week 6 - protists

Question 1

protists

Answer 1

• A polyphyletic (and very messy) group
  o Not a single common ancestor
   Which is why there is lots of variation
• Loosely defined as “unicellular eukaryotes without a cell wall”, but no shared defining feature
  o There are exceptions
• Protozoa is sometimes used interchangeably but, sometimes as a subgroup (the most ‘animal-like’ protists

Question 2

protists features

Answer 2

• No unifying morphological or biochemical feature for all protists
• But within the protisits, different groups are frequently characterised by a unique shared character

Question 3

protists example:
Kinetoplastids

Answer 3

o In the Alveolates group
o Have a single large mitochondrion with a mass of DNA inside called a kinetoplast
o Can account for up to 30% of the genome

Question 4

protists example:
- oomycetes

Answer 4

o In the stramenoplies group
o Fungal characteristics
 Heterotroph
 Filmentous morphology (water molds)
* Similar morphology to fungi
o But also plant characteristics
 Cellulose cell wall
 Some have cholorplasts (phototrophic)

Question 5

protists example:
- oomycetes
examples

Answer 5

potato blight

Phytophthora sojae

saprolegnia