Topic One - Classification Flashcards
Who created taxonomy?
Carl Linnaeus
Who was the first to organize organisms, the Earth, and soul?
Aristotle was the first to do this.
Who came up with the kingdom classification system?
Carl Linnaeus made it.
What is the kingdom classification? What are its levels? Which is most to least inclusive?
It is essentially a taxonomic hierarchy based on shared anatomical characteristics. It goes by:
- Kingdom, which is the most inclusive
- Phylum
- Class
- Order
- Family
- Genus
- species, which is the most specific
What is the the binomial nomenclature?
It is a two word naming system, goes Genus species and is still used today.
What does the traditional five-kingdom consist of?
It had five kingdoms. The monera, Protista, fungi, plantae, and Animalia.
What is the monera?
It is unicellular organism and has no nucleus.
What is the protista?
It is unicellular and has a nucleus.
What is fungi?
It is uni/multicellular, has a nucleus, and are decomposers.
What is the Animalia and Plantae?
They have nucleus, and are multicellular.
How was the Traditional 5 Kingdom Classification System classified by?
It was organized by similarities and differences in observable morphological (how you look) and nutritional characteristics.
Why was the Traditional 5 Kingdom Classification System abandoned?
It was limited by physical abilities as you cannot tell things apart. Two organisms can look the same but can have different evolutionary backgrounds.
What does all life store that made it easier to differentiate organisms? How so?
Molecular biology changed everything. All life stores DNA and use ribosomes (rRNA) to translate this info into proteins.
Do the genes for rRNA change often? Can it be used as a marker?
No cannot change too much as it is conserved for all organisms, however, small changes can accumulate. Thus, this gene is used as a marker as it is the same for all organisms.
When we compared rRNA, what can be found?
We can track how much time as passed since a speciation event. When comparing rRNA sequences, the closely related = fewer differences. If it is distantly related, it has more differences.
What did the DNA and rRNA sequences produce for scientists?
It created the current 3-domain classification system, which consists of Eukarya, Archaea, and Bacteria.
List what is unique about the domain bacteria? What type of cell is it, what was it formerly, what do the cell walls have?
It is unicellular, prokaryotic, formerly in monera, it has a small radius (1-5 micrometers) and its cell walls are made up of a protein called peptidoglycan.
List what is unique about the domain archaea? What type of cell is it, what was it formerly, what do the cell walls have?
It is a unicellular, prokaryotic, formerly in monera, it has small radius (1-5 micrometers) and its cell walls are made up of a protein called pseudopeptidoglycan.
List what is unique about the domain eukarya? What type of cell is it, what was it formerly, what do the cell walls have?
It is uni/multi cellular, eukaryotic, are large (10x bigger than prokaryotic), and its cells walls are made up of cellulose or chitin.
What is unique to prokaryotes DNA? What else makes it different?
They have bacteria and archaea, single, circular DNA molecule. They have no membrane bound organelles.
What is unique to eukaryotes DNA? What makes it different?
They have eurkarya, has multiple, linear DNA molecules. They have an endomembrane system (organelles and membranes).
What is similar between eukaryotes and prokaryotes? What is the ribosome size of the two?
Both have DNA, plasma cell membrane, cytosol, and ribosomes. Prokaryotes is 70S while eukaryotes is 80 S.
Why are prokaryotic cells so small?
Because of diffusion rates, their SA is bigger than its volume, so cell exchange’s nutrients easier and quickly and can support the volume.
As the size of the prokaryotic cell increase, what happens to its volume and SA? By how do they each increase?
Both SA and Volume increase as size increases, however their ratio decreases. Surface area increases 4x whilst Volume increases 8x for every doubling of cell size.
What does the plasma (cell) membrane do?
It is the SA of cells, it is where cell exchanges nutrients with the environment and where energy ATP is made.
What three rates are the same for both a large and small cell?
Diffusion rates, membrane transport rates, and energy generation rates are the same for all. The time it takes for the nutrients and energy to the middle of the bigger cell is difficult.
How can eukaryotes be so large?
Because they have an endomembrane system that increases the internal SA of a cell, and call transport nutrients and energy within and throughout the cells.
What is a horizontal gene transfer?
Exchange of genes within species.
What is the endosymbiotic theory?
The eukaryotic organelles were originally independent prokaryotic cells. The mitochondria and chloroplast were likely formed when to organisms formed a relationship that was beneficial to both and became permanent; became one organism - an archaea and bacteria hybrid.
What is endosymbiosis?
The host cell was an archaea that was very hungry and the symbiont cell as was a bacteria that was efficient at aerobic respiration and producing ATP. Thus, the bacteria entered the cell and produced ATP for both cells and became the mitochondria. At some point in time, this occurred with the chloroplast as well.
What is the result of endosymbiosis today?
A hybrid is a eukaryote with a mitochondria and chloroplast.
What are the five pieces of evidence for endosymbiotic theory?
Mitochondria and chloroplasts:
- Are the same size as modern prokaryotes.
- Have single, circular DNA molecule like prokaryotes
- Divides by binary fission (like prokaryotes)
- Have 70S ribosomes like prokaryotes (eukaryotes have 80s) and are similar rRNA.
- Many other endosymbiotic associations exist (slug steals chloroplast, maybe have organelle as such on its own).
How can organisms be also classified by?
Their metabolism.
What do organisms need?
A source of energy, and a source of carbon.
What are the types of source energy organisms?
Phototroph - light eaters
Chemotroph - chemical eater
- chemo-organo-trophs “organic eaten” (2+ carbon eaten like glucose)
- chemo-litho-trophs “inorganic eaten” (1 carbon atoms, such as co2, co, ch4, fe, so4)
What are the types of source of carbon?
Autotroph - self-eater (photosynthesis)
Heterotrophs - other-eater
