Topic 4 - Kingdom Protista

- eukaryotes:  have membrane-bound organelles.  The nucleus is the biggest organelle
-there are about 200 000 species in this kingdom
-most live in aquatic, marine or moist conditions
-very diverse - 3 groups: animal-like, plant-like and fungus-like

1.  Fungus-like
eg.  slime molds (nyálkagomba)
-saprotrophic
-multicellular
-share protist and fungal characteristics

2.  Animal-like
-Phylum Protozoa
-unicellular
- 200-300 times larger than most bacteria
- nutrition:  parasites, predators, saprotrophs
-grouped by type of locomotion
a) Non-motile
-parasites
-eg. malaria (váltóláz) caused by Plasmodium

The infected red blood cell is full of small purple dots (those are the protist!)

Image from: tolweb.org/images/Plasmodium/68071


b) Amoebas (állábuak)
-move and feed with pseudopods (false feet)

Image from: shs.westport.k12.ct.us/mjvl/biology/biohome.htm

-includes hundreds of species
-engulf food by flowing around it.  Watch this!
-marine or aquatic, some are parasitic (eg. dysentery/vérhas)
-some have shells (extend pseudopod through holes in shell) - important in calcareous rock formation

c) Flagellates (ostorosok)

-move with flagella

-some are predators, some are parasites (eg. Trypanosoma, which causes sleeping sickness)

Image from:  www.eden.rutgers.edu/chrmccoy/paraspring10.htm

d)  Ciliates (csillósok)

-covered with cilia, move by beating cilia

-have 2 kinds of nuclei:  macronucleus to control cell life functions and micronucleus (1 or more) for reproduction

eg.  Paramecium (papucsállatka)

Here is a malaria jigsaw puzzle!

Osmosis - the movement of water across a selectively permeable (or semi-permeable) membrane from an area with low solute concentration to an area of high solute concentration.  This process doesn't require energy.  Osmosis is important in biology because many biological membranes are semi-permeable and most cells have higher concentrations of solutes inside them than in surrounding freshwater.

From: www.goldiesroom.org/Note%20Packets/06%20Transport/00%20Transport-WHOLE.htm

If you want to see a video, try this.

We talked about this as it related to contractile vacuoles in Paramecium

Plant-like Protists

-can be unicellular or multicellular (include algae, which look like plants, but they have no real roots, stems or leaves! - more on this later!))

-are phototrophs, so they photosynthesize.  To do this they must have pigments (green, red, brown and yellow can be found!), which are found in chloroplasts (zöldszíntest)

-have cellulose cell walls

- the microscopic ones form phytoplankton (plankton that can photosynthesize)

You can listen to a short radio program about phytoplankton (general information, not related to the course specifically).  Scroll down on the page until you reach the section on Fading phytoplankton.

Classification
1.  Euglenophyta (ostorosmoszatok törzse)
-unicellular
-aquatic
-mixotrophs:  autotrophic in light (photosynthesizes since it has chlorophyll - green pigments - in chloroplasts), heterotrophic (hunters) in dark
-store food as starch (plant-like characteristic)
-no cell wall, have pellicle (animal-like protist characteristic)

eg.  Euglena viridis (zöld szemesostoros)

-the red eyespot detects light, the euglenoids move towards the light to be able to photosynthesize

-flagella allow for active movement

-cytopharynx (missing from this image, but in your notes) and contractile vacuole are animal-like protist characteristics

2.  Yellow Algae, aka Diatoms (sarga vagy kovamoszatok)

-unicellular

-autotrophs - chlorophyll (green) and carotenoids (yellow)

-marine and freshwater

-silica shells (kovapáncél) - like little round jewellery boxes, radially symmetrical

-used for abrasives in toothpastes and polishes, added to paint to make it sparkle

3.  Green Algae (zöldmoszatok)

-most diverse group:  about 7000 species

-major pigment is chlorophyll (green), but also contain carotenoids

-have cellulose cell wall and store starch (plant-like)

-primarily freshwater, but also marine and can even be found in moist soil, on trees, in snow and in the fur of sloths (lajhár)!!

-ancient ancestor of simplest plants

-unicellular and multicellular (thalloids)

4.  Red Algae (vörösmoszatok)
-marine
-most are multicellular with 3-D thalloid bodies
-contain chlorophyll (green), phycoerythrins (red) and phycobilins (blue)
-can survive up to 200m deep because can photosynthesize with just green, blue and violet light
- uses: food, agar and food thickener

5.  Brown Algae (barnamoszatok)
-about 1500 species
unicellular and multicellular
-almost all marine, found in cool areas
-don't grow deep than 25m
-contain chlorophyll (green) and fucoxanthin (brown)
-the largest and most complex in the group (60-100m tall) are the kelp.  They form kelp forests (important marine habitat) and are also used as food.

kelp forest

Reproduction in Algae
-both asexual and sexual
Asexual
-fragmentation (in filamentous algae)
-halving (diatoms)
-spores

when asexual and sexual alternate during a lifetime, it is referred to as the life cycle

Alternation of generations (nemzedékváltakozás)
-this includes both sexual and asexual stages

The gametes are haploid (n) - this means they only carry 1 copy of the genetic information.  When they fuse they form a diploid (2n) zygote, which now has 2 copies of the genetic information.  This grows into a sporophyte.  A halving division called meiosis occurs, which produces haploid spores.  These spores grown into gametophytes, which are also haploid.  Gametophytes produce gametes and the cycle begins again.