MCB 252 FINAL EXAM
QUESTIONS AND ANSWERS 2026
- 2027
What is LUCA and how long ago did LUCA exist? What is the
general interpretation of the observation that members of a single
gene family are found in all three domains of life? - ANSWERS-
LUCA stands for the Last Universal Common Ancestor. It refers the
last ancestor that was shared by all three domains of life:
Archaebacteria, Eubacteria, and Eukaryotes. That ancestor is thought
to have lived sometime around 3.6 - 4.1 billion years ago. The
observation that members of a single gene family are found in all
three domains of life, suggests that the progenitor gene that gave rise
to the family members existed in LUCA- before the time that the
three domains diverged. Thus we can infer that the progenitor family
member existed prior to 3.6 billion years ago.
what experimental technique or instrumentation was used to
determine kinesin step size? - ANSWERS-optical trap
Which type of reaction best describes microtubules that are
undergoing dynamic instability in vitro- steady state or equilibrium
(assuming GTP is always available)? - ANSWERS-steady state
what were the first two structures seen in eukaryotic cells in a light
microscope? - ANSWERS-nucleus, centrosomes
, what does centrosome mean/stand for? - ANSWERS-center body
what is the role of centrioles in centrosome function? - ANSWERS-
microtubule organizing center
"organize" the peri-centriolar material (PCM)
a newly assembled centriole is formed in the S-phase of the cell cycle.
when does a newly formed centriole become fully mature? -
ANSWERS-the following M phase
which part of the kinesins is evolutionarily related to myosins? -
ANSWERS-the heads
what are the two general types of activities associated with AAA
ATPase family members? - ANSWERS-threading
complex assembly/disassembly (clamp loading/unloading)
true/false
The two ends of a microtubule that is growing in vitro (with neither
end capped) have different critical concentrations. - ANSWERS-true
Which proteins are MAPS? - ANSWERS-proteins that bind the GTP
cap and promote assembly of microtubules
proteins that promote the bending of proto-filaments and promote
disassembly of microtubules
QUESTIONS AND ANSWERS 2026
- 2027
What is LUCA and how long ago did LUCA exist? What is the
general interpretation of the observation that members of a single
gene family are found in all three domains of life? - ANSWERS-
LUCA stands for the Last Universal Common Ancestor. It refers the
last ancestor that was shared by all three domains of life:
Archaebacteria, Eubacteria, and Eukaryotes. That ancestor is thought
to have lived sometime around 3.6 - 4.1 billion years ago. The
observation that members of a single gene family are found in all
three domains of life, suggests that the progenitor gene that gave rise
to the family members existed in LUCA- before the time that the
three domains diverged. Thus we can infer that the progenitor family
member existed prior to 3.6 billion years ago.
what experimental technique or instrumentation was used to
determine kinesin step size? - ANSWERS-optical trap
Which type of reaction best describes microtubules that are
undergoing dynamic instability in vitro- steady state or equilibrium
(assuming GTP is always available)? - ANSWERS-steady state
what were the first two structures seen in eukaryotic cells in a light
microscope? - ANSWERS-nucleus, centrosomes
, what does centrosome mean/stand for? - ANSWERS-center body
what is the role of centrioles in centrosome function? - ANSWERS-
microtubule organizing center
"organize" the peri-centriolar material (PCM)
a newly assembled centriole is formed in the S-phase of the cell cycle.
when does a newly formed centriole become fully mature? -
ANSWERS-the following M phase
which part of the kinesins is evolutionarily related to myosins? -
ANSWERS-the heads
what are the two general types of activities associated with AAA
ATPase family members? - ANSWERS-threading
complex assembly/disassembly (clamp loading/unloading)
true/false
The two ends of a microtubule that is growing in vitro (with neither
end capped) have different critical concentrations. - ANSWERS-true
Which proteins are MAPS? - ANSWERS-proteins that bind the GTP
cap and promote assembly of microtubules
proteins that promote the bending of proto-filaments and promote
disassembly of microtubules
