Cell Cycle and Cell Division

These flashcards cover a range of topics related to the cell cycle, cell division, and key regulatory mechanisms involved in these processes.

What is the main function of the pancreas in the body?

Digestion and glycemia regulation.

Which signaling pathway is primarily involved in pancreatic cancer progression?

Ras/MAPK pathway.

What percentage of pancreatic cancers harbor mutations in Ras protein?

Approximately 74%.

What are the four main events of the cell cycle?

Growth, chromosome segregation, cell division, and chromosome duplication.

What are the two main phases of the eukaryotic cell cycle?

Interphase and M phase.

What occurs during interphase of the cell cycle?

The cell grows and replicates each of its chromosomes.

What is the role of growth factors in pancreatic cancer?

Promote cell proliferation.

During which phase does DNA replication occur?

S phase.

What happens during the G1 phase of the cell cycle?

The cell increases in size and produces new organelles and proteins.

What is duplicated during the G1 phase?

Centrosome.

What occurs in the S phase apart from DNA replication?

The cell continues to grow and duplicate its centrosome and organelles.

What preparations occur during the G2 phase?

Increased ATP production, synthesizing mitotic proteins, and maturing duplicated centrosomes.

What is the role of mitosis in the M phase?

Nuclear division occurs during mitosis.

What is cytokinesis?

Cytoplasmic division that follows mitosis.

How many stages are there in mitosis?

Five stages.

What are the stages of mitosis?

Prophase, prometaphase, metaphase, anaphase, and telophase.

What happens to sister chromatids during prophase?

Cohesion proteins hold sister chromatids together.

What is a kinetochore?

A protein complex located at the centromere of a chromosome.

What significant event occurs in prometaphase?

The breakdown of the nuclear envelope.

What occurs in metaphase?

All chromosomes are aligned in the middle of the cell and attached to microtubules.

What happens during anaphase?

Sister chromatids are separated and move to opposite spindle poles.

What are the major events in telophase?

Reassembly of the nuclear envelope around chromosomes and beginning of cytoplasmic division.

What structure facilitates cytokinesis?

Contractile ring of actin and myosin filaments.

How many daughter cells are produced by mitosis?

Two diploid daughter cells.

What distinguishes meiosis from mitosis?

Meiosis involves the separation of homologous chromosomes and results in haploid cells.

What initiates the cell cycle in eukaryotic cells?

A signal called a mitogen.

What is a Cdk?

Cyclin-dependent kinase that phosphorylates proteins for cell cycle progression.

What are cyclins?

Proteins with a cyclical pattern of synthesis and degradation.

What halts the cell cycle if DNA damage is detected?

The cell-cycle control system.

What is the function of checkpoint proteins in the cell cycle?

Ensure key processes occur in the correct sequence and halt the cycle if problems arise.

What is the G1 checkpoint?

A checkpoint that verifies the cell is ready to enter the S phase.

What happens if chromosomes are not properly attached during the M phase?

The cell cycle is paused.

How do Cdk inhibitors function?

They bind to and inhibit Cdk-cyclin complexes.

What activates the expression of S phase related genes?

Activation of G1/S-Cdk.

What is the key role of the APC during anaphase?

It triggers the cleavage of cohesion proteins.

List the three major checkpoints in the cell cycle.

G1 checkpoint, G2 checkpoint, M checkpoint.

What is the significance of Cdk phosphorylation?

Regulates Cdk activity.

How does the failure of chromosomes to attach affect cell cycle progression?

It prevents the cell from progressing past the M phase.

What are the key components of the cell-cycle control system?

Cyclins, Cdks, and Cdk inhibitors.

Describe the function of mitogens in the cell cycle.

They stimulate cells to enter the cell cycle.

What is the role of E2F in cell cycle regulation?

E2F promotes the expression of genes necessary for S phase.

How does the cell cycle respond to DNA damage?

It pauses to allow for repairs.

What types of cells have a cell-cycle control system?

Eukaryotic cells.

What is the purpose of the contractile ring during cytokinesis?

To divide the cytoplasm into two daughter cells.

Describe the outcome of experiments on cell-cycle regulation using mutant cells.

They can highlight the importance of specific proteins in regulating the cell cycle.

What signifies the end of the G2 phase?

The cell has replicated its DNA and is ready for mitosis.

What occurs during the transition from G1 to S phase?

The cell commits to DNA replication.

What leads to the maturation of the duplicated centrosomes in G2?

Signal for entering M phase.