#1
Which phase of the cell cycle is characterized by DNA replication?
S phase
ExplanationS phase involves DNA replication in the cell cycle.
#2
Which phase of the cell cycle involves the actual division of the cell into two daughter cells?
M phase
ExplanationM phase encompasses the division of the cell into two daughter cells.
#3
During which phase of the cell cycle does the cell grow and carry out normal functions?
G1 phase
ExplanationG1 phase is when the cell grows and performs its normal functions.
#4
Which of the following is NOT a phase of mitosis?
Interphase
ExplanationInterphase precedes mitosis and is not a phase of mitosis.
#5
Which protein complex regulates the progression of the cell cycle by phosphorylating target proteins?
Cyclin-dependent kinase (CDK)
ExplanationCDK regulates cell cycle progression via phosphorylation of target proteins.
#6
What is the function of tumor suppressor genes?
Inhibit cell division
ExplanationTumor suppressor genes inhibit cell division to prevent tumor formation.
#7
What is the primary function of mitosis in multicellular organisms?
To produce identical daughter cells
ExplanationMitosis ensures production of identical daughter cells for growth and repair.
#8
Which cyclin is primarily involved in regulating the G1 to S phase transition?
Cyclin E
ExplanationCyclin E primarily regulates G1 to S phase transition in cell cycle.
#9
What is the function of the spindle apparatus during mitosis?
To separate chromosomes
ExplanationSpindle apparatus separates chromosomes during mitosis.
#10
What happens during cytokinesis in animal cells?
Cell membrane pinches inward
ExplanationDuring cytokinesis, the cell membrane pinches inward to divide the cell.
#11
What is the role of centrioles during cell division in animal cells?
To produce spindle fibers
ExplanationCentrioles generate spindle fibers essential for cell division.
#12
Which checkpoint ensures that DNA is undamaged before proceeding to mitosis?
G2 checkpoint
ExplanationG2 checkpoint verifies DNA integrity before entering mitosis.
#13
What role do cyclins play in cell cycle regulation?
They activate cyclin-dependent kinases
ExplanationCyclins activate CDKs to regulate cell cycle progression.
#14
What is the function of the anaphase-promoting complex (APC/C) in cell cycle regulation?
It targets proteins for degradation
ExplanationAPC/C marks proteins for degradation during cell cycle.
#15
What is the role of the p53 protein in cell cycle regulation?
To promote apoptosis
Explanationp53 promotes apoptosis in response to DNA damage.
#16
Which of the following is NOT a characteristic of cancer cells?
Activation of tumor suppressor genes
ExplanationCancer cells typically do not activate tumor suppressor genes.
#17
Which of the following is a consequence of a mutation in a proto-oncogene?
Uncontrolled cell growth
ExplanationMutation in proto-oncogenes can lead to uncontrolled cell growth.
#18
What is the primary role of checkpoint proteins in cell cycle regulation?
To repair damaged DNA
ExplanationCheckpoint proteins monitor and repair damaged DNA during the cell cycle.