Cell Division and Cancer Biology

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Questions and Answers

Define cancer.

A disease of unregulated cell division, genetic mutation often main cause

What are the two main types of reproduction at the cellular level?

Asexual and sexual reproduction

What is the difference between asexual and sexual reproduction?

Asexual reproduction produces offspring that are identical to the original cell or organism, while sexual reproduction produces varying offspring similar to the parent but with traits.

Explain the process of binary fission.

A form of asexual reproduction in single-celled organisms where one cell divides into two cells of the same size Signup and view all the answers

What are sister chromatids?

Chromosome after duplication with two copies Signup and view all the answers

What is the centromere?

Narrowed waist sister chromatid's are joined Signup and view all the answers

Define the cell cycle.

Series of stages from when cell is first born until own division Signup and view all the answers

What is cytokinesis?

Division of cytoplasm Signup and view all the answers

What are growth factors?

Proteins that stimulate division Signup and view all the answers

Why do crowded cells stop dividing?

Density dependent inhibition Signup and view all the answers

What is anchorage dependence?

Need for cells to be in contact with a solid surface to divide Signup and view all the answers

Define mutation.

Change in nucleotide sequence within DNA molecule Signup and view all the answers

What is a carcinogen?

Substances known to cause or increase chances of cancer forming Signup and view all the answers

What is the function of the cell cycle control system?

Cycling set of molecules within cell that triggers and coordinates key events in cell cycle Signup and view all the answers

What is a checkpoint within the cell cycle?

Critical control points where stop and go signals regulate the cycle Signup and view all the answers

What is apoptosis?

Programmed cell death Signup and view all the answers

What is the mitotic spindle?

Separate chromosomes composed of microtubules Signup and view all the answers

What is a kinetochore?

Specialized protein structure on centromere of sister chromatin Signup and view all the answers

What is the metaphase plate?

Cell equator, imaginary plane equal distance from two poles of cell Signup and view all the answers

What is the cleavage furrow?

Deepens to separate contents of 2 cells, contracting ring of microfilaments Signup and view all the answers

What is the cell plate?

Vesicles with cell wall material that grow outward and separate two cells Signup and view all the answers

What is the function of proto-oncogenes?

Promote cell division in presence of appropriate signals from growth factors Signup and view all the answers

What is an oncogene?

Mutated proto-oncogene that are genes that promote cancer Signup and view all the answers

What is the function of tumor suppressor genes?

Encode proteins that pause cell division, repair DNA, or initiate cell death, cause cancer when inactivated by mutation Signup and view all the answers

What is angiogenesis?

Growth of new blood vessels, to acquire oxygen and nutrients Signup and view all the answers

What is metastasis?

Spread of cancer cells beyond original site Signup and view all the answers

What is chemotherapy?

Using toxic chemicals to kill rapidly dividing cells, affect cancer cells that are spread throughout the body Signup and view all the answers

What is radiation therapy?

High-energy ionizing radiation to kill targeted cells, kills cells by damaging the DNA in cells Signup and view all the answers

What is targeted therapy?

Kill cancer cells by exploiting weakness caused by mutations/oncogenes, normal cells unaffected because gene expression is normal Signup and view all the answers

Cancer is one disease.

False (B) Signup and view all the answers

Each cell has the same number of chromosomes

False (B) Signup and view all the answers

Adult nerve cells divide frequently, while skin cells and cells lining the digestive tract rarely divide.

False (B) Signup and view all the answers

The DNA replication process is perfect—mistakes are never made.

False (B) Signup and view all the answers

What is the purpose of the mitotic spindle?

It is composed of microtubules, microfilaments, and intermediate filaments, and its purpose is to pull chromosomes to the poles of the cell during mitosis. Signup and view all the answers

Why is it important for a cell to duplicate its chromosomes before it divides?

To ensure that each daughter cell receives a complete set of chromosomes necessary for proper function and development. Signup and view all the answers

What is the difference between benign and malignant tumors?

Benign tumors remain at the original site without spreading, while malignant tumors invade surrounding tissues and can spread to other parts of the body. Signup and view all the answers

Why do cancer cells promote angiogenesis?

To obtain sufficient oxygen and nutrients to support their rapid growth and survival. Signup and view all the answers

What are the treatments for cancer?

Surgery (A), Chemotherapy (B), Radiation Therapy (C), Immunotherapy (D), Targeted Therapy (E), All of the above (F) Signup and view all the answers

List some environmental factors that can cause mutations.

Smoking, infections, UV radiation Signup and view all the answers

What is the purpose of a checkpoint in the cell cycle?

To ensure that the cell is ready to proceed to the next stage, preventing errors that could lead to uncontrolled cell growth. Signup and view all the answers

What does a cell do if a problem is encountered at a checkpoint?

The cell may pause and attempt to repair the problem, or if the damage is irreparable, the cell may undergo apoptosis, a form of programmed cell death. Signup and view all the answers

What role do growth factors play in cell division?

They act as signals that stimulate cell growth and division, particularly in the presence of appropriate signals from growth factors. Signup and view all the answers

How does cancer develop?

Cancer develops through a series of mutations that gradually accumulate in cells, leading to uncontrolled cell growth and division. Signup and view all the answers

How do mutations in the BRCA genes affect an individual?

Mutations in BRCA genes compromise the DNA repair system, leading to a lower ability to repair damaged DNA, increasing the risk of developing breast cancer. Signup and view all the answers

Only women can develop breast cancer since the BRCA1 and BRCA2 genes are not found in men.

False (B) Signup and view all the answers

Mutations in the BRCA genes increase the risk of people developing other types of cancer.

True (A) Signup and view all the answers

The vast majority of cancers are inherited.

False (B) Signup and view all the answers

What do proto-oncogenes do normally? What happens when they are mutated? Give an example of a proto-oncogene.

Proto-oncogenes normally promote cell division in the presence of appropriate signals from growth factors. However, when mutated, they can become permanently activated and stimulate uncontrolled cell division, leading to cancer. An example of a proto-oncogene is HER2, which is frequently mutated in certain types of breast cancer. Signup and view all the answers

What do tumor suppressor genes do normally? What happens when they are mutated? Give some examples of tumor suppressor genes.

Tumor suppressor genes normally encode proteins that pause cell division, repair DNA, or initiate cell death, preventing uncontrolled cell growth. When mutated, these genes can become inactivated, allowing unchecked cell division and contributing to cancer development. Examples of tumor suppressor genes include BRCA1, BRCA2, and p53. Signup and view all the answers

Why does cancer affect people more as they age?

Cancer typically takes time to develop, often requiring a series of mutations that accumulate in cells over time. As people age, they are more likely to have accumulated these mutations, increasing their risk of developing cancer. Signup and view all the answers

How does a tumor begin?

A tumor begins with the transformation of a normal cell into a cancerous one, often due to mutations in genes that control cell growth and division. Signup and view all the answers

How does cytokinesis in animal cells differ from cytokinesis in plant cells?

In animal cells, cytokinesis involves the formation of a cleavage furrow, a pinching inward of the cell membrane that eventually separates the two daughter cells. In plant cells, cytokinesis involves the formation of a cell plate, a new cell wall that grows between the two daughter cells. Signup and view all the answers

List the stages of mitosis.

The stages of mitosis are prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Signup and view all the answers

List the genes that have been identified as indicators of breast cancer risk.

BRCA1 and BRCA2 are two genes that have been identified as indicators of breast cancer risk. Signup and view all the answers

What are some potential ways to reduce the risk of developing cancer?

Lifestyle factors play a significant role in cancer prevention. Maintaining a healthy diet, engaging in regular physical activity, avoiding smoking, and minimizing exposure to known carcinogens can significantly reduce the risk of developing cancer. Signup and view all the answers

Explain what cancer is.

Cancer is a disease of unregulated cell division, often caused by genetic mutations. Signup and view all the answers

What is the difference between asexual reproduction and sexual reproduction?

Asexual reproduction produces offspring that are identical to the original cell or organism, while sexual reproduction produces offspring similar to the parent but with variation in traits. (C) Signup and view all the answers

Each eukaryotic chromosome is composed of only DNA.

False (B) Signup and view all the answers

What do proto-oncogenes do normally?

They promote cell division in the presence of appropriate signals from growth factors. Signup and view all the answers

What happens when proto-oncogenes are mutated? Give an example.

They become permanently activated, causing uncontrolled cell division. An example is the HER2 gene, which is frequently mutated in some types of breast cancer. Signup and view all the answers

What do tumor suppressor genes do normally?

They normally encode proteins that pause cell division, repair DNA, and initiate cell death. Signup and view all the answers

What happens when tumor suppressor genes are mutated?

They can be inactivated, leading to uncontrolled cell growth and potentially the development of cancer. Signup and view all the answers

Which of the following is NOT a common treatment for cancer?

Antibiotics (C) Signup and view all the answers

Briefly describe how chemotherapy works.

Chemotherapy uses toxic chemicals to kill rapidly dividing cells, which include cancer cells. Signup and view all the answers

How does radiation therapy work?

Radiation therapy uses high-energy ionizing radiation to damage the DNA in targeted cells, leading to their death. Signup and view all the answers

Which of the following is a good way to reduce the risk of developing cancer?

All of the above. (D) Signup and view all the answers

Flashcards

What is cancer?

A disease characterized by uncontrolled cell division, often caused by genetic mutations.

What is cell division?

The process by which a single cell duplicates its contents and divides into two daughter cells.

What is asexual reproduction?

A type of reproduction where a single parent organism produces offspring that are genetically identical to itself.

What is sexual reproduction?

A type of reproduction that involves the combination of genetic material from two parents, resulting in offspring with unique traits.