Final EXAM Flashcards
(104 cards)
Ch 25: Age of Earth
Formation of Earth: over 4.6 billion years ago (bya)
Ch 25: Hypothesis for how life emerged = 4 steps
- Abiotic synthesis of small organic molecules
- Joining of small molecules into macromolecules
- Packaging of macromolecules into protocells
- Origin of self-replicating molecules that eventually made inheritance possible
Ch 25: Origin of Eukaryotes = Endosymbiont Theory
Endosymbiont = cell that lives w/in another cell (host cells)
Evidence support endosymbiotic origin of mitochondria & plastids.
- Inner membranes have enzymes & transport systems homologous in living prokaryotes
- Own Circular DNA
- Replication similar to prokaryotes
- Machinery for protein synthesis
- Ribosomes are more similar to prokaryotic ribosomes
Ch 25: General Trends in the Evolution of Life on Earth
What Eon held the first single-celled organisms?
Earth’s sole inhabitants than how many years?
Oxygen levels increase or decrease?
Archaean Eon
More than 1.5 billion years
Oxygen levels Increase
Ch 25: General Trends in the Evolution of Life on Earth
What eon hold the first eukaryotic cells?
How many years?
Proterozoic Eon
~ 1.8 billion years
Ch 25: General Trends in the Evolution of Life on Earth
When was the Colonization of Land and the era?
~ 500 million years ago (mya)
Paleozoic Era
Ch 25: General Trends in the Evolution of Life on Earth
What era is the Age of Reptiles (“Age of the Dinosaurs”)?
What plant is dominant?
Mesozoic Era
cone-bearing plant
Ch 25: General Trends in the Evolution of Life on Earth
What era is the Age of Mammals?
What is the full human geologic record?
Cenozoic Era
Human:
Phanerozoic Eon, Cenozoic Era, Quaternary Period, Holocene Epoch
Ch 25: General Trends in the Evolution of Life on Earth
How many Mass Extinctions were there?
What are their names?
The Big Five
- Ordovician-silurian Mass Extinction
- Late Devonian
- Permian Extinction
- Triassic-Jurassic
- Cretaceous Extinction (K-T Extinction)
Ch 25: General Trends in the Evolution of Life on Earth
Ordovician-Silurian Mass Extinction
What year?
What became extinct?
455-430 MYA
Life: aquatic
Trilobites and early mollusks were drastically reduced in #
Ch 25: General Trends in the Evolution of Life on Earth
Late Devonian
What year?
What became extinct?
359 MYA
75% species died out
life in shallow seas affected more than other life forms
Ch 25: General Trends in the Evolution of Life on Earth
Permian Extinction
What is another name called?
What year?
What became extinct?
What happened?
“The Great Dying”
251 MYA
~ 96% of marine animal species drastically altered life in ocean
- extreme episode of volcanism
Produce enough CO2 to warm global climate
Oceans became more acidic
Ch 25: General Trends in the Evolution of Life on Earth
Triassic-Jurassic Mass Extinction
What year?
What caused?
What became extinct?
= 200 MYA
= 2-3 phases combined
= Likely causes by climate change, flood basalt eruptions, asteroid impact
= ~50% of all species became extinct
(Many species of plants survived)
(marine reptiles, some large amphibians, reef-building creatures & large # of cephalopod mollusks affected)
Ch 25: General Trends in the Evolution of Life on Earth
Cretaceous Extinction
What is another name?
What year?
What became extinct?
Where was it?
” K-T Extinction”
65 MYA
- Extinguished more than half of all marine species
- Eliminated many families of terrestrial plants & animals, including ALL dinosaurs
North America, Yucatan Peninsula, Chicxulub Crater
Ch 26: Proper format of a scientific name
First Part= Genus (capitilized)
Second Part = species (lowercase)
Written => underline
Type => italized
Ch 26: Phylogenies
Their uses [3]
- Show patterns of descent, NOT phenotypic similarity
- Sequence of branching in a tree does not necessarily indicate actual AGES of the particular species
IF AGES=> MOLECULAR CLOCK
- We shouldn’t assume that a taxon on a phylogenetic tree evolved from the taxon next to it
Ch 26: Phylogenies
Their uses in inferring phylogenies [4]
- Morphological Characters
- DNA sequences
- Microsatellites (repeats)
- Mobile elements
Ch 26: Order of the hierarchy of classification
Dear => Domain [Broadest]
King => Kingdom
Philip => Phylum
Came => Class
Over => Order
For => Family
Grape => Genus
Soda => Species [Most Specific]
Ch 26: Homologous vs Analogous characters
Types of each & how to distinguish b/w both
Homologous Characters: phenotypic & genetic similarities due to shared ancestry
Analogous Characters: similarities due to convergent evolution (not share common ancestor)
Distinguish b/w: Corroborative similarities
- # and intensity of similarities increase the more closely related two species
Ch 27: Reasons for prokaryote success [6]
- Many tolerate extreme conditions
- High Salinity (High salt conc)
- Radiation
- Low pH
- Extreme Temp (hot/cold)
- in rocks below earth’s surface
Ch 27: Unique characteristics of bacteria
- lack of membrane bound organelles
- unicellular
- microscopic size
Ch 27: Unique characteristics of bacteria
How Gram staining helps us identify bacteria?
Knows the large or thin layer of peptidoglycan
Stain Purple
- Gram (+) bacteria
- Large amount of peptidoglycan
- inhibit peptidoglycan cross-linking
- attack bacterial cells w/o harming human cells
Stain Pink
- Gram (-) bacteria
- Thin layer of peptidoglycan
- Outer membrane: lipopolysaccharides (lipid portions toxic)
- more resistant to antibiotics
Ch 27: Reproduction of Prokaryotes [2]
Reproduced by binary fission (asexual)
- very short generation times
Ch 27: Reproduction
High level of Genetic Diversity (3 things)
Rapid Reproduction, Mutations, Genetic Recombination