Correct Answers
What are some factors required for life? ✅order
reproduction & growth
movement
response to environment
acquiring & utilizing energy
evolutionary adaptation
homeostasis
chemical evolution ✅early in Earth's history, simple chemical compounds, in the
presence of energy, combined to form more complex carbon-containing substances
prebiotic earth ✅no life
no atmospheric oxygen
no molecules that make up cells like DNA, RNA, amino acids, fats, sugars, etc
Theory of Chemical Evolution ✅1. energy from heat, very simple chemicals were
captured in chemical bonds...small reduced carbon-containing molecules such as HCN
and formaldehyde
2. simple molecules reacted to make more complex molecules (building blocks) - amino
acids, sugars, nucleotides, lipids (fats)
3. macromolecules formed by the linking together of building blocks - proteins,
polysaccharides, nucleic acids
4. one of the macromolecules acquired the ability to replicate itself
Where did chemical evolution happen? ✅atmosphere
alkaline deep sea hydrothermal vents
possible sources of energy on early earth ✅heat (ground still hot from initial solar
system formation)
electrical (lightning)
solar (earth not shielded from sun's rays by ozone)
2 components of scientific theories ✅a pattern in the natural world
a mechanism or process responsible for creating pattern
chemical evolution building blocks ✅amino acids
fats
sugars
nucleotides
,Could a small carbon molecule have evolved? ✅yes
Could simulations generate:
monosaccharides?
nucleotides?
lipids? ✅yes
no (not enough ribose is generated)
some kinds
Monomer Polymer
amino acids
nucleotides
monosaccharides ✅protein
DNA/RNA
polysaccharides (end in "ose")
proteins ✅info-containing polymers of 20 AA joined by peptide bonds
spontaneously fold into 3D structures
protein tertiary structure ✅determined by R group
needed to function
protein secondary structure ✅beta-pleated sheet
antibodies (protein) ✅recognize foreign bodies/invaders
receptors (protein) ✅receive chemical signals on cell surface from outside cell
transport proteins ✅move substances
ex. hemoglobin
Proteins serve as ______. ✅enzymes - end in "ase"
catalyze reactions
enzyme + substrate = product
*active site specific to each
T or F
DNA has no active site to catalyze reactions and is not structurally complex. ✅True
In prebiotic soup, _____ with ribose as part of RNA. ✅monosaccharide
ex. cellulose
, What is the mechanism that is responsible for descent with modification? ✅natural
selection
Species tend to ______ (produce more offspring than can survive). ✅over-reproduce
competition for resources will result
mortality must occur
T or F
Organisms evolve by natural selection. ✅False.
Populations evolve.
Structural, developmental, and genetic similarities derived from a common ancestor are
called ______. ✅homologous
Where do we find the evidence for evolutionary relationships? ✅developmental
homology
structural homology
genetic homology
fossil record
monophyletic group ✅a common ancestor and all its descendant groups
identified by "one-snip" test
nutrients required for life ✅energy source
carbon source
electron acceptor (like oxygen)
N, phosphate, and other inorganics
water
What chemicals are likely key intermediates in the formation of the biological molecules
in present day life? ✅formaldehyde (H2CO)
hydrogen cyanide (HCN)
some aa and organics (C-C bond) also formed
Which model did Miller's simulations support? ✅prebiotic soup
advantages of surface metabolism model over prebiotic soup ✅there are catalysts
chemicals are concentrated (solves dilution problem)
pyrimidines ✅one ring
have not been synthesized
purines ✅two rings
readily synthesized in Miller's experiments