Post on 28-May-2020
Kingdom: Protista
Protists are unicellular
organisms that have a
nucleus.
Similar to Bacteria
Unicellular One of the first groups of living things on
Earth. (1.5-2.1 billion years ago.)
Microscopic
Can cause disease. Can be parasites
Difference from Bacteria
Has a nucleus.
Live in watery environment.
Generally live as individual cells.
Protists vary greatly in appearance and
function.
3 Categories
I. Animal-like Protists.
II. Plant-like Protists.
III. Fungus-like Protists.
I. Animal-like Protists
Protozoan means “First Animal”.
Cells contain a nucleus.
Cells lack a cell wall.
They are heterotrophs.
Most can move on their own.
They are so named because many species behave like tiny animals—specifically, they hunt and gather other microbes as food.
4 Groups of Animal-like Protists All protozoa digest their food in stomach-
like compartments called vacuoles <vac-you-ohls>. As they chow down, they make and give off nitrogen, which is an element that plants and other higher creatures can use.
Protozoa range in size from 1/5,000 to 1/50 of an inch (5 to 500 µm) in diameter.
1. Sarcodines (Amoeboids)
2. Ciliates
3. Flagellates
4. Sporozoans
1. Sarcodines (Amoeboids)
The Amoeboids and are found in the phylum Rhizopoda
Extensions of the cell membrane and cytoplasm.
Pseudopods are used for movement and to capture food.
Are split into to group those with shells and those without, testate amoebae, which have a shell-like covering, and the naked amoebae, which don't have this covering.
These shells form limestone, marble and chalk.
One type:
Most familiar Sarcodine.
Pseudopods:
Blob shaped.
Contractile Vacuoles: controls amount of water inside
Food Vacuole: where food is digested.
Split Personality
Amebas reproduce by dividing into two new cells (binary fission).
Amebas can respond to their environment.
They are sensitive to light and some chemicals.
2. Ciliates
Ciliates from the phylum Ciliophora. These are generally the largest protozoa.
Have cilia on the outside of their cells.
Tiny hair-like projections used for movement, to gather food and as feelers.
Type: Paramecium
Pellicle: tough outer wall.
Slipper shaped
Oral groove: like the mouth
Gullet: holds food.
Food Vacuole: digests food.
Anal Pore: removes wastes
2 Contractile Vacuoles
2 Nuclei
Reproduces by either binary fission or conjugation.
3. Flagellates (Zooflagellates)
Have a Flagellum: a long whip-like structure used for movement.
Many live in animals
Symbiosis a close relationship, at least one benefits.
Mutualism: when both partners benefit.
Flagellates con’t Flagellates are of the
phylum Zoomastigina.
the smallest of the protoza.
Flagellates use their flagella to move.
It is a flagellate in the intestines of termites which enable them to eat wood. Both organisms benefit
4. Sporozoans The last of the Protozoans come from the
phylum, Sporozoa
All Sporozans are parasites.
They feed on cells and body fluids.
Form from Spores (tiny reproductive cells).
Pass from one host to another.
Pass from ticks, mosquitoes or other
animals to humans.
II. Plant-like Protists
(Algae)
Unicellular and Multicellular
Colonies (groups of unicellular protists)
Can move on their own
Autotrophs: make their own food from simple
materials using light energy (photosynthesis).
70% of the Earth’s oxygen is produced by Plant-
like Protists!
Pigments: chemicals that produce color
There are three unicellular phyla of algae:
Phylum Euglenophyta (Eugelnoids)
Phylum Bacillariophyta (Diatoms)
Phylum Dinoflagellata (Dinoflagellates)
There are three multicellular phyla of algae which
are classified by color:
Red Algae
Green Algae
Brown Algae
1. Euglenoids
Green
Unicellular
Live in fresh water
Autotrophs, but can be heterotrophs under certain conditions by ingesting food from the surrounding water.
Flagella
Eyespot: sensitive to light.
Chloroplasts
Are plant like and animal like.
2. Diatoms
Unicellular 10,000 living species.
Aquatic
Glass like cell wall made of silica
Photoautotrophs
Make up a large portion oh phytoplankton, a source of Earth’s oxygen.
3. Dinoflagellates
Unicellular Cell walls are like
plates of armor.
Two flagella
Spins when it moves. Colorful (pigments)
Can glow in the dark.
Causes Red Tide
Red Algae Multicellular seaweeds
Rhodophyta are red seaweeds.
They are found in warm or cold marine environments along coast lines in deeper water.
They absorb green, violet, and blue light waves. These light waves are able to penetrate below 100 meters.
Green Algae The last of the
multicellular algae are the green algae
from the Phylum
Chlorophyta. Most are unicellular
Some form colonies
Few are multicellular
Can live in fresh and salt water and on land in damp places.
Very closely related to green plants.
Brown Algae Commonly called seaweed
Can contain brown, green, yellow, orange and black pigments.
Attach to rocks
Have air bladders
They are found in cool saltwater along rocky coasts.
Phylum Phaeophyta is made up of the brown algae.
Giant Kelp are the largest and most complex brown algae. They have hold fasts and air bladders. Giant Kelp can be 100 meters long!
III. Fungus-like Protists Heterotrophs
Have cell walls.
Many have flagella and are able to move at some point in their lives.
Three types: Slime Molds, Water & Downy Molds
Reproduce with Spores (tiny cell that is able to grow into a new organism)
Fungus-like protists, Myxomycota and Oomycota are decomposers.
Phylum Myxomycota are made up of plasmodial slime molds.
Phylum Oomycota is made up of water molds and downy molds.
Water & Downy Molds Live in water or moist
places.
Tiny threads that look like fuzz.
Attack food crops
Caused the Irish Potato Famine.
Water molds from the Phylum Oomycota are classified as protists because they have flagellated reproductive cells.
Downy mildews parasitize plants and are decomposers in freshwater ecosystems.
Slime Molds
Reproduce by Fruiting Bodies:
The Fruiting Bodies contain Spores.
At first they look like ameba, then later they look like mold.
Live on moist shady places.
Feed on bacteria and other microorganisms.
Slime molds have traits like both fungi and animals. During good times, they live as independent, amoeba-like cells, dining on fungi and bacteria. But if conditions become uncomfortable—not enough food available, the temperature isn't right, etc.—individual cells begin gathering together to form a single structure. The new communal structure produces a slimy covering and is called a slug because it so closely resembles the animal you sometimes see gliding across sidewalks. The slug oozes toward light. When the communal cells sense that they've come across more food or better conditions, the slug stops