[Unit 4 FRQ] Cell Cycle and Cell Communication

[caroline-koffke]

Answer the following question below. Feedback will be provided!

Cells have a number of regulatory mechanisms in place in order to ensure proper growth.

a.) Name one cellular regulatory mechanism and how it prevents a cell from replicating if it is not supposed to.
b.) Name one reason why a cell would be given the signal to STOP replicating.
c.) What type of signalling is used for long-distance signals that can reach any cell type? Explain.

For the best possible answers to this question, view this post

[Sierra]

A) Cells use checkpoints in between G1 and S phase to make sure the cells DNA has not been damaged in some irreparable way.
B) Damaged DNA would be flagged at the checkpoint phase and if it was not able to be repaired in some way the cell will under go apoptosis. This ensures that the damaged DNA will not be replicated later on in Mitosis, which could cause cancer, from a rapid overgrowth of cells with damaged DNA.
C) Hormones are used for long distance signaling, the non-polar lipid hormones can be diffused through the plasma membrane because they are lipids. However, non lipid soluble hormones have to stick to a receptor on the outside of the target cell since they are water-soluble and cannot go through the plasma membrane.

[solei]

A) One cellular regulatory mechanism is the checkpoint that occurs at the end of the g2 phase in cellular division. This checkpoint allows to cell to continue only if its DNA has been replicated as planned.
B) One reason a cell would be given the signal to stop replicating is if it has a mutation in its dna, which could be harmful.
C) Endocrine signaling is used for long distance communication because they use hormones. For example a steroid, which don’t degrade easily and can get through the cell membrane without needing a specific receptor. This means that the signal is able to affect all cells.

[niyati_t]

a.) One cell regulatory mechanism are checkpoints in the cell cycle at the end of G1, S, and during mitosis. These checkpoints make sure that the cell has correctly gone through each stage of the cell cycle up to that point. Thus, if something is not correct, the cell is able to tell, and will stop the cell from continuing throughout the cycle and will prevent the cell from replicating.
b.)One reason a cell would be given the signal to stop replicating is before anaphase in mitosis. The spindles may not all properly be attached to the chromosomes, thus, when the chromosomes are pulled to opposite poles, there will be an unequal amount of chromosomes in each cell. This can cause many issues for a cell and can stop it from properly growing and performing its function. Thus, at the checkpoint, the cell would be given the signal to stop.
c.) Endocrine signalling is used for long-distance signals. In this type of signaling, a hormone is secreted from the cell. The hormone travels through the bloodstream, thus it can reach virtually anywhere cell type in the body.

[caroline-koffke]

Niyata, Wonderful response! You received 3/3 points. Thank you for participating!

[caroline-koffke]

Great job, Solei! You received 3/3 points for your response. Keep up the good work!

[caroline-koffke]

Awesome job, Sierra! You received 3/3 points for your response. Your answer to part C is very thorough! Keep up the good work.

[victor-jarquin]

a) One regulatory mechanism that prevents a cell from replicating if it is not supposed to are the various cell cycle checkpoints found throughout the cell cycle. Replication is prevented by these checkpoints when the concentration of CDK-Cyclin complexes aren’t high enough, thus preventing the cell from moving on to the next phase of the cycle. Failure to pass the checkpoints could lead to apoptosis or, if the cell is in G1, the transition to G0 phase, where the cell does not work towards replication.

b) A cell would stop replicating if DNA damage has not been repaired, or if any chromosomes during metaphase are not attached to microtubules

c) The type of signaling used for long-distance signals which can reach any cell type is endocrine signaling.

[mryan0717_5965]

A) One cellular regulatory mechanism is quorom sensing in bacteria. The bacteria send out signals, and if there is too much of a concentration of these chemical signals, this prevents the bacteria from replicating further because the receptors on the bacteria can sense the concentration and send a signal to stop replication.
B) A cell may be given the signal to stop replicating if there are not enough resources in its environment to support the replication of the cell and maintain the functions of the cell or keep it alive.
C) Hormones are used for long distance signals and can reach any cell type. The steriod hormones, which are lipids/nonpolar molecules, can diffuse through the membrane of any cell, and elicit a response from the cell.

[piano3411_56956]

A) One cellular regulatory mechanism is the G2 checkpoint during interphase. The G2 checkpoint prevents a cell from replicating if it is not supposed to by checking for the presence of damaged DNA and if damaged DNA is present then the cell will not continue the cell cycle.
B) One reason why a cell would be given the signal to STOP replicating is because the cell has damaged DNA present.
C) The type of signaling used for long-distance signals that can reach any cell type is endocrine signaling. Endocrine signaling is a type of signaling in which the signals travel through the bloodstream in order to reach any cell type.

[sudhasinghmd_59270]

a) One cellular regulatory mechanism that prevents a cell from replicating if its not supposed to is the G1 checkpoint. The G1 checkpoint makes sure that the DNA isn’t damaged in any way, and if it is, it will either stop the continuation of mitosis, or fix the damaged DNA before mitosis continues.
b) If a cell is damaged in any way, it will be given the signal to stop replicating. The cell will try to fix the damaged cell. If that is not possible, the damaged cell will undergo apoptosis, or cell death.
c) Endocrine signaling is used for long-distance signals that can reach any type of cell. This is because they use hormones. Hormones can travel long distances without being damaged. They are also able to pass through the membrane easily, which means they can go through most cells very easily.

[yaboyagent]

[quote=“caroline-koffke, post:1, topic:8823”]
a.) One cellular regulatory mechanism is the spindle checkpoint, which makes sure that the chromosomes are properly attached to the spindle microtubules in an orderly fashion. If all of them are not bound to the kinetochores correctly, the cell halts division until this is fixed and division can successfully happen.
b.) A cell could be given the signal to stop replicating if the cells around it are too densely packed. This is known as density-dependent inhibition, when cells are too crowded around each other and there is no real reason for more of them to be made. This makes sure there is not an unregulated growth of cells and that the cells do not waste energy, as it is important to conserve energy.
c.) Endocrine signaling is used for long-distance signals that can reach any type of cell. Different glands in the brain such as the pituitary and thyroid release these hormones in order to specify a function. These long-distance signals have the ability to reach every single cell in the body through the bloodstream and can bind to receptors only on cells that have the specific receptors for them. Then, they signal a response in the cell.

[caroline-koffke]

Great work on this response! You would receive a full 3/3 points. Remember that cells may also be given the signal to stop replicating if they are mutated. If this signal is not sent, overgrowth, such as cancer, may develop. Nice work!

[caroline-koffke]

Great job, Victor! You would receive 2/3 points for this response. In order to gain your third point, you would need to explain endocrine signaling in more detail. Perhaps describe that hormones are most frequently the messangers for this type of signaling. Great work!

[caroline-koffke]

Great work on this response. You would receive 3/3 points for this, as you thoroughly explained all three parts.

[caroline-koffke]

Great work on this answer! You would receive 3/3 points, as you thoroughly explained each part. Nice answer for part c!

[caroline-koffke]

Great job on your answers here. You would receive 3/3 points! Your answer for part c is incredibly thorough and gives a great real life example to support the information provided. Nice work!

[sailsunku]

A) One cellular regulatory mechanism are the cell checkpoint at the end of the G1 phase. They ensure to check the DNA to make sure it is not damaged in any way, otherwise it halts replication. 
B) Sometimes the DNA genome is damaged which means the cell should not replicate, so that the damaged DNA is not passed down. This is a circumstance where a cell should be given the signal to stop replicating. 
C) Signaling with hormones can be used for long-distance to reach any cell type. This is because hormones can travel through the bloodstream and therefore can reach any cell type.

[samantha.mitike3778]

a) one cellular regulatory mechanism is the checkpoints, more specifically the checkpoints at the end of the g2 phase. It sends information on how successful the replication is going.
b) A cell would be given the stop signal if it had a mutation. It could be harmful to undergo the rest of the replication.
c) Hormones can and are used for long-distance signaling. Steroids can get through the cell membrane without the need for a receptor.

[grantespy_56359]

A. One cellular regulatory mechanisms are the flags and checks of the cell at the different stages of its life. The flags include the passing from the G1 phase to the S phase and the S Phase to the G2 phase. If the cell notices something is wrong it will release a signal ligand that the cell well then pick up an example of autocrine signaling telling the cell to stop replicating.
B. One reason a cell would be given the signal to stop replicating would be if there was a mistake in DNA replication. If the cell was allowed to carry on the malignant DNA could cause the cell to replicate out of control causing cancer. The cell will either freeze the cell until the damaged DNA is fixed or go under apoptosis.
C. Hormones are an example of endocrine long distance signaling that can reach any cell type. Synaptic signaling can be chained together for long distances but can only be transferred to nerve cells and its surrounding cell.s Hormones are released into the blood and can travel anywhere in the body binding to different cells.