Need help with Cell Bio please. It is very important to my final grade. Thank yo
ID: 80363 • Letter: N
Question
Need help with Cell Bio please. It is very important to my final grade. Thank you in advance.
Below are a series of false statement regarding the properties of cancer cells. Under each, explain why they are false.
1. Tumor cells invade and colonize territories that normally belong to other cells. ________________________________________________________________________
2. Unlike in normal tissues, cell death is extremely rare in tumors. ________________________________________________________________________
3. Tumor cells grow and proliferate in defiance of normal restraints. ________________________________________________________________________
4. Malignant tumors are composed of cells that grow and proliferate, but still have not acquired invasiveness. ________________________________________________________________________
5. A single mutation is enough to turn a normal cell into a cancer cell. ________________________________________________________________________
Explain how stem cells know which cell will remain a stem cell and which will begin differentiation. Include any/all described methods from the book/PPTs/internet. ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________
In medical oncology, PET (positron emission tomography) is used to selectively image tumors in the body and to monitor cancer progression and response to treatment. Before performing a PET scan, the patient should fast for at least several hours for blood glucose to be sufficiently low. At the time of the scan, the positron-emitting glucose analog fluorodeoxyglucose (FDG) is injected into the bloodstream and the patient is asked to wait for up to an hour while avoiding physical activity. Finally, the scanner moves slowly over the body to reveal the location of possible tumors. Why do you think the patient should avoid physical activity before the scan? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________
Define:
Totipotent: ______________________________________________________________
Pluripotent: ______________________________________________________________
Multipotent: _____________________________________________________________
Unipotent: ______________________________________________________________
Tumor-Supressor Gene: ____________________________________________________
Proto-oncogene: __________________________________________________________
What genes have you already discovered aid in maintaining pluripotency? (Hint: iPS) ___________________________________________________________________________
What is a hematopoietic cell, and how does it differ from stem cells? ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________
A researcher is studying limb regeneration in the newt Notophthalmus viridescens. She transplants skeletal muscle cells from a transgenic newt that expresses green fluorescent protein (GFP) in all of its cells into the limb of a wild-type recipient newt. She then amputates the recipient limb right at the site of the graft, such that the stump contains GFPexpressing cells. She repeats this experiment several times, finding that GFP is only detected in the muscle cells. Why would this be?
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Explanation / Answer
1. Tumor cells invade and colonize territories that normally belong to other cells.
Ans:This statement is true. In case of malignant tumours, tumour cells are metastasized form the tumour and invade a new place where normal cells are currently present. Then they started to grow in the new invaded point and started to acquire the area which is normally should be acquired by the normal cell.
2. Unlike in normal tissues, cell death is extremely rare in tumors.
Ans:Normal cell always has a specific period of life span. They died after that period bt the process called programmed cell death or apoptosis. In case of cancerous cell die to mutations the apoptosis is inhibited. Protein or enzymes are working to initiate apoptotic pathway are either inactivated due to mutation or their expression level in decreased. Due to this type of event cancerous cells are also behave like immortal. However, in normal cells apoptosis in stem cell are also extremely rare. As they lifelong supplies the new differentiated cells they itself does not undergoes cell death.
3. Tumor cells grow and proliferate in defiance of normal restraints.
Ans:This statement is False. Tumor cells grow due to uninhibited cell proliferation. Cells present in the territory of a tumor cell do not able to affect its growth.
4. Malignant tumours are composed of cells that grow and proliferate, but still have not acquired invasiveness.
Ans:This statement is False. Malignant tumour only called when they got the invasive property which is called metastasis. Rather than, benign tumour cells are composed of cells that grow and proliferate but still not acquired invasiveness property.
5. A single mutation is enough to turn a normal cell into a cancer cell.
Ans: This statement is False. Commonly cancer is caused due to accumulation of several mutations.
Explain how stem cells know which cell will remain a stem cell and which will begin differentiation. Include any/all described methods from the book/PPTs/internet.
Stem cell is specialized biological cells which contains the property to differentiate into the specific type of cell simultaneously having the property to produce more similar type of stem cells through mitosis. Stem cells are not specialized differentiated cell. A major property of a stem cell is that it does not have any tissue-specific structures. Thus does not undergo any tissue specific functions.
Normally stem does not under goes any differentiation steps through which it able to produce specific type of cell. It undergoes mitosis and keeps supplying the production of stem cells. To differentiate stem cell need signal. During the need to produce a specific type of cell other cell produce the chemical signalling molecules which induce stem cell to move towards the production of differentiated cell. When this external signal arrives to th stem cell it activates the transcription of those genes which plays votal role in differentiation.
In medical oncology, PET (positron emission tomography) is used to selectively image tumors in the body and to monitor cancer progression and response to treatment. Before performing a PET scan, the patient should fast for at least several hours for blood glucose to be sufficiently low. At the time of the scan, the positron-emitting glucose analog fluorodeoxyglucose (FDG) is injected into the bloodstream and the patient is asked to wait for up to an hour while avoiding physical activity. Finally, the scanner moves slowly over the body to reveal the location of possible tumors. Why do you think the patient should avoid physical activity before the scan?
PET is a powerful medical imaging procedure which hepls demonstrate the function of a organs. It is used primarily as a diagnostic tool in oncology. To detect cancer, a radiopharmaceutical (like fluorodeoxyglucose or FDG) which contains both sugar (metabolized at a higher rate by cancer cells) as well as a radionuclide is commonly used. As cancer cells metabolize sugar at higher rates than normal cells, FDG uptake is much higher cancerous areas. The PET scan shows where the positions of gamma rays generate due to sugar uptake. PET scans are highly sensitive. Thus increased physical activity (which increases the uptake of sugar by normal cells) can create problems in differentiating between normal and pathologic uptake.
Define:
Totipotent: This type of stem cells has the ability to differentiate into embryonic and extraembryonic cell types from which a entire organism can be constructed.
After fertilization this type of cells are produced. So, zygote is an example of this type of cell.
Pluripotent: This type of stem cells has the ability to differentiate into three germ layer(Ectoderm, endoderm or mesoderm)cells.
Multipotent: This type of stem cells has the ability to differentiate into differentiate into a number of cell types, but all cell types are closely related to each other. Haematopoietic stem cell differentiates into different blood cells is an example of these type.
Unipotent: This type of stem cells cells can produce only single cell type, although, they have the self-renewal property which distinguishes them from non-stem cells.
Tumor-Supressor Gene: Tumor suppressor gene, or antioncogene, is a kind of gene which protects a cell to become a cancer by controlling the cellular proliferation mechanism. Loss function of this gene due to mutation can cause a cancer progression.
Proto-oncogene: Proto-oncogenes are a group of genes which cause normal cells to become cancerous when they are mutated.
What genes have you already discovered aid in maintaining pluripotency? (Hint: iPS)
Induced pluripotent stem cells (iPSCs) are genetically reprogrammed adult cells which are being forced to express genes and factors important for maintaining the defining properties of embryonic stem cells. OCT4, SOX2, and NANOG, these three genes have identified that they can induce Pluripotency in adult cell.
What is a hematopoietic cell, and how does it differ from stem cells?
Blood cells are also called hematopoietic cell. These cells are differentiated in specific type of blood cell, they does not possess any property of stem cell. These cells are actually originated from hematopoietic stem cell which is a pluripotent stem cell.
A researcher is studying limb regeneration in the newt Notophthalmus viridescens. She transplants skeletal muscle cells from a transgenic newt that expresses green fluorescent protein (GFP) in all of its cells into the limb of a wild-type recipient newt. She then amputates the recipient limb right at the site of the graft, such that the stump contains GFPexpressing cells. She repeats this experiment several times, finding that GFP is only detected in the muscle cells. Why would this be?
Skeletal muscle cells are already differentiated cell. They don’t produce any other organ form them. Thus the GFP expression cells are always confined in skeletal muscle in the wild type newt.