Cell Biology: Regulation of Cell Cycle

<p>A non-functional p53 protein. (A)</p> Signup and view all the answers

<p>The cell will proceed to divide only after the DNA has been properly repaired. (B)</p> Signup and view all the answers

<p>To allow for proper growth, development, and maintenance by controlling the timing and rate of cell division in different tissues and organs. (B)</p> Signup and view all the answers

<p>Terminally differentiated and no longer capable of undergoing cell division. (B)</p> Signup and view all the answers

<p>Embryonic cells have a significantly shorter cell cycle than skin cells. (C)</p> Signup and view all the answers

<p>Maintain the capacity to divide, but generally reserves this ability unless needed. (D)</p> Signup and view all the answers

<p>The specific type and function of the cell within the organism. (B)</p> Signup and view all the answers

<p>The point between interphase and the beginning of mitosis where there is essentially no going back. (A)</p> Signup and view all the answers

<p>Embryonic cells, skin cells, liver cells (C)</p> Signup and view all the answers

<p>They are not capable of undergoing cell division. (B)</p> Signup and view all the answers

<p>The cell will initiate DNA synthesis and proceed through the cell cycle regardless of external signals. (A)</p> Signup and view all the answers

<p>Whether the cell has sufficient energy reserves for division (D)</p> Signup and view all the answers

<p>The cell will undergo irreversible separation of sister chromatids. (C)</p> Signup and view all the answers

<p>The cell size and nutritional status (D)</p> Signup and view all the answers

<p>Liver cells can re-enter the cell cycle if triggered, while nerve cells are terminally differentiated and permanently reside in G0. (D)</p> Signup and view all the answers

<p>It is the last checkpoint before irreversible commitment to chromosomal replication. (C)</p> Signup and view all the answers

<p>Via a combination of internal and external signals at critical checkpoints. (D)</p> Signup and view all the answers

<p>The cell is performing its normal functions without preparing for division. (C)</p> Signup and view all the answers

<p>To halt cell division when abnormalities are detected, preventing unchecked proliferation. (C)</p> Signup and view all the answers

<p>Capability to completely detach from the original site to form secondary tumors in different locations. (A)</p> Signup and view all the answers

<p>Regulation of chromosome maintenance, leading to unlimited cell divisions. (B)</p> Signup and view all the answers

<p>Interfering with DNA replication or cell division to stop rapid cell growth. (A)</p> Signup and view all the answers

<p>Regulating and assisting normal cell growth, development, and division. (A)</p> Signup and view all the answers

<p>By switching off touch-sensor genes, allowing cells to move freely and form tumors elsewhere. (C)</p> Signup and view all the answers

<p>Controlled cell differentiation during embryonic development (C)</p> Signup and view all the answers

<p>To provide the tumor with adequate nutrient delivery, sustaining cell growth and proliferation. (B)</p> Signup and view all the answers

<p>To activate or inactivate cell signals through phosphorylation. (C)</p> Signup and view all the answers

<p>They are regulatory proteins whose levels fluctuate during the cell cycle. (C)</p> Signup and view all the answers

<p>By triggering passage through different stages of the cell cycle through phosphorylation. (B)</p> Signup and view all the answers

<p>They suggest these regulatory mechanisms are essential for life and have been maintained across diverse species. (D)</p> Signup and view all the answers

<p>By halting cell division when cells become too crowded due to insufficient growth factors. (B)</p> Signup and view all the answers

<p>The necessity of cells to attach to a substrate in order to divide. (C)</p> Signup and view all the answers

<p>It is a target protein in the chromosome, activated by phosphorylation which enables cell division. (C)</p> Signup and view all the answers

<p>To aid in the repair of connective tissues. (A)</p> Signup and view all the answers

<p>They can be mutated into oncogenes that promote uncontrolled growth. (D)</p> Signup and view all the answers

<p>They inhibit cell division to ensure that cell populations do not expand unnecessarily. (B)</p> Signup and view all the answers

<p>Cell division that proceeds without normal control mechanisms, which leads to cancerous growth. (D)</p> Signup and view all the answers

<p>It facilitates the metaphase to anaphase transition. (C)</p> Signup and view all the answers

<p>It either activates or deactivates proteins. (D)</p> Signup and view all the answers

<p>Activation of the Cdk-cyclin complex at the G1/S checkpoint, triggered by growth factors. (A)</p> Signup and view all the answers

<p>Growth factors are necessary for cell division by acting as positive signals to the cell. (B)</p> Signup and view all the answers

The collaboration of multiple cells to regulate their division across tissues for growth and maintenance.

Different types of cells have varying frequencies of division throughout their lifecycle.

Cells in embryos divide rapidly, with a cycle taking less than 20 minutes.

Skin cells divide frequently, approximately every 12-24 hours.

Liver cells can divide but do so rarely, approximately every 1-2 years.

These cells do not divide after maturity and are permanently in G0 phase.

A resting state in the cell cycle where cells do not actively divide.

The cell cycle consists of interphase (G1, S, G2) and mitosis (M) followed by cytokinesis (C).

Mechanisms governing the progression and regulation of the cell cycle.

Critical points in the cell cycle where processes are assessed and possibly halted.

The primary decision point of the cell cycle, determining if DNA synthesis can begin.

Checkpoint that confirms DNA synthesis has been completed correctly before mitosis.

Checks if all chromosomes are attached to the spindle before sister chromatids separate.

Factors like cell growth and size that influence checkpoint decisions.

Factors such as growth factors that influence a cell's decision to divide or enter G0 phase.

p53 is a protein that stops cell division when DNA is damaged, allowing repairs.

Normal p53 allows cells with repaired DNA to divide again.

Abnormal p53 fails to stop damaged cells from dividing, leading to cancer.

p53 can trigger apoptosis in cells when damage is too severe to repair.

All cancers involve the shutdown of p53 activity, allowing uncontrolled division.

Cancer arises after a cell undergoes about 6 key mutations that promote uncontrolled growth.

Genes that, when activated, allow cells to grow uncontrollably.

Genes like p53 that normally prevent uncontrolled cell division and activate apoptosis.

Cancer cells can avoid the normal process of programmed cell death (apoptosis).

A mass of abnormal cells that remains localized and does not spread to other tissues.

A cancerous mass that spreads from the original site to other parts of the body, causing metastasis.

Methods like radiation and chemotherapy used to target rapidly dividing cancer cells.

Factors like UV radiation, chemicals, and genetics that can trigger mutations leading to cancer.

Chemical signals that provide cues for cellular activity, typically involving proteins.

Protein signals that promote cell growth and division based on internal and external cues.

A process where phosphate groups are added to proteins, often altering their activity.

Regulatory proteins that control the timing of the cell cycle.

Cyclin-dependent kinases; enzymes that, when activated by cyclins, phosphorylate proteins to regulate the cell cycle.

A combination that triggers stages of the cell cycle, allowing progression.

External signals that stimulate cell division and coordinate activity between cells.

A mechanism where crowded cells stop dividing due to limited growth signals.

The requirement for cells to be attached to a substrate in order to divide.

A growth factor that stimulates cell division in fibroblasts to heal wounds.

Normal genes that can become oncogenes when mutated, stimulating excessive cell growth.

A failure of cell division control leading to uncontrolled growth.