Post on 17-Dec-2015
20-1 Kingdom Protista
• Any organism that isn’t a plant, animal, fungus, or prokaryote
• Has a nucleus & membrane bound organelles
• Most are unicellular, some multi-cellular
• First eukaryotic organisms on Earth
• Can only grow & reproduce in wet environments
• Found in Plankton- important food source for others
• Feed mainly on bacteria
Lynn Margulis- hypothesis that protists came from mitochondria & chloroplasts of prokaryotes that began to live inside larger cells
Sub-divided by the way they get nutrition, not based on evolutionary history
20-2 Protozoans-animal-like
A. Zooflagellates- swim using flagella
Found in lakes & streams or inside other organisms
Absorb nutrients from decaying material
Sexual & asexual reproduction
Ex: Trichonympha- live in gut of termite
Trypanosoma- African sleeping sickness, destroys red blood cells, spread by tsetse fly
B. Sarcodines- use pseudopods- temporary projections of cytoplasm (oozing blob)
Have food vacuole-stores food
Unfavorable conditions- they become a cyst
Ex: Amoebas- binary fission, big blobs
Foraminiferans & Radiolarianshard shells of calcium carbonate, food
source for marine environment, when they die>build up chalk on ocean bottom & cliffs
Cliffs of Dover- England http://www.youtube.com/watch?v=U7CoBXzJLWM
C. Ciliates- use cilia, fresh & salt waterEx: Paramecium- most common,
freshwater
Parts: Pellicle- outer membraneTrichocysts- defense structures
Macronucleus- multiple copies of genes used for everyday
Micronucleus- reserve copy of all genes
Gullet/oral groove-sweep algae & bacteria to make food vacuole
Anal pore- removes waste
Contractile vacuole- expels excess water
Ciliate reproduction
Most are asexual
Conjugation- exchange genetic material with others
Line up side by side & swap a pair of micronuclei
NO new individuals > Not reproduction, just a sexual process to exchange genes & create genetic diversity
D. Sporozoans- do not move on their own
Parasites
Sporozoites- transmitted through fluids
Ex: Plasmodium- causes Malaria
Carried by Anopheles mosquito, infects liver, bursts red blood cells
African Sleeping Sickness http://animal.discovery.com/videos/monsters-inside-me-african-sleeping-sickness.html
Monsters Inside Me: Brain Eating Amoeba http://animal.discovery.com/videos/monsters-inside-me-the-brain-eating-amoeba.html
20-3 Plant-like Protists
Have chlorophyll > photosynthesis
Low amounts of light in sea, so they have adapted and can use more than just red light. Also, use accessory pigments (carotenoids, xanthophylls)
Unicellular
1. Euglena- have 2 flagella, no cell wall
Great swimmers, freshwater
Eyespot- helps find light
Can also live as heterotrophs
Asexual
Pellicle- outer membrane, allows to live in mud
2. Dinoflagellates- 2 flagella wrapped around them Asexual
½ photosynthetic, ½ heterotrophs
Luminescent- give off light
No histones for DNA to wind around
http://www.youtube.com/watch?v=eSROHwGaLCg
3. Chrysophytes- yellow green algae
Gold colored chloroplasts
Store food in the form of oil
Sexual & asexual
Form thread like colonies
4. Diatoms- cell walls contain silicon (glass)
Extras Phytoplankton- does 70% of all the photosynthesis on Earth
Symbiosis- lives in coral reef
Algal Blooms- love growing in sewage Clean up waste but deplete water of oxygen, so kill off fish
Ex: red tides http://www.youtube.com/watch?v=VKx-B0zLXu8
20-4 Multicellular Plant-like protists
5. Red Algae- Rhodophyta- red plants
Can live at great depths- great photosynthesizers
Found from polar to tropical waters
Lack flagella
Stabalize coral reefs- coralline algae has calcium carbonate in cell walls
6. Brown Algae- PhaeophytaChlorophyll a & c
Largest and most complex
Giant Kelp- over 60 m long
Contain a holdfast- anchors to bottom or rocks
http://www.youtube.com/watch?v=ZQb9ZFWfNZE
Reproduction of Algae Alternation of Generations- switch between diploid &
haploid stages
Chlamydomonas- mostly asexual- makes zoospores by mitosis But during unfavorable conditions- sexual, releases + & -
gametes (haploid) that pair together to make a zygote (diploid)
Grows thick protective wall and when conditions are right, becomes haploid again
Human uses for Algae
Food sources for oceans
Earth’s oxygen from photosynthesis
Sushi wraps, used to make ice cream, salad dressings, pudding, plastics, paints
20-5 Fungus-like Protists
Grow in damp areas
Absorb food through membranes
Have centrioles (fungi don’t)
Lack chitin cell walls
Slime Molds Forest floors
Cellular-cell membranes
Acrasiomycota Most of life is free-living
When conditions are bad > secretes chemical to form large colony with nearby cells
Colony migrates, makes fruiting body that produces spores
Water Molds- Oomycota
Feed on dead or decaying matter in water or on plants on land
Hyphae- cell walls of cellulose & motile spores Fungi don’t have
Asexual- Zoosporangia (spore cases)
Sexual- Antheridium- male nuclei, Oogonium- female nuclei
Facts
Important recyclers of organic material
Can be harmful- mildew, blights of grapes & tomatoes
1840’s- potato #1 food in Ireland
1845- Phytophora infestans = Great Potato Famine 1.5 million migrate to US
Potato Famine
Potato Famine
http://www.bing.com/videos/search?q=great+potato+famine&FORM=HDRSC3#view=detail&mid=C79162540736123451AEC79162540736123451AE
Protists
Protists
http://www.youtube.com/watch?v=-zsdYOgTbOk
Plant-like
http://www.youtube.com/watch?v=o5ESHXKGBvA
Summation video
https://www.youtube.com/watch?v=Ln69k7LyTsU