Molecular Biology Final Exam UPDATED
Questions and CORRECT Answers
Approximately how many doublings can normal human fibroblasts undergo in culture?
(A) 5
(B) 50 to 100
(C) They will go on
proliferating indefinitely.
(D) They will not double at all,
but dispersing them
culture allows them to be
studied in isolation from
other cell types. - CORRECT ANSWER - (B) 50 to 100
After 50 to 100 doublings, the cells will stop growing and die.
How many genes does an E. coli have?
(A) 4,300
(B) 6,000
(C) 14,000
(D) 20,000-25,000 - CORRECT ANSWER - (A) 4,300
4,300 is the number of genes present in the bacteria E. coli.
Which of the following is a high-resolution light microscope technique for detecting interactions
between proteins?
(A) FRAP (fluorescence
recovery after
,photobleaching)
(B) FRET (fluorescence
resonance energy
transfer)
(C) MPEM (multi-photon
excitation microscopy)
(D) Confocal microscopy - CORRECT ANSWER - (B) FRET (fluorescence
resonance energy transfer)
A FRET signal requires that individual fluorescent dyes carried by two separate proteins be close
together in a complex. Energy transfer between fluorescent dyes is efficient only when the two
fluorescent dyes are brought close together.
The original atmosphere of Earth is thought to have been rich in
(A) CO2, N2, H2, H2S, and
CO.
(B) CO2, N2, O2, Ar, and Ne.
(C) CO2, N2, O2, Rn, and
Ne.
(D) CO2, N2, H2, Kr, and Xe. - CORRECT ANSWER - (A) CO2, N2, H2, H2S, and
CO.
These gases are thought to have been the most abundant gases in the original atmosphere of
Earth.
An E. coli cell under well-defined laboratory conditions divides about every
(A) 20 minutes.
(B) 2 hours.
(C) 12 hours.
, (D) 24 hours. - CORRECT ANSWER - (A) 20 minutes.
On rich laboratory medium, a typical E. coli cell will divide every 20 minutes.
The feature that most clearly separates eukaryotes from prokaryotes is the presence of _______
in eukaryotic cells.
(A) ribosomes
(B) oxidative phosphorylation
(C) DNA molecules
(D) a nucleus - CORRECT ANSWER - (D) a nucleus
Prokaryotic cells lack a nucleus.
In fluorescence microscopy, the immediate source of the light detected is light that has been
_______ the sample.
(A) absorbed by
(B) emitted by
(C) exciting
(D) scattered from - CORRECT ANSWER - (B) emitted by
The light detected is emitted by the sample. In fluorescence, the excitation light is absorbed by
the fluorescent group (electrons excited to a higher energy level), and light is then emitted as the
electrons fall back to their basal energy level.
Transmission electron microscopy is used to
(A) observe subcellular organelles and macromolecules.
(B) view living cells in three dimensions.
(C) view fluorescently labeled proteins in cells.
(D) study in single, thin sections the shapes of whole cells. - CORRECT ANSWER - (A)
observe subcellular organelles and macromolecules.
Questions and CORRECT Answers
Approximately how many doublings can normal human fibroblasts undergo in culture?
(A) 5
(B) 50 to 100
(C) They will go on
proliferating indefinitely.
(D) They will not double at all,
but dispersing them
culture allows them to be
studied in isolation from
other cell types. - CORRECT ANSWER - (B) 50 to 100
After 50 to 100 doublings, the cells will stop growing and die.
How many genes does an E. coli have?
(A) 4,300
(B) 6,000
(C) 14,000
(D) 20,000-25,000 - CORRECT ANSWER - (A) 4,300
4,300 is the number of genes present in the bacteria E. coli.
Which of the following is a high-resolution light microscope technique for detecting interactions
between proteins?
(A) FRAP (fluorescence
recovery after
,photobleaching)
(B) FRET (fluorescence
resonance energy
transfer)
(C) MPEM (multi-photon
excitation microscopy)
(D) Confocal microscopy - CORRECT ANSWER - (B) FRET (fluorescence
resonance energy transfer)
A FRET signal requires that individual fluorescent dyes carried by two separate proteins be close
together in a complex. Energy transfer between fluorescent dyes is efficient only when the two
fluorescent dyes are brought close together.
The original atmosphere of Earth is thought to have been rich in
(A) CO2, N2, H2, H2S, and
CO.
(B) CO2, N2, O2, Ar, and Ne.
(C) CO2, N2, O2, Rn, and
Ne.
(D) CO2, N2, H2, Kr, and Xe. - CORRECT ANSWER - (A) CO2, N2, H2, H2S, and
CO.
These gases are thought to have been the most abundant gases in the original atmosphere of
Earth.
An E. coli cell under well-defined laboratory conditions divides about every
(A) 20 minutes.
(B) 2 hours.
(C) 12 hours.
, (D) 24 hours. - CORRECT ANSWER - (A) 20 minutes.
On rich laboratory medium, a typical E. coli cell will divide every 20 minutes.
The feature that most clearly separates eukaryotes from prokaryotes is the presence of _______
in eukaryotic cells.
(A) ribosomes
(B) oxidative phosphorylation
(C) DNA molecules
(D) a nucleus - CORRECT ANSWER - (D) a nucleus
Prokaryotic cells lack a nucleus.
In fluorescence microscopy, the immediate source of the light detected is light that has been
_______ the sample.
(A) absorbed by
(B) emitted by
(C) exciting
(D) scattered from - CORRECT ANSWER - (B) emitted by
The light detected is emitted by the sample. In fluorescence, the excitation light is absorbed by
the fluorescent group (electrons excited to a higher energy level), and light is then emitted as the
electrons fall back to their basal energy level.
Transmission electron microscopy is used to
(A) observe subcellular organelles and macromolecules.
(B) view living cells in three dimensions.
(C) view fluorescently labeled proteins in cells.
(D) study in single, thin sections the shapes of whole cells. - CORRECT ANSWER - (A)
observe subcellular organelles and macromolecules.
