Ch. 19 Protists Flashcards
Often used informally to describe the many phyla of animal like protists
Protozoa
A temporary extension of cytoplasm and plasma membrane that helps protozoa move and feed
Pseudopod
Fake foot
Pseudopod
Short, hairlike structures that cover some/all of the cell surface to help the organism swim and capture food
Cilia
Photosynthetic plantlike protists
Algae
A large group of single celled organisms that swim with the aid of one or two flagella
Euglenoids
Flexible coat like covering on euglenoid’s cell surface which allows the cell to change shape and in some species helps the organisms to creep across solid surfaces like a worm
Pellicle
Can produce light through internal chemical reactions
Bioluminescent
Eukaryotic organisms that have both fungus like and animal like traits
Slime molds
Fungus like protists that are made up of branching strands of cells
Water molds
Why are protists grouped together?m
They share some features with animals, plants, and fungi but lack one or more traits that would place them in these 3 kingdoms.
Describe protists.
- may be single/ multi celled
- reproduce asexually or sexually or both
How are protists categorized?
Based on how they get their food
Describe animal like protists.
Heterotrophs/single celled (unlike animals)/ lack chloroplasts
Describe Plant like protists.
Autotrophs through photosynthesis; may have roots, stems, or leaves; and may be single celled, colonial, or multicellular
Animal like protists Ex.
Oxytricha
Plant like protists Ex.
Pediastrum
Fungus like protists Ex.
Slime molds
Describe fungus like protists.
Decompose dead organisms/ (unlike fungi) can move
A eukaryote that is not an animal, plant, or fungus
Protists
What key difference between animal like protists and animals?
all animal like protists are unicellular while all are multicellular
Where are the flagella in zooflagellates?
Their flagella are extensions of cytoplasm made bundles of microtubules enclosed by a plasma membrane.
Whose flagella is bigger- prokaryote’s or zooflagellate’s?
Zooflagellate’s
Why amoebas form pseudopods?
To move
How do pseudopods form?
Forms when cell cytoplasm flows outward to form a bulge which spreads, anchors itself to the surface its on, and pulls the rest of cell toward it (NEEDS ENERGY)
How do amoebas get food?
Through ingestion through the process if phagocytosis
Explain phagocytosis in amoebas.
It surrounds the food with its pseudopods, and its outer membrane forms a food vacuole. Digestive enzymes enter the food vacuole from the surrounding cytoplasm, and digestion takes place.
Explain amoebas.
Live in fresh water, salt water, and soil
Majority are free living, but some are parasites
Most are microscopic
Explain zooflagellates.
All are heterotrophs that can eat prokaryotes that feed on dissolved organic matter
Some are pathogens or live inside other organisms in mutualism
What are shorter than flagella and found in greater number?
Cilia
Explain ciliates.
Some are parasites that cause diseases
Most are free living and found in fresh water.
Example of a free living ciliates in fresh water.
Paramecium
Explain zooflagellate Trypansoma (sleeping disease).
Transmitted by tstee fly bite and causes coma and death
Explain Malaria.
From Anopheles mosquito bite
Symptoms: fever, vomiting, severely affects kidney and liver function
Leads to coma and death
Mosquitos developed resistance to anti malarial drugs
Explain zooflagellate Giardia.
Causes intestinal disease
Become infected by drinking water contaminated with feces of infected animals
What is the difference plants and plant like protists?
Plant like protists don’t have roots, stems, leaves, specialized tissues, or the same reproductive structures
Plant like protists can be be single or multi celled while all plants are multicellular
Explain plant like protists.
Many single celled ones are free living aquatic organisms that together with photosynthetic bacteria are phytoplankton
Several species of single celled ones live in colonies (Ex. Volvex)
Can be multi celled
Some species eat other organisms through photosynthesis
Ex. Of multicellular plant like protists.
Seaweeds and kelps
In the past single celled organisms combined into multicellular organisms such as….
Volvex
How did single celled algae become multi celled?m
Individual cells in colonies that were efficient at certain tasks became more specialized over time and became more dependent on each other and led to multicellular forms
Where do most plant like protists live?
In freshwater and marine ecosystems, but some live in deserts and tundra.
What do most plant like protists have at some point in their life?
Flagellum
How are plant like protists grouped into several phyla?
Based on their photosynthetic pigments and cell wall membrane
Explain plant like euglenoids.
Most found in freshwater, some in ocean environments
How are plant like photosynthetic euglenoids green?
Comes from 2 different chlorophyll pigments (chlorophyll a and b)
All photosynthetic organisms have what?
Chlorophyll a
Chlorophyll b is only in what?
Only in green algae and plants
Explain dinoflagellates.
Singled celled
90% marine plankton
Some are freshwater and some are snow
About half of all marine dinoflagellates photosynthesize
How do dinoflagellates move?
They have 2 flagella.
One extends from the rear cell and propels it forward and the other is ribbonlike strand that circles the cell in a groove along its body and allows the cell to turn over and change direction
The combination of 2 flagella cause it to turn in a spiral as it moves forward
Example of a bioluminescent organisms.
Noctiluca
What can dinoflagellates do and cause?
Can help build coral reefs through their mutualistic relationship with coral and cause red tides through their toxins
Tiny celled algae covered in delicately patterned glass shells
Diatoms
What do diatoms’ shells serve as?
An external skeleton to help the cell hold its rigid shape
What do diatoms play a critical role in?
The uptake of carbon dioxide and the production of half of the world’s oxygen
Explain diatoms.
May be freshwater or marine
Many species are phytoplankton
Other live clinging to rocks, plants, soil, and animals ( crustaceans, turtles, and whales)
Why are diatoms well preserved?
Because of their glassy mineralized shells
What are the industrial uses for diatom skeletons?
Ingredient in scrubbing products due their rough texture
Explain green algae.
May be found in water and land but most are aquatic
Multicellular and have chlorophyll a and b
Plants/ green algae have accessory pigments called carotenoids
What are accessory pigments?
Capture light energy and transfer it to chlorophyll during photosynthesis
What suggests that algae were early ancestors if plants?
Have cell walls made if cellulose and store food in cells as starch
Example of brown algae.
Underwater kelp forests
Explain Brown algae.
Multicellular
Can be extremely large
Photosynthetic with chlorophyll c like diatoms
Explain red algae.
Most found in ocean and few in freshwater
Use chlorophyll a for photosynthesis but get their color from pigment phycoerythrin
How can red algae grow in deeper depth?
Because their red pigments allow it to absorb blue light reaching deepest in the ocean
How can all algae reproduce?
Asexually
Multicellular algae can do what?
Fragment
What are the similarities between fungus like protists and fungi?
Both can decompose and have similar reproductive structures/ cycles
How are fungus like protists and fungi different?
Fungus like protists can move
What can slime molds be divided into?
Plasmodial/ cellular slime molds
Example of plasmodial slime molds.
Dog vomit slime molds
What are plasmodial slime molds like most of their life?
A single mass of cytoplasm that is actually a large single cell with many nuclei called a plasmodium
How do plasmodial slime molds move?
Like a giant amoeba creeping over the ground as it absorbs bacteria and nutrients from decaying matter
What do plasmodial slime molds do when food and moisture are in short supply?
They stop growing and develop non moving reproductive structures that produce spores
Explain cellular slime molds.
Common in soil
Each spore released by it becomes a single amoeba like cell
What do cellular slime molds do when food is scarce?
Individual cells can release chemical signals that cause the cells to swarm together and form a slug like body that moves as 1 organism celled a pseudoplasmodium (fake plasmodium) because each cel, is independent (cell membranes don’t fuse).
Explain water molds.
Common in freshwater habitats
Many are decomposers
Some are parasites of plants and fish
Ex. Of water mold parasite
Phytophthora infestations causes disease potato blight
Explain potato blight.
Outbreak in Ireland from 1845-1849
Destroyed almost all of potato crops
1 million people died of starvation called Great Potato Famine
