On pages 132-134, Dr.Moalem goes into detail about how single genes code for more than just one protein. He also describes how if one gene is removed, the protein in question does not stop being produced because another gene may have a backup to code for the same protein. These concepts all relate to big idea #4, the concept that biological systems interact, and these systems and their interactions possess complex properties. The codes for proteins are found in the DNA within the cells nucleus. When cells replicate, they also replicate DNA. This process of replication, as we learned, is not perfect and mistakes can be made. What are some fail safes and quality control cellular organelles used during replication which help assure that the replicated DNA is perfect? How can this process also be related to Big Idea #1? What are the selective advantages to having these checks put into place? Are there any selective disadvantages?
Tim Mielczarek tmielcz5@gmail.com
Cell cycle checkpoints are control mechanisms that ensure the success of cell division in eukaryotic cells, mitosis. These checkpoints verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase. There are a variety of ways that the body uses in order to provide fail-safes for cell replication.
ReplyDeleteThis process can be related to the process of evolution driving the diversity and unity of life as the regulation decide whether or not a cell is capable of moving on to the next stage of development. Without this regulation large number of cells that eukaryotic organisms replicate would have large amount of flaws and the characteristics that make a human human would no long be unified. As shown by UIC they explain that cell cycle checkpoints are used as " a critical control point in the cell cycle where stop and go-ahead signals can regulate the cell cycle". They continue to explain that the three major checkpoints check for characteristics of size, nutrient availability, successful completion of previous steps and chromosome attachment. Other fail-safes for the cell cycle include the use of kinase, a protein, in order to activate or deactivate other proteins allowing the start and stop of the G1 and G2 checkpoints. Also the relation between MPF(cdk) and cyclin trigger the kinase and the mitosis process by increasing and decreasing. Another method according to Campbell is seen when the anchorage dependence and density dependent inhibition are explained where crowded cells stop dividing after the first layer of anchorage cells, cells that need a substratum to divide, are formed. The relationship between anchorage dependence and density dependent inhibition function in the body's tissues to ensure optimal cell density and location (p.242).
The selective advantages of having the regulation of the cell cycle is the cell can ensure that the replication process of the cell is correct and no mutated cells are formed. Therefore allowing the human body to have proper function and structure. Though when properly functioning the cell cycle checkpoints are selective advantages some genes when mutated become selective disadvantages including the caretaker gene because the result is inherently decreased cellular success.
(Jimmy Wang, jimmypelewang@gmail.com)
http://www.uic.edu/classes/bios/bios100/lectures/mitosis.htm
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ReplyDeleteCell cycle checkpoints are control mechanisms that ensure the success of cell division in eukaryotic cells, mitosis. These checkpoints verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase. There are a variety of ways that the body uses in order to provide fail-safes for cell replication.
ReplyDeleteThis process can be related to biological systems interacting as the regulation process decides whether or not a cell is capable of moving on to the next stage of development. Without this regulation large number of cells that eukaryotic organisms replicate would have large amount of flaws and the characteristics that make a human human would no long be unified. In the journal of biology an article explains the relation between the cell cycle and cdk stating that “The cell cycle is driven by cyclin-dependent kinases (CDKs), which are activated by binding to cyclins that are specific for the different phases of the cell cycle and determine the targets of the kinases.” This shows that the cell cycle contains critical control points in the cell cycle where stop and go-ahead signals can regulate the cell cycle. The relation between MPF(cdk) and cyclin trigger the kinase and the mitosis process by increasing and decreasing. Another method according to Campbell is seen when the anchorage dependence and density dependent inhibition are explained where crowded cells stop dividing after the first layer of anchorage cells, cells that need a substratum to divide, are formed. The relationship between anchorage dependence and density dependent inhibition function in the body's tissues to ensure optimal cell density and location (p.242).
The selective advantages of having the regulation of the cell cycle is the cell can ensure that the replication process of the cell is correct and no mutated cells are formed. Therefore allowing the human body to have proper function and structure. Though when properly functioning the cell cycle checkpoints are selective advantages some genes when mutated become selective disadvantages including the caretaker gene because the result is inherently decreased cellular success.
(Jimmy Wang, jimmypelewang@gmail.com)
http://jbiol.com/content/8/10/88