The Origin And Diversification Of Eukaryotes Flashcards
What is the dichotomy of cells
Prokaryotes and eukaryotes
Which cell came first
Prokaryotes
What is something shown in the first slide that eukaryotic cells can do that prokaryotic can not?
A drastic change in shape to engulf another cell
Certain eukaryotic cells can do this because of a complex cytoskeleton
What does cytoskeleton mean
What is it made up of
Skeleton of the cell
It is a framework to keep things in place in the cell.
Continuously changing structure
It is a complex set of proteins 3 sets
Microtubials
Intermediate filaments
Microfilaments
When did eukaryotic cells come into existence
At least we About 1.8 bya based on fossil evidence
There was a variety of cell fossils at this time suggesting that the first eukaryotes must have come earlier
What happened about 1.8 to 1.3 bya for eukaryotes that is it’s on category
The initial eukaryotes and then diversification
All unicellular but developing cell types
1.3 bya to 750 mya
Appearance of novel feature or things that didn’t exist before
Evolution of eukaryotic photosynthesis
First sexual reproducing organisms
True complex multicellularity- not just multiple cells but multiple types doing different stuff - everything is still small however
From about 635 mya to present is where what happened to eukaryotes?
Animals plants and fungi came about
How did eukaryotic cells come to be
Based on cell theory
Eukaryotic cells came from prokaryotic cells that evolved
What is a differences in the name between eukaryotes and prokaryotes
Membrane bounded organelles and membrane bounded nucleons
Prokaryotes to eukaryote
An anaerobic Archean, didn’t not undergo aerobic respiration, was a free living cell eating other things didn’t have nucleus
Nucleor envelope evolved, the plasma membrane has envaginasions that fold towards the DNA rapping around nicleoid until it’s enclosed
The nucleus in a eukaryotic cell that explains how it came from prokaryotes based on the membrane
There is two membranes - the nucleor envelope is two phospholipid bilayer
And then the pinch off leads to eneoplamic reticulum
Endosymbiotic theory
For appearance of mitochondria and chloroplast
Engulfed bacterium survived being eaten and lived inside cell- endosymbiosis
This bacteria was capable of aerobic respiration
Phagocytosis
First mitochondria. - also are doubly membrane bounded. Outer membrane is like cell. Inner is like membrane of bacterium. Own DNA( linear chromosomes) in nucleus, mitochondrial ( circular chromosomes) DNA. Cell has ribosomes and then mitochondrial ribosomes. Mitochondria reproduce themselves through binary fusion
Now doing aerobic cellular respiration inside cell
Same thing happened with a photosynthetic bacterium leading to the chloroplast- this came later cause not all eukaryotes are photosynthetic
Phagocytosis
The process of a cell eating another cell
Rapping blasma membrane around the thing being engulfed - then the piece of plasma membrane encoded the thing(bacterium) engulfed
First mitochondria. - also are doubly membrane bounded. Outer membrane is like cell. Inner is like membrane of bacterium. Own DNA( linear chromosomes) in nucleus, mitochondrial ( circular chromosomes) DNA. Cell has ribosomes and then mitochondrial ribosomes. Mitochondria reproduce themselves through binary fusion
Now doing aerobic cellular respiration inside cell
Cereal endosymbiosis
Primary endosymbiosis leads to another secondary and multiple membranes of the plastid
Colonial life of eukaryotes lead to
Evolved to make cells stick together making it easier to survive
This lead to cell types to diversify and multicellular organisms to come into existence
All animals are
Multicellular
Clade monophyletic
A taxon than include an ancestral or to everything and all the descendants
What is the sister taxon to animals
Choanoflagellates
Chanoflagellates are closely related to
Sponges. The choanocytes pretty much identical also DNA evidence