MCB 252 - Final Exam Question and
answers correctly solved 2025/2026
Roles of MTS in interphase and Mitosis - correct answer ✔1. Cease
interphase roles: organelle transport and positioning
2. New role: attach to, position, and move chromosomes
/
Transcription occurs in what size of the chromosome. - correct answer ✔2-
30nm
These are typically decondense and partially have histones.
DNA compaction example: - correct answer ✔Angel Hair Pasta in Lincoln
Theater
Scale by 1,000k,00
Nucleus: 10um 10 meters
DNA diameter is 2nm 2 mm
UIUC to Orlando, Florida = 1066
Events in Mitosis - correct answer ✔Chromatids are isolated.
Allows efficient segregation of sister chromatids.
Rebuild nucleus and go onto the next cell cycle.
Regulation of Dynamic Instability in Mitosis is due to - correct answer
✔Balance of MAPs v. Catastrophe Factors -> Dynamics
Increase Gamma- Turc at centrosomes
,Regulate proteins that are involved in MT assembly and disassembly.
Three classes of mitotic microtubules that move chromosomes. - correct
answer ✔Kinetochores
Astral
Polar
Kinetochore microtubules - correct answer ✔-centromere where two sister
chromatids are held together
-proteins and dna
-one set of mt that reach out and attach to kinetochore and attachment helps it
to reel in sis to appropriate spindle pole
Astral microtubules - correct answer ✔extending from the spindle pole out
towards the edges of the cell
looks like a star-radiating out
Polar microtubules - correct answer ✔They extend toward the center of the
cell but do not connect to the kinetochore.
Chromosome degradation general features - correct answer ✔Protein DNA
complex at centrosome - have multiple MTS attach to one sister chromatid
and the other microtubule to attach to the other sister chromatid.
2 types of chromosome movements - correct answer ✔1. Prior to metaphase
- move chromosomes to middle to line up on metaphase plate
A. capture chromosomes
B. move chromosomes to middle
2. Anaphase
, -sister chromatids have to move chromosomes to poles
Metaphase is split into two parts: - correct answer ✔Before anaphase -
chromosomes move to the center
Anaphase - chromatids separate from each other
After- sis move out toward spindle
Prior to metaphase - Mts from spindle pole have to reach out and capture sis
chromatids and then move to center, go to metaphase to anaphase
Proper v. Improper attachment to 2 spindles - correct answer ✔Proper
attachment -> tension -> stabilize MT at kinetochore
-stablilze = capture
Improper attachment -> no tension -> de-stabilize MT at kinetochore
-de-stabilize = release
How do Mts reach to one sis and the Mts from other spindle reach towards the
other sis? - correct answer ✔Two sis chromatids are identical- kinetochores
are identical and have equal probability.
Trial and error process - correct answer ✔If it doesn't get it right, it starts over
and tries again. One Mts attach to kinetochores they start reeling - properly do
this then we have tension the two sis chromatids are being pulled away from
each other - any other arrangement does not cause tension
If they incorrectly attach-break them and try again!
What does the chromosome passenger complex do? - correct answer
✔sense tension
answers correctly solved 2025/2026
Roles of MTS in interphase and Mitosis - correct answer ✔1. Cease
interphase roles: organelle transport and positioning
2. New role: attach to, position, and move chromosomes
/
Transcription occurs in what size of the chromosome. - correct answer ✔2-
30nm
These are typically decondense and partially have histones.
DNA compaction example: - correct answer ✔Angel Hair Pasta in Lincoln
Theater
Scale by 1,000k,00
Nucleus: 10um 10 meters
DNA diameter is 2nm 2 mm
UIUC to Orlando, Florida = 1066
Events in Mitosis - correct answer ✔Chromatids are isolated.
Allows efficient segregation of sister chromatids.
Rebuild nucleus and go onto the next cell cycle.
Regulation of Dynamic Instability in Mitosis is due to - correct answer
✔Balance of MAPs v. Catastrophe Factors -> Dynamics
Increase Gamma- Turc at centrosomes
,Regulate proteins that are involved in MT assembly and disassembly.
Three classes of mitotic microtubules that move chromosomes. - correct
answer ✔Kinetochores
Astral
Polar
Kinetochore microtubules - correct answer ✔-centromere where two sister
chromatids are held together
-proteins and dna
-one set of mt that reach out and attach to kinetochore and attachment helps it
to reel in sis to appropriate spindle pole
Astral microtubules - correct answer ✔extending from the spindle pole out
towards the edges of the cell
looks like a star-radiating out
Polar microtubules - correct answer ✔They extend toward the center of the
cell but do not connect to the kinetochore.
Chromosome degradation general features - correct answer ✔Protein DNA
complex at centrosome - have multiple MTS attach to one sister chromatid
and the other microtubule to attach to the other sister chromatid.
2 types of chromosome movements - correct answer ✔1. Prior to metaphase
- move chromosomes to middle to line up on metaphase plate
A. capture chromosomes
B. move chromosomes to middle
2. Anaphase
, -sister chromatids have to move chromosomes to poles
Metaphase is split into two parts: - correct answer ✔Before anaphase -
chromosomes move to the center
Anaphase - chromatids separate from each other
After- sis move out toward spindle
Prior to metaphase - Mts from spindle pole have to reach out and capture sis
chromatids and then move to center, go to metaphase to anaphase
Proper v. Improper attachment to 2 spindles - correct answer ✔Proper
attachment -> tension -> stabilize MT at kinetochore
-stablilze = capture
Improper attachment -> no tension -> de-stabilize MT at kinetochore
-de-stabilize = release
How do Mts reach to one sis and the Mts from other spindle reach towards the
other sis? - correct answer ✔Two sis chromatids are identical- kinetochores
are identical and have equal probability.
Trial and error process - correct answer ✔If it doesn't get it right, it starts over
and tries again. One Mts attach to kinetochores they start reeling - properly do
this then we have tension the two sis chromatids are being pulled away from
each other - any other arrangement does not cause tension
If they incorrectly attach-break them and try again!
What does the chromosome passenger complex do? - correct answer
✔sense tension
