2. WHAT ARE PROTISTS?
• Protists are eukaryotes which means their cells have a nucleus and
other membrane bound organelles
• Most, but not all, protists are single-celled. Other than these
features, they have very little in common
• Protists are neither animals nor plants, not fungi
• Protists come in many different shapes. Some are very simple
similar to prokaryotes and some are more complex than these
simple singled-celled protists
• Protists were probably the first eukaryotes to evolve
4. WHY PROTISTS ARE CALLED "JUNK
DRAWER"?
• Although Ernst Haeckel set up the Protista in 1866, this kingdom was not accepted by the
scientific world until the 1960’s
• These unique organism can be so different from each other that sometimes Protista is called
"junk drawer kingdom"
• Just like a junk drawer, which contain items that don’t fit into any other category, this kingdom
contain the eukaryotes that cannot be put into any other kingdom
• Therefore, protists can seem very different from one another
5. GENERAL CHARACTERISTICS
• Protists are very diverse and have few traits in
common
• Most are single-celled organism, but some are
multicellular (e.g Algae), and others lives in
colonies
• Some produces own food, others eat other
organisms or decaying matter
• Some can control own movement, others cannot
6. GENERAL CHARACTERISTICS
• Eukaryotes (have a nucleus), but are less complex then others
eukaryotic organisms
• Don’t have specialized tissues
• Most have mitochondria
• They can be parasites
• They all prefer aquatic or moist environments
8. 1. PLANT-LIKE PROTISTS
• Plant-like protists are called algae. They include single-celled
diatoms and multi-cellular seawed.
• Like plants, algae, contains chlorophyll and make food by
photosynthesis. Therefore, these plant-like protists are also called
photo-synthetic protists.
• These big guys can grow upto 2 feet (60cm) in height, but they are
still one single cell.
• Example: Dinoflagellates, Euglenoid, Diatom
9. 2. ANIMAL-LIKE PROTISTS
They are also called protozoans,a protist with animal like
characteristics . Protozoans are heterotrophs, unicellular, mostly are
mobile. Proto means “first” and zoia means “animal”.
Because they were consider primitive or first animal, they cannot
make their own foods. They are classified by movements. These
protists are very small, measuring only about 0.01-0.5mm.
Example: Amoeba, Flagellates, Ciliates, Sporozoans
10. 3. FUNGI-LIKE PROTISTS
Fungi-like protists are molds, Molds are absorptive feeders, found on
decaying organic matter,. They resemble fungi and reproduce with spores
as fungi do. These organisms lack chlorophyll and absorb food through
cell walls. Lack the chitin cell walls of true fungi. Have centrioles unlike
true fungi who lack them. They are heterotrophs in nature. They are
smaller than a few centimeters, but can reach
UpTo 30 sq. meters.
Example: Slime Molds, Water Molds
11. ASEXUAL REPRODUCTION
Asexual reproduction requires one parent and produces offspring that are
genetically identical to that parent.
In addition to the convenience of cell reproduction, asexual reproduction can
occur more frequently and produce rapid population growth.
Because of this, asexual reproduction is a primary method protists use to
reproduce.
Different types of asexual reproduction occurs in protists:
12. TYPES OF ASEXUAL REPRODUCTION
1. Binary fission
It occurs when a single protists divide its nucleus and then divides itself into
two separate organisms.
2. Multiple fission
It is similar to binary fission, except the nucleus can divide and form many
daughter nuclei. The organism will then divide into separate organisms for each
nuclei that has been created.
3. Budding
it occurs when a new organism grows from the body of parent organism. The
new organism may separate from the parent or remains attached, forming colonies.
13. SEXUAL REPRODUCTION
Sexual reproduction in protists required two parent organism.
Both organism contribute genetic material to the offspring. The
benefit of sexual reproduction is that it creates this genetic
variability. Sexual reproduction techniques that occur in protists
are conjugation and alternation of generation. Conjugation
occurs when two protists of the same species come together
and form a temporary union. They exchange genetic material
during this union. when the two protists separate, they
genetically different from the original organisms.
15. DISEASES CAUSED BY PROTISTS
• Most protist diseases in humans are caused by
protozoa. Protozoa make humans sick when they
become human protists. Trypanosoma protozoa causes
Chagas diseases and sleeping sickness. Plasmodium
protozoa causes malaria.
• These protists diseases are described as:
16. TRYPANOSOMA PROTAZOA
Members of the genus trypanosoma are flagellate
protozoa that cause sleeping sickness, which is
common in Africa. They also cause Chagas
disease, which is common in south America.
The parasites are spread by insects vectors.
Trypanosoma parasite enter a person's blood
when the vector bites. Then they spread to
other tissues and organs. The diseases may be
fatal without medical treatment. Trypanosoma
parasite is spread by an insect commonly
called the “kissing bug”. A bite from this bug
could be the kiss of death.
17. PLASMODIUM PROTOZOA
Plasmodium protozoa cause malaria. The
parasites are spread by a mosquito vector.
Parasites enters the host blood through
the bite of infected mosquito. The
parasites infect the hosts red blood cell,
causing symptoms such as fever, joint
pain, anemia and fatigue. Malaria is
common in tropical and subtropical
climates through out the world. Infact,
malaria is one of the common infectious
diseases on the planet. It is very serious
diseases that kills several million people
each year, mostly children.
18. PROTISTS AND HUMANS
• Protists can be beneficial to humans as well as the ecosystem as a whole
• They can also be tiny terrors causing diseases in humans and livestock and costing money for
diseases treatment and lose of livestock
Protists can be beneficial as:-
• Some protists live in the digestive tracta of humans and cattle and may aid in digestion
• They are used as basis of food chains
19. PROTISTS AND HUMANS
• Diatoms are used in reflective parts, filter and abrasives
• Large multicellular algae is eaten (sushi and food emulsifiers)
• They produce a lot of oxygen that used in breathe
• Many are deterivores , such as , help breakdown wastes and recycle nutrients
