AND ALL CORRECT ANSWERS 2026-
2027 UPDATED.
Origin of Life (4 stages) - Answer 1. Nucleotides and Amino Acids... before cells
2.Nucleotides and Amino Acids polymerized to become DNA, RNA and Proteins
3.Polymers became enclosed in membranes
4.Polymers in membranes attained cellular properties
Dates of Origin of Life - Answer 13.8 bya the Big Bang
4.6 bya the solar system began
Earth age is 4.5 byo
in 4- 3.5 bya life emerged on earth
(3) Hypotheses to Origin of Organic Molecules - Answer 1. Extraterrestrial Hypothesis:
Meteorites brought organic molecules (Carbon and aa the like) into the Earth.
- Opponents argue that the carbon would have burned up in the atmosphere
2.Reducing Atmosphere Hypothesis: Earth rich with NH3, O2 and H2 and that the components
formed redox reactions which spurred life; Stanley Miller-Urey
3. Deep-Sea Vent Hypothesis: the high temp and the low temp created gradient in which
organic molecules formed.
Protobiont - Answer an aggregate of prebiotically produced molecules and macromolecules.
Has a lipid bilayer
Characteristics of a Protobiont: - Answer 1. boundary to separate internal from external
2.polymers that contain info and enzymatic function
3.capable of self-replication
Living cells thought to have evolved from: - Answer 1. Coacervates
2.Liposomes
Why and what do scientist think to be the first macromolecule - Answer RNA because it can
replicate, hold information and has capabilities of enzymatic function
, Chemical Selection - Answer A chemical in a mixture with an advantageous trait that allows it
to replicate in number more than other chemicals in the mixture
Advantages of DNA/RNA/Protein synthesis today - Answer Information storage and
metabolism/cellular functions. DNA stores the info and allows RNA to do other tasks. Proteins
have larger catalytic potential and greater efficiency.
Radioisotope Dating - Answer Method of measuring amount of isotope as well as amount of
decay product to determine the age of a fossil.
Half-life is very important here and is the amount of time for half of an isotope to decay.
Factors that affect Fossil Record - Answer Anatomy, size, number, environment, time,
geological processes, palentology
History of Life on Earth (classification and important ones) - Answer 2 eras; Precambian and
Cambian eras
4 eons in Precambian: Hadeon, Archean, Proterozoic, Phanerozoic
Archean- Prokaryotic cells and Stromalites
Proterozoic- multicellular invertebrates w/ bilateral symmetry
Phanerozoic- proliferation of multicellular life
Stromalites - Answer Autotrophic cyanobacteria. produce O2 as waste and made way for an
anerobe enviorment
How eukaryotic cells though to have emerged - Answer by an archeal cell invaginate a
bacterium
Phanerozoic Eon - Answer Eras:
-Paleozoic:
-Mesozoic: rise and fall of Dinos
-Cenozoic: mammals and flowering plants diversified
Major changes to the environment in Earth developing stages - Answer Temperature
fluctuations, changes in atmospheric composition, shifting landmasses, floods and glaciation,
volcanic eruptions and meteorite impact
Why is Cambrian Period such a big deal - Answer -period from 543-490 mya