ONS/ONCC ACTUAL CERTIFICATION
PAPER 2026 QUESTIONS WITH ANSWERS
FULL SOLUTION.
■ Mitotic Phase (M phase). Answer- -Replicated chromosomes are
aligned, separated, and move into 2 new, identical daughter cells
-takes about 30-60 minutes
■ Major points of cell regulation are entry and exit from. Answer- -G1
checkpoint
-S Phase
-G2 checkpoint
-M phase
■ Restriction Point. Answer- -The transition from the resting phase into
an actively dividing phase (G0-G1) is a point where cellular
transformation can occur
,-During this time, cells pass through a transition phase known as a
restriction point
-Extracellular growth factors trigger reentry into G1, and GF are
required to send the cells past the restriction point, or the point of no
return
■ G0 Phase (resting phase). Answer- -After mitosis, cells may enter back
into the G1 phase or go into a resting phase, known as G0
-Most cells in the human body reside in G0
■ -Exceptions to this are those that are (Resting in G0 phase). Answer- -
Exceptions to this are those that are metabollically active, such as
-granulocytes
-and the epithelium of the GI tract
■ Cell Cycling Time. Answer- Amount of time from mitosis to mitosis
,■ Cell cycle video and image. Answer-
http://highered.mheducation.com/sites/0072495855/student_view0/chapt
er2/animation__how_the_cell_cycle_works.html
■ Check points in the Cell Cycle: Keeping it All Under Control. Answer-
-The cell cycle is carefully controlled through a series of checkpoints
-Variation in duplication or distribution of chromosomes during cell
division can alter the genetic information passed on to daughter cells,
leading to cellular dysfunction and disease, such as cancer
-These checkpoints monitor for DNA integrity and control progression
through mitosis
■ Progression through the cell cycle is controlled through two proteins:.
Answer- 1. cyclines (D, E, A, B)
2. Cyclin-dependent kinases (CDKs)
-Cyclin-CDK complex allows the cell to progress through each phase of
the cell cycle
■ Locations of proteins Cyclins (D, E, A, B) and CDKs. Answer- -(G0-
G1) : Cyclin D and CDK 4/6
, -Early S: Cyclin E and CDK 1/2
-Late S: Cyclin A and CDK 1/2
-G2: CDK 1/2 and cyclin A
-Before M: CDK 1 and Cyclin B
■ Inhibitory proteins. Answer- -prevent progression of the cycle when
DNA damage is detected
-An example of an inhibitory protein is p53 (AKA TP53)
■ DNA Damage Checkpoints. Answer- -If DNA damage is present, cells
are programmed to stop dividing or undergo apoptosis (programmed cell
death)
-The retinoblastoma protein (Rb), p53, and p21 are some of the most
well-understood inhibitory proteins (IP)
■ Inhibitory proteins p53. Answer- -Levels of this IP regulate several
important target genes
PAPER 2026 QUESTIONS WITH ANSWERS
FULL SOLUTION.
■ Mitotic Phase (M phase). Answer- -Replicated chromosomes are
aligned, separated, and move into 2 new, identical daughter cells
-takes about 30-60 minutes
■ Major points of cell regulation are entry and exit from. Answer- -G1
checkpoint
-S Phase
-G2 checkpoint
-M phase
■ Restriction Point. Answer- -The transition from the resting phase into
an actively dividing phase (G0-G1) is a point where cellular
transformation can occur
,-During this time, cells pass through a transition phase known as a
restriction point
-Extracellular growth factors trigger reentry into G1, and GF are
required to send the cells past the restriction point, or the point of no
return
■ G0 Phase (resting phase). Answer- -After mitosis, cells may enter back
into the G1 phase or go into a resting phase, known as G0
-Most cells in the human body reside in G0
■ -Exceptions to this are those that are (Resting in G0 phase). Answer- -
Exceptions to this are those that are metabollically active, such as
-granulocytes
-and the epithelium of the GI tract
■ Cell Cycling Time. Answer- Amount of time from mitosis to mitosis
,■ Cell cycle video and image. Answer-
http://highered.mheducation.com/sites/0072495855/student_view0/chapt
er2/animation__how_the_cell_cycle_works.html
■ Check points in the Cell Cycle: Keeping it All Under Control. Answer-
-The cell cycle is carefully controlled through a series of checkpoints
-Variation in duplication or distribution of chromosomes during cell
division can alter the genetic information passed on to daughter cells,
leading to cellular dysfunction and disease, such as cancer
-These checkpoints monitor for DNA integrity and control progression
through mitosis
■ Progression through the cell cycle is controlled through two proteins:.
Answer- 1. cyclines (D, E, A, B)
2. Cyclin-dependent kinases (CDKs)
-Cyclin-CDK complex allows the cell to progress through each phase of
the cell cycle
■ Locations of proteins Cyclins (D, E, A, B) and CDKs. Answer- -(G0-
G1) : Cyclin D and CDK 4/6
, -Early S: Cyclin E and CDK 1/2
-Late S: Cyclin A and CDK 1/2
-G2: CDK 1/2 and cyclin A
-Before M: CDK 1 and Cyclin B
■ Inhibitory proteins. Answer- -prevent progression of the cycle when
DNA damage is detected
-An example of an inhibitory protein is p53 (AKA TP53)
■ DNA Damage Checkpoints. Answer- -If DNA damage is present, cells
are programmed to stop dividing or undergo apoptosis (programmed cell
death)
-The retinoblastoma protein (Rb), p53, and p21 are some of the most
well-understood inhibitory proteins (IP)
■ Inhibitory proteins p53. Answer- -Levels of this IP regulate several
important target genes
