lower fungi” are the
Zygomycotina
the Chytridiomycotina (
include the common bread moulds and other fungi that
cause food spoilage.
Zygomycotina
The two phyla known as
“higher fungi” are the
Ascomycotina
Basidiomycotina
Some fungi classification schemes contain a phylum
called
Deuteromycotina
which are not
considered to be true fungi by some taxonomists, live in
water (“water moulds”) and soil
Chytridiomycotina,
include some yeasts like Cryptococcus, some fungi that
cause skin infections and plant diseases, and the large
“fleshy fungi” that live in the woods
Basidiomycotina
include certain yeasts like Candida species, moulds like
Aspergillus and Penicillium, and some fungi that cause
plant diseases
Ascomycotina
Contained
in this phylum are fungi in which the sexual form of the
organism has not been discovered or that the organisms
have lost the ability to perform sexual reproduction.
Deuteromycotina
Deuteromycota). This phylum is
sometimes referred to as the
Fungi Imperfecti.
Yeasts are eukaryotic, single-celled (unicellular) organisms
that lack
mycelia.
They usually
reproduce by budding (Fig. 5-12), but occasionally do so by
a type of spore formation.
Yeasts
The common yeast
(“baker’s yeast”) ferments sugar
to alcohol under anaerobic conditions.
Saccharomyces cerevisiae
are examples of yeasts
that cause human infections.
C. albicans and C. neoformans
A few fungi, including some human pathogens, can live
either as yeasts or as moulds, depending on growth
conditions
Dimorphic Fungi.
A new inclusion in the Kingdom Eumycota are a diverse
group of organisms called the . THEY are obligate intracellular parasitic fungi. For many years,
they were classified with the protozoa.
microsporidia.
Microsporidia,they possess a
unique organelle called the
polar filament
polar filament
The large fungi that are encountered in forests, such as
mushrooms, toadstools, puffballs, and bracket fungi, are
collectively referred to as
fleshy fungi
A variety of yeasts and moulds cause human infections
(known as
mycoses
Fungal infections are known as
mycoses
are fungal infections of the outermost
areas of the human body, such as hair, fingernails, toenails,
and the dead, outermost layers of the skin
Superficial mycoses
A group of moulds,
collectively referred to as dermatophytes, cause tinea
infections, which are often referred to as
“ringworm”
infections.
(athlete’s foot)
tinea pedis
, tinea
unguium
fingernails
tinea capitis
scalp
tinea barbae
(face and neck)
(trunk of the
body
tinea corporis
are fungal infections of
the dermis and underlying tissues
Subcutaneous mycoses
They appear as colored, often
circular patches on tree trunks and rocks.
LICHENS
it was thought that a represents a combination of
two organisms—an alga (or a cyanobacterium) and a
filamentous fungus—living together in such a close
relationship that they appear to be one organism.
LICHENS
—a
relationship in which all parties benefit
mutualism
which are found in soil and on rotting logs,
have both fungal and protozoal characteristics and have
recently been transferred out of the Kingdom Fungi and
placed in the Kingdom Protozoa;
SLIME MOULDS
