Origin & Diversity of Eukaryotes Flashcards
What did Carolus Linnaeus bring to the field of biology?
A hierarchical system of classification.
Out of bacteria, archaea, and eukarya, which are most closely related?
Eukarya & archaea. They have a closer common ancestor.
What is the definition of a “derived trait”?
A trait shared by a group of organisms but not found in their ancestor.
What is the phenomenon called where a derived trait is shared by a group and used as evidence of common ancestry?
“Synapomorphy”
When did multicellular organisms first start appearing?
After the first eukaryotes.
How many years ago did eukaryotes evolve?
1.5 billion years ago.
What is endosymbiosis theory?
That proteobacterium were taken up by eukaryotic cells to function symbiotically: the cell supplies pyruvate & O2, and the bacterium (mitochondria) provides ATP.
Name 3 pieces of evidence for the endosymbiosis theory.
- There is still a double cell membrane around the mitochondria
- Genes in mitochondria match bacterial genes
- Mitochondria (&chloroplasts) reproduce by binary fission independent of the cell!
What are protists?
All eukarya aside from fungi, animals, and land plants.
Where are we most likely to find protists?
In water.
Give a gross description of what is in the “unikonta” group and what is it the “bikonta” group.
Unikonta: animals, fungi, ameoba
Bikonta: plants etc.
How do amoebas move?
Via pseudopods (like feet) and cytoplasmic streaming.
What is a “test”?
A hard outer shell of a cell, some amoebas have tests.
How do amoebas get nourishment?
Phagocytosis
What do we need to know about “excavates”?
They are eukaryotes that used to have mitochondria, but don’t anymore. Mitochondrial DNA was integrated into the excavates nuclear DNA.
There is a type of organism that has no mitochondria that causes beaver fever, what type is this?
Diplomonads & Parabasalids (excavates),
What is characteristic of diplomonads & parabasalids?
They are unicellular, flagellated, and symbionts.
What was the endosymbiosis event that happened in the ancestor of “plantae”?
Took up a cyanobacterium (releases a lot of oxygen)
What kind of “-otroph” are green algae, and why?
Photoautotrophs. They use light to perform photosynthesis.
Which type of algae, red or green, can be unicellular?
Green.
What are some advantages of red algae?
They can use different light wavelengths for their photosynthesis.
What is the defining feature of alveolates?
They have cellulose in their cell walls and have alveoli.
What group has more than one nuclei, and how many does it have?
Ciliates; 2 types of nucleus: Micro & macro.
Are ciliates unicellular or multicellular? Where do they live?
They are unicellular and live in water.
What protects ciliates?
A protein pellicle
What group has an oral groove, a gullet, and an anal pore?
Ciliates.
What are apicomplexans? Give 3 characteristics.
- Unicellular
- Obligatorily parasitic & requires two hosts
- Cause of malaria (the #1 infectious disease)
What are at least 3 characteristics of dinoflagellates?
- 2 flagella
- photoautotrophic or heterotrophic
- Produce accesory pigments (gold-brown) for marine life
- Unicellular
Why are dinoflagellates dangerous?
They accumulate in biological tissue and release neurotoxins that are paralytic (obviously bad if ingested by vertebrates)
What group are brown algae, oomycetes, & diatoms a part of? and what are its defining characteristics?
Stramenopiles which have 2 unequal flagella, one with hairs.
What group are ciliates, dinoflagellates, and apicomplexa a part of?
Alveolata
How do brown algae grow, and why are they important?
They are photoautotrophs like the other algae, they are large and multicellular, grow quickly and form kelp forests. They are buoyant and provide habitats for many animals.
What type of stramenopiles are commonly used in toothpaste, metal polish, and pool filters? They are also an important part of phytoplankton.
Diatoms.
Which group within the stramenopiles used to be classified as a fungi? Describe it.
Oomycetes because they are filamentous and can be decomposers or parasites. They’re not though, they have cell walls with cellulose.
