Topic 1: Classification of Life Flashcards
What are the 5 characteristics of living organisms
- They are organized
- They have a metabolism
- They respond to stimuli
- They reproduce
- They evolve over time
Entropy:
disorder
Do living organisms have high or low entropy?
Low entropy, meaning they are highly organized
Who made the Scala Natura, when, and what is it?
Aristotle in 384-322 BCE. It was one of the first systems to organize organisms through its complexity.
True or false: All organisms on the planet share a common ancestor.
True
In the Scala Natura, who was at the top?
God, then the angels, then humans
In the Scala Natura, who was at the bottom?
At the bottom were plants
Who formalized our binomial naming system?
Carl Linnaens
When was Carl Linnaens first publication?
1735
Genus
Homo (genus) sapiens
Epithat
Homo sapiens (epithat)
Did the systema naturae allow the same genus and epithat in the animal kingdom?
Yes. eg; Gorilla gorilla
What is the Acer saccharum?
The sugar maple tree
What is the Taxonomic Hierarchy?
The relative level of a group of organisms in a taxonomic hierarchy
Should the taxonomic hierarchy reflect evolutionary history?
Yes
Levels of taxonomy
Dear - Domain King - Kingdom Philip - Phylum Came - Class Over - Order For - Family Good - Genus Soup - Species
True or False: Species are more closely related to animals in their group than in another group outside of the genus
True
What is the branch of biology (that names classified species into groups of increasing broadness)
Taxonomy
What are the broadest units of classification?
Domain, then kingdom
Who discovered domain and when was it formalized?
Carl Woese in 1971, was created and formalized in 1990
Which kingdom was cancelled and divided into 2 domains
the kingdom munera was divided into domain bacteria and domain archaea
Kingdoms that did not change?
Animals, plants, fungi, protists
What are the 3 domains included in the phylogenetic tree of life?
Bacteria
Archaea
Eukarya
What are the similarities of domain bacteria and domain archaea?
They have prokaryotic cells, they are single celled, and they are small
What are the differences of domain bacteria and domain archaea?
Domain Bacteria:
- cell wall with peptidoglycan
- bacteria like ribosomes
- unbranched phospholipids in membranes
Domain Archaea:
- cell wall with pseudo-peptidoglycan
- eukaryotic like ribosomes
- branched phospholipids in membranes
What are the 3 different shapes of domain bacteria?
- cocci (strep)
- bacilli (lactobacillus)
- spirilla (syphillus)
Characteristics of Escherichia Coli
- In our colon
- lives in guts
- provides us with vitamin K
Characteristics of domain archaea?
- most are extremophiles (live in extreme environments)
- acidophile (acid loving)
- thermophile (heat loving)
How does the Scala naturae differ from current understanding in biology?
Scala Naturae:
- ordered by complexity
- not related to biology
Current:
- All organisms share a common ancestor
- Following ancestry is better than complexity
Explain systema naturae (what it is, who created it, and when was it created?)
This system formalized the binomial naming system of organisms. (Capitalized genus, lowercase epithet)
It was invented by Carl Linnaeus
Its first publication was in 1735
Binomial naming is underlined if handwritten and italicized if typed
True or false: Any organism in one of the categories would be the most closely related to another organism of the SAME ranking.
True
What does the taxonomic hierarchy reflect?
Evolutionary History
In taxonomy, each level is _________
nested
What was the taxonomic classification before domain was discovered?
Before we formalized that there was domain bacteria and domain archaea, we thought all the organisms (now known as domain) was just prokaryotic organisms that were in one kingdom called Monera
But ever since the discovery, the kingdom munera got canceled and the prokaryotic organisms were split up into two groups
What does the domain eukarya consist of?
Animals, plants, fungi, protists
At the root, there is the last universal common ancestor called the _______
Luca
Its division occurred
2.8 billion years ago into the 3 groups
Bacteria, eukarya and archaea
Eukarya and archaea division occurred
2.2 billion years ago
Explain bacteria based on metabolism, growth area, structure?
- Bacteria have diverse metabolisms
- They grow anywhere
- Have limited structural diversity
What is an important bacteria (we talked about in the lec) and its function (where it lives, its symbiosis character, vitamin)
E Coli
- typical human symbiont
- Lives in our guts
- Provides vitamin k
Where are archaea found and explain what this is called?
Archaea are found in extreme places suited to its environment (extremophiles)
Ex. acidophile - in acid
Ex. thermophile - in high temp
phile= loves
Describe the living condition of Picrophilus torridus (archaea) and where it was discovered
Discovered in the sulfur springs of Japan
- High temp
- PH of 0.5
Therefore its a super acidophile and thermophile
Explain what each eukaryotic organism is doing to its environment
Plants - photosynthesize
Animals - Ingest
Fungi - Absorbs
Protist - Do all
Describe the characteristics of all cells based on (membrane, inheritance, and their nutrient source)
All cells are
- Enclosed in a membrane
- Use DNA as genetic material
- Have cytosol
Describe the characteristics of Eukaryotic and prokaryotic cells based on (membrane, and size)
Eukaryotic:
- Have a enclosed membrane
- Have a large nucleus
- Bigger than prokaryotes (because it evolved)
Prokaryot:
- No enclosed membrane
- Smaller than eukaryotes
What are the differences between Eukaryotic and prokaryotic cells based on (nucleus, chromosome shape, membrane bound organelles, endomembrane system)
Eukaryotic:
- Have nucleus
- Have linear chromosome
- Have membrane bound organelles
- Have endomembrane system
Prokaryot:
- Have nucleoid
- Have circular chromosome
- Don’t Have membrane bound organelles
- Dont Have endomembrane system
Explain horizontal gene transfer from the bacteria to eukarya and how did it occur?
Bacteria gave eukarya chloroplasts and mitochondria through endosymbiosis
Horizontal gene transfer: part of bacteria genetics are getting moved to different branches.
Explain the endosymbiotic theory
Symbiosis: close relationship between two species
Endosymbiosis: one of the species involved in the symbiotic relationship is living inside of the other species.
1) Ancestral eukaryotic/prokaryotic/ancient archaea cell (host cell) engulfs a bacteria/prokaryote that is doing cellular respiration and becomes the mitochondria
2) Ancestral eukaryotic/prokaryotic/ancient archaea cell (host cell) engulfs a bacteria/prokaryote that is doing photosynthesis and becomes the chloroplast
How does this engulfing occur
Through invaginaitons (folding of the plasma membrane onto itself which creates a bubble)
The engulfing of the bacteria/prokaryote that is doing photosynthesis (chloroplast) gave rise to which eukaryotic organism
Just plants and protists have ___________
All Eukaryotic cells have ______________.
chloroplast, mitochondria
List the evidence for the endosymbiosis theory based on (size, dna, dna shape, division type)
Bacteria and chloroplasts
1) Are same size as modern day BACTERIA
2) Have CIRCULAR DNA like prokaryotes
3) Divide by BINARY FISSION like prokaryotes
4) The RIBOSOMES are similar to modern day bacteria than eukaryotic ones
