• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/54

Click to flip

54 Cards in this Set

  • Front
  • Back
Ancient Earth age?
age of 4.5 BY
Ancient Earth
- early reducing atmosphere including carbon dioxide, water, hydrogen sulfide, methane, no oxygen
Oldest Microfossils
prokaryotes, emerging ~3.5 bya
Good to know about Oldest Microfossils
Consider: Eukaryotic cells were not until ~2.1 bya & multicellular organisms not until ~700 mya
Miller Urey Experiment
included assembling a reducing atmosphere with H2, CH4, NH3, and H2S, placing this atmosphere over liquid water, increasing the temperature of the gases, and providing energy with electrical spark discharges which produced amino acid glycine, hydrogen cyanide, and formaldehyde
Good to know about Miller Urey Experiment
Consider: If the atmosphere had been an oxidizing one, life may never have arisen because oxygen is corrosive and tends to strip off electrons there by destroying organic compounds...the reducing atmosphere promoted buildup of organic compounds
Probable CHemical pathway to origin of life
C, H, O, N → CH4 and NH3 → amino acid → proteins
Properties of life
cellular organization, sensitivity, growth, development, reproduction, regulation, homeostasis, and heredity
Good to know about the Properties of Life
Consider: The diversity of life is the result of mutation, sexual reproduction, multicellularity, horizontal gene transfer, and endosymbiosis
Catalysis
can be carried out by enzymes and RNA acting as a ribozyme
Bacteria and Archaebacteria Domains
contain no eukaryotes
Good to know about Bacteria and Archaebacteria Domains
Consider: Archea and eukaryotes are more closely related to each other than to bacteria. One characteristic they (archea & Eukarya) share is tRNA methionine
Life's Diversity
results from sexual reproduction, endosymbiosis, horizontal gene transfer, and mutation
Good to know about Life's Diversity
Consider: Eukaryotic cells acquired mitochondria (purple and chloroplasts (from cyanobacteria) through endosymbiosis
Deep-Sea vent Hypothesis based on
formation of prebiotic organic molecules resulting from temperature gradients of the cold ocean water mixing with hot water and hot gaseous substances released from the vents
ET hypothesis
formation of prebiotic organic molecules resulting from early Earth being bombarded by carbonaceous chondritic meteorites carrying carbon to the early earth
POlymerzation of prebiotic organic molecules
prebiotic synthesis of polymers not possible in aqueous solutions but will form on clay surface
Characteristics of Probionts
- internal polymers contained information
-boundary membrane separating internal from external environments
- protobionts capable of self-replication
RNA
suggested to be first macromolecule found in protobionts
good to know about RNA
Consider: RNA would have been chemically selected for because it can act as an enzyme (ribozyme) and can self-replicate
Liposomes (lipospheres)
vesicle surrounded by a lipid layer - may have formed the hollow spheres of phospholipids
Coacervates
Droplets that form spontaneously from the association of charged polymers; tend to absorb and incorporate substances from environment so semipermeable membrane surrounding first protocell could have been very similar
Dna
found in nucleus, mitochondria, chloroplasts
Radioisotope dating
Fossils can be dated using a measured amount of a given isotope as well as the amount of isotope (decay product) produced when the isotope decays

Half-life – length of time required for exactly one-half of original isotope to decay
Good to know about Radioisiotope Dating
Consider: If you started with 10g of Carbon-14, in 5730 years you would have .5g of Carbon-14 and .5g of Nitrogen-14.
Earliest Cells
probably anaerobic, heterotrophic, prokaryotic and arose during Archean Eon
good to know about Earliest Cells
Consider: Protocells would have been present before the development of a true cell but would have had specific characteristics such as a lipid and protein membrane surrounding it and would have contained a biochemical pathway for energy metabolism.
Appearance of Hominids
Tertiary Period
Endosymbiosis
prokaryotic cells being engulfed and becoming internal symbionts within an early eukaryotic cell
Cambrian Explosion
rapid increase in major animal groups' diversity; oxygen levels support larger animals
Land PLants
appear in fossil record Ordovician Period
Reptiles
appear during Carboniferous Period
Dinosaurs
existed from the Triassic to the end of the Cretaceous
Mammals
arose from mammal-like reptiles in the Triassic but remained small and insignificant while dinosaurs dominated
Mass Extinction
have occurred about 4 or 5 times in fossil record, due in some cases to catastrophic changes
when did (oldest microfossils)Eukaryotic cells first appear?
2.1 bya
when did (oldest microfossils) multicellular organisms first appear?
not unitl 700 mya
what did the early reducing atmosphere comprise of?
CO2, H2O, hydrogen sulfide, methane, NO OXYGEN!
(miller urey experiment)
what negative effects could have occured If there was O2 present within the early reducing atmosphere.
O2 is corrosive and tends to strip off electrons there by distroying organic compounds.
(the reducing atmosphere promoted buildup of organic compounds)
The diversity of life results from:
mutation,
sexual reproduction,
multicellularity,
horizontal gene transfer
Endosymbiosis
Where did Eukaryotic cells aquire mitochondria?
(purple and chloroplast) from cyanobacteria through endosymbiosis.
polymerzation of prebiotic organic molecules will form on __________ but not possible in __________.
clay surfaces

aqueous solutions
Why would RNA be chemically selected for?
beacuse it can act as an enzyme (ribozyme) and can self replicate.
when did the earliest cells arise
during the Archean Eon
The earliest forms of life on earth are found in rocks
A. 1 million years old.
B. 4 million years old.
C. 1 billion years old.
D. 3.5 billion years old.
E. 4.6 billion years old.
D. 3.5 billion years old.
The term "reducing atmosphere" for the early earth means that the atmosphere
A. was much thinner around the surface of the earth than now.
B. contained only two or three kinds of gases.
C. contained little or no free oxygen.
D. contained little or no free nitrogen.
E. contained little or no carbon dioxide.
C. contained little or no free oxygen.
The organic soup in which the first cell is believed to have arisen probably contained
A. isolated atoms.
B. bubbling hot gases only.
C. algae and other microscopic organisms.
D. amino and organic acids.
E. nucleic acids and proteins.
D. amino and organic acids.
The eventual development of oxygen in the atmosphere meant that
A. most environments were no longer suitable for anaerobic prokaryotes.
B. most environments were no longer suitable for aerobic prokaryotes.
C. photosynthetic cyanobacteria declined in number.
D. a large portion of the history of life was devoted to eukaryotic evolution.
E. oxygen was needed in order for evolution to occur.
A. most environments were no longer suitable for anaerobic prokaryotes.
Which of the following is the correct order, from simple to complex, showing the origin of life?
A. proteins --> CH4 and NH3 --> amino acids --> C, H, O, N
B. C, H, O, N --> CH4 and NH3 --> amino acid --> proteins
C. C, H, O, N --> amino acids --> proteins --> CH4 and NH3
D. amino acids --> proteins --> C, H, O, N --> CH4 and NH3
E. CH4 and NH3 --> proteins --> C, H, O, N --> amino acids
B. C, H, O, N --> CH4 and NH3 --> amino acid --> proteins
A complex protein-rich cell shelters and supports the DNA genetic code, and the code is the blueprint for the cell proteins; thus is set the "chicken-or-the-egg" dilemma of which came first. This is probably solved by the discovery that
A. RNAs called ribozymes had enzyme functions and could have served as both genetic matter and enzymes.
B. reverse transcriptase can convert RNA back into DNA.
C. all DNA and protein can be distributed evenly inside and outside the nucleus.
D. some proteins are simply assemblages of guanine, cytosine, thymine, and adenine.
E. viruses can give rise to all of the cell molecules.
B. reverse transcriptase can convert RNA back into DNA.
Which statement is NOT true about a protocell?

A. It would have contained DNA as its genetic material.
B. It would have been present before the development of a true cell.
C. It would have had a lipid and protein membrane surrounding it.
D. It would have contained a biochemical pathway for energy metabolism.
E. It might have been like a coacervate droplet in which a semipermeable boundary allows some materials to be absorbed from the surrounding environment.
A. It would have contained DNA as its genetic material.
Which term does NOT apply to the first protocell?
A. fermentation
B. autotrophic
C. membrane-bound
D. single-celled
E. self-replicating
B. autotrophic
The first eukaryotic cells probably arose about _____ billion years ago.
A. 2.1
B. 2.5
C. 3.5
D. 4.5
E. 5.5
A. 2.1
The position of mammals in evolution is best described as
A. they dominate life in the sea.
B. they were among the first animals to live on land and their variety outstrips all living things known.
C. they arose from mammal-like reptiles in the Triassic but remained small and insignificant while dinosaurs dominated the land.
D. mammals gave rise to birds.
E. mammals have been present since plants and other organisms first appeared on land.
C. they arose from mammal-like reptiles in the Triassic but remained small and insignificant while dinosaurs dominated the land.