Chap 25 - Book Flashcards
Conceptual questions and definitions from Chap. 25. Follows outline of PP.
the broad pattern of evolution above the species level
macroevolution
The emergence of terrestrial vertebrates through a series of speciation events is an example of what?
macroevolution
The origin of key adaptations such as flight and the impact of mass extinctions on biodiversity are two examples of what?
macroevolution
Scientists hypothesize that processes could have produced simple cells through 4 main stages:
a. ____ synthesis of small ___ molecules (proteins, nucleic acids, etc.)
b. joining of these molecules into _____, such as proteins and nucleic acids
c. packaging of these molecules into ______, droplets with membranes that maintained an internal chemistry different from that of their surroundings
d. origin of self-replicating molecules that eventually made inheritance possible
a. abiotic, organic
b. macromolecules
c. protocells
Earth’s first atmosphere had ___ oxygen and was probably thick with ____ ____, along with nitrogen and its oxides, carbon dioxide, ____, _____ and hydrogen
little, water vapor, ammonia, methane
What did Oparin and Haldane independently hypothesize?
the early earth’s atmosphere was reducing (electron-adding)
What did Haldane suggest about the early oceans?
they were a solution of organic molecules (primitive “soup”)
What did Miller’s classic experiment prove?
organic matter can be produced by inorganic matter
T/F some evidence suggests that the early atmosphere was made up of nitrogen and carbon dioxide and was neither reducing nor oxidizing
True
Earth’s Origin: deep-sea hypothesis
a. organic compounds were first produced in deep-sea _____ _________. This could especially have happened in ____ _______ that release warm water.
a. hydrothermal vents, alkaline vents
T/F the volcanic-atmosphere but NOT the alkaline-vent hypothesis shows that the abiotic synthesis of organic molecules is possible under their conditions
False. the abiotic synthesis of organic molecules is possible under volcanic-atmosphere and alkaline-vent conditions
Is the presence of amino acids and nitrogenous bases sufficient for the emergence of life?
No
T/F laboratories have proven that the abiotic synthesis of RNA monomers can occur
True
By dripping solutions of ___ _____ or __ ____ onto hot sand, clay, or rock, researchers have produced polymers of these molecules
amino acids, RNA nucleotides
T/F it is possible that polymers of RNA nucleotides acted as weak catalysts for chemical reactions on early earth
True
All organisms must be able to carry out reproduction and energy processing. For the first abiotic protocells, how may have this condition been met?
vesicles
What increases the rate of vesicle self-assembly?
montmorillonite (soft mineral clay)
What was likely the first genetic material?
RNA
enzyme-like catalysts that play a role in protein syntehsis
ribozymes
Natural selection on the molecular level has produced ____ capable of ________ in the laboratory
ribozymes, self-replication
“Life as we know it may have been preceded by an “RNA world” in which small RNA molecules were able to ____ and to store _____ information about the ____ that carried them.”
replicate, genetic, vesicles
A vesicle has self-replicating, catalytic RNA. What would its daughters be?
protocells
The richest source of fossils
sedimentary rocks
sedimentary rock layers
strata
The order of fossils int tock strata tells us the ___ in which the fossils were laid down, but it does NOT tell us their ____ _______.
sequence, absolute ages
What does the order of fossils tell us about the fossil age? What does it not tell us?
relative age, absolute age
How can we determine the absolute age of a fossil (absolute does NOT mean errorless, but that an age is given in years vs. “before” “after”)
radiometric dating
A process based on the decay of radioactive isotopes
radiometric dating
half-life
the time required for 50% of the parent isotope to decay
T/F half-lives are affected by environmental variables but not temperature or pressure
False. half-lives are not affected by environmental variables, temperature, or pressure
When an organism dies, it stops accumulating ____ and the amount of _______ in its tissues does not change over time. However, the ____ in its tissues slowly decays into ______. Thus, by measuring the ratio of ____ to ____ in a fossil, we can determine the fossil’s age.
carbon, Carbon-12, carbon-14, nitrogen-14, Carbon-12, Carbon-14
If two volcanic layers surrounding fossils are determined to be 525 millions and 535million years old, how old are the fossils?
roughly 530 million years old
A standard time scale that divides earth’s history into four eons and further subdivisions
geologic time scale
Name the four eons in chronological order
Hadean, Archaean, Proterozoic, Phanerozoic
Name the four categories of the geologic time scale:
Eon -> Era -> Period -> Epoch
The three eras of the Phanerozoic eon:
Paleozoic
Mesozoic
Cenozoic
“the age of reptiles” is what era?
Mesozoic (Phanerozoic)
What era and eon are we in now?
Phanerozoic Eon -> Cenozoic Era
In what Eon did prokaryotes appear?
Archaean Eon
What marks the shift from the Archaean Eon into the Proterozoic Eon?
atmospheric oxygen
Single-celled and multi-celled eukaryotes appeared in what eon?
Proterozoic
The earliest direct evidence of life (3.5 maybe)
stromatolites
layered rocks that form when certain prokaryotes bind thin films of sediment together (why is this significant?)
stromatolites, earliest evidence of life
Where are stromatolites to be found, nowadays?
shallow marine bays
Know Table 25.1
Do you know it? Do you really?
