Protists Flashcards
What is an example of cooperation between eukaryotes(i.e mutualism/symbiosis)
Healthy coral - animal(coral) + photosynthesized(zooxanthellae, a dinoflagellate)
What is coral bleaching? What are the four causes of coral bleaching?
Healthy coral: Coral and algae depend on each other to survive
Stressed coral: if stressed, algae leaves the coral
Bleached coral: Coral is left bleached and vulnerable
What causes coral bleaching
1. Change in ocean temp
2. Runoff and pollution
3. overexposure to sunlight
4. extreme low tides
The first eukaryote evolved from an ancient prokaryote. How do evolutionary changes occur?
- Random mutation causes a new trait
- That new trait makes the individual(and its offspring) better able to survive and reproduce`
How did the eukaryotic cell arise?
- the origin of a flexible cell surface
- the origin of a more complex cytoskeleton
- the origin of a nuclear envelope
- the appearance of digestive vesicles
- the endosymbiotic acquisition of certain organelles
the origin of a flexible cell surface
the first step toward the eukaryotic condition
- Loss of the cell wall
Result
- Flexible cell membrane
Consequences
- Infolding increases surface area for cell to exchange materials with the environment, allowing
- A larger cell size
- More rapid metabolism
- Ability to take in large particles from environment(endocytosis)
Infolding of membrane allowed for the formation of ribosome studded internal membranes
the origin of a more complex cytoskeleton
Some prokaryotes have a rudimentary cytoskeleton
Consequences
- Allows the now much larger cell to manage changes in its shape
- Allows distribution of daughter chromosomes
the origin of a nuclear envelope
Prokaryotic DNA is attached tot he cell membrane. Infolding of plasma membrane attached to a chromosome led to the formation of the nuclear envelope
the appearance of digestive vesicles
ability to phagocytose(engulf other cells)
crucial for endosymbiosis
What is the endosymbiotic acquisition of mitochondria and chloroplasts?
Infoldings in the plasma membrane of an ancestral prokaryote gave rise to end-membrane components, including a nucleus and endoplasmic reticulum
In a first endosymbiotic event, the ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria
in a second endosymbiotic event, the early eukaryote consumed photosynthetic bacteria that evolved into chloroplasts
Endosymbiosis
Mitochondria and chloroplasts were derived from bacterial lineages through endosymbiosis
Entire bacteria were engulfed by eukaryotes and evolved into these particular organelles
Did all organelles arise via endosymbiosis?
chloroplasts, endoplasmic reticulum, etc.
Cyanobacteria are prokaryotes that convert sunlight to chemical energy via _________(1). Since they are gram negative, they have a thin layer of _______(2) and an extra _____(3) outside of their cell wall.
photosynthesis
peptidoglycan
membrane
Primary endosymbiosis
a gram negative cyanobacteria(composed of an inner and outer layer, in addition to a peptidoglycan in its cell wall) is engulfed by a eukaryotic cell.
Over evolution, the peptidoglycan layer has been lost
green and red algae, as well as land plants, get their chloroplasts from primary endosymbiosis
Secondary symbiosis
eukaryotic cell takes up a photosynethic eukaryote which evolves into a chloroplast. Some groups have retained traces of the engulfed cell while others have not. In some group, you can observe four membranes around the chloroplast.
how many membranes does the chloroplast have in the euglenoid? What about the plant cell
plant cell: 2
euglenoid: 3
Eukaryotes are a
monophyletic group
include euglenoids, fungi, plants, protists insects, us, yeast
The term protist is used to describe any eukaryote that is NOT
a plant, animal, or fungus
Protists are
paraphyletic group
Most protists are
unicellular and microscopic(microbe)
microbial eukaryotes is a synonym for unicellular protists
What are the advantages of a eukaryotic cell over a prokaryotic cell/
- Compartmentalization allows separation of potentially harmful substances from rest of cell
compartmentalization allows greater regulation of metabolism
compartmentalization allow greater specialization of cells(including option for multicellularity)
What are plankton? what are two types of plankton? Are these protists?
Plankton: free floating aquatic organisms
phytoplankton: photosynthetic plankton
zooplankton: cannot photosynthesize
yes they are protists
What is algae? Is it a protist?
- anything that is not a plant that can photosynthesize
- photosynthetic protists
- includes phytoplankton and multicellular photosynthetic protists
What are autotrophs?
get energy from sunlight or chemical sources
What are heterotrophs
get energy from eating other organisms
