Protista

Question 1

What are Protists?

Answer 1

Eukaryotes that are not an animal, plant, or fungi.

• very diverse with few common characters
• paraphyletic group

Question 2

Polytomy

Answer 2

• pitchfork with 3 brances is not a 3 way split

- means we do not understand the split and need more data.

Question 3

Unifying Traits

Answer 3

1. Membrane bound organelles and nucleus
2. Sexual and Asexual reproduction(meiosis and mitosis)
3. Usually unicellular
   
   • some colonial or multicellular
4. Usually aquatic

Question 4

Protists are an “____”

Answer 4

entire world in a drop of water.

Question 5

Diverse Traits

Answer 5

Protists groups are as distantly related from each other as animals are from plants.

1. Range in nutritional mode.
2. Range in locomotion
3. Endosymbiosis

Question 6

Diverse Traits:

Range in nutritional modes

Answer 6

1. Plant-like Protists(autotrophs, can photosynthesize)
   
   • Algae, diatoms, dinoflagellates
2. Fungus-like Protists(absorptive heterotrophs; exoenzymes; decomposers)
   
   • Exudes enzymes that digest from outside and then suck up the goop.
   • slime molds, water molds
3. Animal-like Protists(ingestive heterotrophs)
   
   • eating other organisms
   • Everything not in 1 or 2.

Question 7

Diverse Traits:

Range in Locomotion

Answer 7

1. Pseudopods
   
   • extension of cytoplasm to location then cytoplasmic streaming for rest of body to come to it.
2. Flagella
   
   • tail like - 1 or 2
3. Cillia
   
   • 100-1000s of hair like apendages
4. Sessile
   
   • no self movement. Move by water currents

Question 8

Diverse Traits:

Endosymbiosis

Answer 8

Original endosymbiotic event leads to the evolution of eukaryotes from prokaryotes, creating the mitochondrion. Subsequent endosymbiotic events occurred in some lineages that give rise to other organelles like chloroplats.

1. Primary endosymbiosis – eukaryotic heterotroph engulfs photosynthetic
   cyanobacterium. Bacterium membrane lost, forms organelle (i.e. chloroplast). This lineage give rise to the red and green algae.
2. Secondary endosymbiosis – In both the red and green algae lineages, multiple independent endosymbiotic events occur.

Original -> primamry -> secondary
- 3 events