BIO 311C EXAM 2 QUESTIONS AND ANSWERS | BIOLOGY EXAM PREP & STUDY
GUIDE 2026/2027
How long ago did life start on Earth? What does the timeline look like? - ANS ✔✔-Life started
500 million years after Earth's formation
Bacteria -> Archaea -> Protists (unicellular) -> Protists (unicellular) -> Plantae -> Fungi ->
Animalia
Miller and Urey's experiment and basic results... - ANS ✔✔-Experiment: used basic molecules
(H, H2O, methane, ammonia) in a setup w/ high power electrodes to stimulate energy. Noticed
that simple sugars, amino acids, and organic acids were formed.
-Results: showed that monomers of complex molecules could have formed under the reducing
atmosphere present in the early periods of Earth's history.
Predict the logical process by which simple monomers were formed and led to polymers and
the early forms of cells - ANS ✔✔Atoms (natural) -> Molecules (reducing conditions) ->
Monomers (polymerization on solid support) -> Macromolecules (self-assembly) -> Protobionts
-Molecules are in reducing conditions (ex: shallow water beds) then turn into monomers.
Monomers can aggregate to form simple structures called protobionts. The protobionts can
incorporate other macromolecules. Simple liposomes have been shown to be formed by the
aggregation of lipids in an aqueous solution and would provide a structure for complexity to
evolve.
Explain why the first possible macromolecule could be RNA to store genetic information and be
able to catalyze reactions - ANS ✔✔-RNA could catalyze reactions and form a variety of
secondary structures similar to proteins, which may have allowed the formation of a self-
replicating cell. RNA can form spontaneously in prebiotic conditions. Once proteins are made
, they can make carbohydrates and lipids. DNA cam elater and only helped proteins evolve to be
more efficient enzymes
Different methods of microscopy - ANS ✔✔-Light Microscope: light is refracted. Observe live
specimens in their natural colors with stains
-Transmission Electron Microscope: electrons are aimed at a thin section of specimen. Study
internal ultrastructures and cross-sections of cells or structures
-Scanning Electron Microscope: electron beams scan the surface of a specimen coated with
gold. Used to view the surface features and the 3-D shape of ultrastructures.
Different methods of centrifugation - ANS ✔✔-Mircofuge: SMALL 0.1-2.0 mL tubes. Used for
molecular biology experiments
-Clinical: 5-15 mL. Used in clinical labs
-Floor Model or Tabletop: LARGE 1-50 mL. Used in most cell and molecular biology labs
-Ultracentrifuge: LARGE 1-50 mL. Most expensive and used only in some labs
Gel Electrophoresis - ANS ✔✔-Used to fractionate DNA, RNA, or protein molecules based on
their size. Molecules migrate depending on their size and electric voltage. Negative charges on
DNA and RNA make them migrate towards the anode (+). Large molecules move slow while
small move faster.
Understand the logical sequence of events in a cell fractionation and analysis experiment - ANS
✔✔Cell fractionation provides information about the composition of an organelle.
GUIDE 2026/2027
How long ago did life start on Earth? What does the timeline look like? - ANS ✔✔-Life started
500 million years after Earth's formation
Bacteria -> Archaea -> Protists (unicellular) -> Protists (unicellular) -> Plantae -> Fungi ->
Animalia
Miller and Urey's experiment and basic results... - ANS ✔✔-Experiment: used basic molecules
(H, H2O, methane, ammonia) in a setup w/ high power electrodes to stimulate energy. Noticed
that simple sugars, amino acids, and organic acids were formed.
-Results: showed that monomers of complex molecules could have formed under the reducing
atmosphere present in the early periods of Earth's history.
Predict the logical process by which simple monomers were formed and led to polymers and
the early forms of cells - ANS ✔✔Atoms (natural) -> Molecules (reducing conditions) ->
Monomers (polymerization on solid support) -> Macromolecules (self-assembly) -> Protobionts
-Molecules are in reducing conditions (ex: shallow water beds) then turn into monomers.
Monomers can aggregate to form simple structures called protobionts. The protobionts can
incorporate other macromolecules. Simple liposomes have been shown to be formed by the
aggregation of lipids in an aqueous solution and would provide a structure for complexity to
evolve.
Explain why the first possible macromolecule could be RNA to store genetic information and be
able to catalyze reactions - ANS ✔✔-RNA could catalyze reactions and form a variety of
secondary structures similar to proteins, which may have allowed the formation of a self-
replicating cell. RNA can form spontaneously in prebiotic conditions. Once proteins are made
, they can make carbohydrates and lipids. DNA cam elater and only helped proteins evolve to be
more efficient enzymes
Different methods of microscopy - ANS ✔✔-Light Microscope: light is refracted. Observe live
specimens in their natural colors with stains
-Transmission Electron Microscope: electrons are aimed at a thin section of specimen. Study
internal ultrastructures and cross-sections of cells or structures
-Scanning Electron Microscope: electron beams scan the surface of a specimen coated with
gold. Used to view the surface features and the 3-D shape of ultrastructures.
Different methods of centrifugation - ANS ✔✔-Mircofuge: SMALL 0.1-2.0 mL tubes. Used for
molecular biology experiments
-Clinical: 5-15 mL. Used in clinical labs
-Floor Model or Tabletop: LARGE 1-50 mL. Used in most cell and molecular biology labs
-Ultracentrifuge: LARGE 1-50 mL. Most expensive and used only in some labs
Gel Electrophoresis - ANS ✔✔-Used to fractionate DNA, RNA, or protein molecules based on
their size. Molecules migrate depending on their size and electric voltage. Negative charges on
DNA and RNA make them migrate towards the anode (+). Large molecules move slow while
small move faster.
Understand the logical sequence of events in a cell fractionation and analysis experiment - ANS
✔✔Cell fractionation provides information about the composition of an organelle.
