Protist Party
(Protists)
(Protists)
Definition of a protist
Any eukaryote that is not a plant, animal, or fungi
The most direct ancestors of land plants.
Green algae
Approximately how far back in time does the fossil record extend?
a. 3.5 million years
b. 5.0 million years
c. 3.5 billion years
d. 5.0 billion years
c. 3.5 billion years
What are the structural features all cells have?
plasma membrane, genetic material, ribosomes
The function of stomata in land plants
Able to open and close to allow gas exchange and decrease water loss.
What are the three types of locomotive diversity amongst protists and how they are different from one another?
Cilia: tiny hairs that allow the cell to move in a wave-like motion
Pseudopodia: Projections of the cell membrane that allow for movement
Flagella: hair-like structure that extends from part of the eukaryote to help them “swim”
Plant reproductive structure that allows sperm to be transported in the absence of water.
Pollen
What is the principle of parsimony?
The scientific principle that things are usually connected or behave in the simplest or most economical way, especially with reference to alternative evolutionary pathways.
In prokaryotes new mutations accumulate quickly in populations, while in eukaryotes new mutations accumulate much more slowly. The primary reasons for this are what?
Prokaryotes have short generation times and large population sizes.
The stage in alternation of generations that is diploid and what it produces, as well as the stage that is haploid and what it produces.
Diploid: Sporophyte, spores
Haploid: Gametophyte, gametes
Why it was adaptive for the larger host cell to keep the engulfed cell alive rather than digesting it according to the endosymbiotic theory?
The engulfed cell provided the host cell with adenosine triphosphate (ATP)
Why the first land plants are speculated to have a low, sprawling growth habit.
No structural support to stand up straight in air.
What major patterns of life can be observed across life's history?
1. character change
2. splitting events
3. stasis
4. extinctions
5. adaptive radiations
What are the themes in diversity of prokaryotes?
1. morphological
2. genetic recombination/mutation
3. METABOLIC DIVERSITY
A particular species of protist has obtained a chloroplast via secondary endosymbiosis. You know this because the chloroplasts _____.
Chloroplast from secondary endosymbiosis have three or four membranes
Two morphological innovations of protists and why they were adaptive.
Compartmentalization of organelles: separate incompatible chemical reactions, make reactions more efficient, etc.
Multicellularity: allowed for growth and specialization of certain cells
Larger size variation: more specialization and better competition
Structures for support and protection: cell walls & hard external shells
Two structural features that terrestrial plants evolved that helped reduce their risk of drying out (and explain how they prevent drying)
Cuticle: waxy layer that reduces water loss through tissues
Stomata: Cells that close openings to pores to reduce water loss
Sporopollenin: Covers and protects spores
Gametangia, seeds: reduce water loss through protection of reproductive cells
Put the following events from the history of life in relative order (1 = earliest, 5 = most recent)(1pt)
____Origin of prokaryotes
____Origin of animal life
____Origin of eukaryotes
____Origin of multicellularity
1 Origin of prokaryotes
4 Origin of animal life
2 Origin of eukaryotes
3 Origin of multicellularity
If prokaryotes reproduce asexually through binary fission, and the resulting daughter cells are genetically identical, where does the genetic variation necessary for evolution come from?
Mutation, gene duplication, gene flow/genetic recombination (transduction, transformation, conjunction)
Definition of endosymbiosis, as well as all five pieces of evidence that support the theory of endosymbiosis.
Endosymbiosis is the theory that organelles in eukaryotic cells (mitochondria and chloroplasts) originated from the cell engulfing a prokaryote/bacteria.
1. Similar size as bacteria
2. Contains circular DNA
3. Have own ribosomes to make proteins
4. Replicate by binary fission
5. Double membranes
One difference between bacteria and protists in all of these categories: Cells, replication, and energy/nutrition
Cells: Bacteria are prokaryotes and unicellular, protists are eukaryotes and uni or multicellular
Replication: Bacteria asexually through binary fission, protists sexually or asexually and includes alternation of generations
Energy: Bacteria have more metabolic diversity than plants, which are primarily autotrophs.
Two evolutionary novelties of gymnosperms and why they were adaptive.
“Naked” seeds - seeds not enclosed within an ovary like angiosperms. Seeds allow the embryo to remain dormant until conditions are favorable for growth.
Cones - Allows for wind dispersal. Reduces dependence on water for reproduction. Protects the naked seeds.
Make a phylogenetic tree with 5 species (A, B, C, D, and E) A and D are sister taxa. B and E are sister taxa. C is the next closest relative to A, D, B, and E. What is the outgroup? What would you circle/include to identify a monophyletic group of 4 species?
C is the outgroup.
Circle A, D, B, and E and the node of their common ancestor.
Compare and contrast Eukaryotes with Prokaryotes.
Eukaryotes have a nucleus, while prokaryotes do not. Eukaryotes have multiple linear chromosomes, while prokaryotes have one circular chromosome. All prokaryotes are unicellular, while Eukaryotes can be both unicellular or multicellular. Both eukaryotes and prokaryotes have ribosomes, a plasma membrane, and genetic material.
What are the four reasons why prokaryotes are important? BONUS: can you list examples and how to identify them?
1. ecosystem function: Cyanobacteria (photosynthesis, 75% of Earth's O2)
2. symbiont: Firmicutes (Metabolism in human gut, firm="strong"; cuti="skin," gram-positive)
3. Biomedical: Actinobacteria (used to produce antibiotics, gram-positive)
4. Research: Proteobacteria (used in biotechnology, example: E. coli used for gene cloning)