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1) What is a tumor?

A) List and briefly describe 5 characteristics of a tumor (or tumor cells) as contrasted with the corresponding normal tissue (or cells).

B) What is the defining characteristic of a malignant tumor as opposed to a benign tumor?

C) How do these characteristics support the theory that carcinogenesis is a multistage (i.e. that more than one step occurs during the development of cancer)? Can you suggest a way that one one genetic (or epigenetic) alteration could lead to multiple characteristics of a tumor (hint: consider pleiotropy):

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Nelly Stracke
Nelly StrackeLv2
29 Sep 2019
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Related questions

1)What experiment was performed that allowed for scientists to finally agree that DNA is the genetic material within living organisms?

a.Understand the materials and scientific techniques used to come to this result.

2)What group of experiments led to the discovery of the mechanism used in DNA replication?

a.Understand the materials and scientific techniques used to come to this result.

i.What is a cesium chloride gradient?

ii.Where do 14N and 15N respectively fall along this gradient?

b.The results revealed that DNA replicates using which of the three proposed models?

i. Describe the mechanism of each model.

3)What is the role of the following proteins in DNA replication?

a.Helicase

b.Single strand binding proteins

c.Topoisomerase

d.DNA polymerase III

e.DNA polymerase I

f.Primase

g.Ligase

4)What extra steps are taken to be sure the lagging strand does not shorten each time DNA is replicated?

a.What is the role of telomerase in these “steps”?

5)In DNA repair, which enzyme has “proof-reading” capabilities?

1)Which type of cells within our bodies use mitosis to reproduce?

2)Does mitosis create a cell that is different or the same as the parent cell undergoing division?

3)Describe the DNA found in sister chromatids.

4)Describe the DNA found in homologous chromosomes.

5)What occurs during the following stages of the cell cycle?

a.G1 Phase

b.S Phase

c.G2 Phase

d.M Phase

What are the phases of mitosis? What events occur in each phase?

1)Does mitosis separate homologous chromosomes, sister chromatids, or both?

2)What is cytokinesis?

a.Which fibers of the cytoskeleton contract to pinch parent and daughter cells apart from one another in animals?

b.How do microtubules move chromosomes to the two poles of a dividing cell?

3)How are centrioles involved in this process?

a.How do plants form two complete cells during cytokinesis?

4)How do bacterial cells reproduce?

5)The cell cycle is controlled at “checkpoints”. What occurs at each of the following checkpoints?

a.G1 Checkpoint

b.G2 Checkpoint

c.M Checkpoint

6)How do cyclin and cdk act to control the G2 checkpoint?

7)If presented with the schematic of the M checkpoint, you should be able to explain perturbations to the system as well as if the cell will divide or stall at metaphase.

8)Cancerous cells form when the cell cycle checkpoints do not function correctly and continues to divide even though it is damaged in some way. How does the protein p53 function to keep these cells from dividing?

9)Normal cells follow certain rules of growth that cancerous cells do not follow. What are these rules (provide a short definition for each as well)?

10)What is the difference between a benign tumor and a malignant tumor?

The Case of the Aging Surfer

Seth, a thirty-eight year-old white male of Scandinavian descent, has lived his entire life in Southern Florida. He is very concerned with maintaining a "healthy" appearance. Seth is very athletic and especially enjoys surfing. He has been surfing since the age of twelve and he started making surfboards while he was in high school. After obtaining a college degree in marketing Seth decided to start his own business making surfboards and giving surfing lessons for a local resort near his home. During a routine physical examination the physician assistant that Seth sees commented on the presence and appearance of a small growth (approximately 2-cm in diameter) above Seth's right eyebrow. This growth was shiny with a pearly border, a central ulcer and engorged surface blood vessels. The physician assistant was concerned that this might be a tumor and asked Seth a number of questions to aid in the diagnosis. Seth reported that he noticed this growth approximately six months ago but thought nothing about it since he often developed "pimples" when he was working on surfboards because of the heat and dust. Seth noticed that the growth would occasionally bleed, but he thought the bleeding most often occurred when he absently scratched above his eyebrows when he was working. Seth also reported that after bleeding the growth would "crust over" and appear to heal, but not disappear. Seth also thinks the lesion has increased in size, but he can't be certain.

The physician assistant asks Seth to come back in two days to visit with the attending physician and encourages Seth to be sure to use sunscreen whenever possible, especially when he is surfing or teaching surfing classes. Upon returning to see the physician, Seth is told that he probably has a basal cell carcinoma. This, the physician explains, is a cancer that while not benign, rarely metastasizes and grows very slowly. This type of cancer usually occurs in areas that have the greatest exposure to the sun (i.e. the face, head, and neck). While this cancer would probably not metastasize, the physician suggests surgical removal to minimize damage to any underlying tissues and a histological examination of the excised tissue to confirm the diagnosis.

Seth is concerned that if this is indeed cancer he will have to undergo radiation and/or chemotherapy and suffer from both hair loss and nausea like his mother did when she was being treated for breast cancer 10 years ago. The physician assures Seth that these treatments are not required for basal cell carcinoma and explains that this cancer usually remains localized to the specific area of the skin and does not usually spread to other tissues, so radiation and chemotherapy would not be necessary. Seth then asks why it is necessary to remove the tumor if it will not spread and is told that while the tumor does not spread to other body areas it will continue to grow and also invade deeper layers of the skin, such as the dermis, and destroy normal tissues. Seth agrees to the procedure and schedules a follow-up appointment to discuss the results of the biopsy the following week. At the follow-up appointment, Seth is told that the lesion was indeed a basal cell carcinoma. He is told that it will be important for him to try to use both sunscreens, specifically those containing para-aminobenzoic acid or PABA, and protective clothing as much as possible to minimize the effects of the ultraviolet (UV) rays of the sunlight. Seth is also told that while he should not be overly concerned, he should also pay close attention for similar lesions in the future, since a person with a single basal cell carcinoma is likely to develop additional basal cell carcinomas in the future.

http://emedicine.com/derm/topic47.htm

http://www.skincancer.org

The Case of the Aging Surfer:

Define the bold terms in the text.

How are benign and malignant tumors similar and different from each other?

Identify and briefly describe the three most common types of skin cancer and the risk to individuals who have developed each of them.

What are oncogenes and how are they believed to be related to cancer?.

Identify both the primary risk factors that Seth presents with and other risk factors that may or may not relate to Seth's case.

The procedure that Seth experiences is called the Mohs Surgery. What does it involve?

How do chemotherapy and radiation therapy act as treatments for cancer?

8) Explain why tanning booths are actually more dangerous than sunlight exposure in increasing the risk of developing some form of skin cancer.

1)What are the inputs of photosynthesis?

2)What are the outputs of photosynthesis?

3)Light-Dependent Reactions

Where does the first stage of photosynthesis, the light-dependent reactions, occur within a chloroplast?

Where does the energy come from that drives these reactions?

What molecule donates an electron to the reaction center of photosystem II?

How is the energy of an electron changed as it moves along the ETC?

How does the electrical charge of the thylakoid membrane affect protons (H+) within the chloroplast?

Where does the electron that is donated to photosystem I come from?

What are the final products of this series of reactions?

What happens to each of the final products from this series of reactions?

4)Light-Independent Reactions (Calvin Cycle)

a.Where does the second stage of photosynthesis, the Calvin Cycle, occur within a chloroplast?

b.What are the direct inputs for these reactions?

c.What are the three steps to the Calvin cycle?

d.What are the final products of this reaction?

e.What role does rubisco play in the Calvin Cycle?

1)What experiment was performed that allowed for scientists to finally agree that DNA is the genetic material within living organisms?

a.Understand the materials and scientific techniques used to come to this result.

2)What group of experiments led to the discovery of the mechanism used in DNA replication?

a.Understand the materials and scientific techniques used to come to this result.

i.What is a cesium chloride gradient?

ii.Where do 14N and 15N respectively fall along this gradient?

b.The results revealed that DNA replicates using which of the three proposed models?

i. Describe the mechanism of each model.

3)What is the role of the following proteins in DNA replication?

a.Helicase

b.Single strand binding proteins

c.Topoisomerase

d.DNA polymerase III

e.DNA polymerase I

f.Primase

g.Ligase

4)What extra steps are taken to be sure the lagging strand does not shorten each time DNA is replicated?

a.What is the role of telomerase in these “steps”?

5)In DNA repair, which enzyme has “proof-reading” capabilities?

1)Which type of cells within our bodies use mitosis to reproduce?

2)Does mitosis create a cell that is different or the same as the parent cell undergoing division?

3)Describe the DNA found in sister chromatids.

4)Describe the DNA found in homologous chromosomes.

5)What occurs during the following stages of the cell cycle?

a.G1 Phase

b.S Phase

c.G2 Phase

d.M Phase

What are the phases of mitosis? What events occur in each phase?

1)Does mitosis separate homologous chromosomes, sister chromatids, or both?

2)What is cytokinesis?

a.Which fibers of the cytoskeleton contract to pinch parent and daughter cells apart from one another in animals?

b.How do microtubules move chromosomes to the two poles of a dividing cell?

3)How are centrioles involved in this process?

a.How do plants form two complete cells during cytokinesis?

4)How do bacterial cells reproduce?

5)The cell cycle is controlled at “checkpoints”. What occurs at each of the following checkpoints?

a.G1 Checkpoint

b.G2 Checkpoint

c.M Checkpoint

6)How do cyclin and cdk act to control the G2 checkpoint?

7)If presented with the schematic of the M checkpoint, you should be able to explain perturbations to the system as well as if the cell will divide or stall at metaphase.

8)Cancerous cells form when the cell cycle checkpoints do not function correctly and continues to divide even though it is damaged in some way. How does the protein p53 function to keep these cells from dividing?

9)Normal cells follow certain rules of growth that cancerous cells do not follow. What are these rules (provide a short definition for each as well)?

10)What is the difference between a benign tumor and a malignant tumor?

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