10.2 Study Guide Flashcards
State the following stages of mitosis in order: Anaphase, Metaphase, Prophase, Telephase, Cytokinesis.
Prophase - Metaphase - Anaphase - Telephase - Cytokinesis
Define a stem cell. Explain the differences between multipotent, pluripotent, and induced pluripotent stem cells.
A stem cell is a cell that has not yet differentiated and, therefore, performs no specific function within the body but has the potential to specialize into one of many. Multipotent stem cells have the ability to differentiate into a small variety of cell types that are usually all from the same type of tissue. Pluripotent stem cells have the ability to differentiate into any type of cell in the body and are naturally only found in embryos. Induced pluripotent stem cells are differentiated cells that have been artificially transformed back into pluripotent stem cells by humans.
What catalyzes cell differentiation? What kinds of events might activate these catalysts?
Cell differentiation is catalyzed by proteins known as transcription factors. These proteins are activated and deactivated mainly by events that alter the concentrations of different biomolecules and vital proteins throughout the body.
Describe how a cell’s appearance changes throughout the different phases of mitosis.
In the first stages of mitosis, a cell changes little externally, but internally, its nucleus is dissolved, its DNA is condensed heavily, and a web of mitotic spindle fibers is produced. In the middle stages, as the fibers attach to the cell’s chromosomes and split them in half, the cell stretches, and its cytoplasm begins to split into two forms. Around the end of the process, the cell’s organelles are divided between both elongated sides, and the cell fully divides itself into two pieces, which quickly repair themselves and become fully functional cells.
Fill in the blanks: After the mitosis of a cell into Cell A and Cell B, the DNA of Cell A and the DNA of the parent cell are _____, and the DNA of Cell B and the DNA of the parent cell are _____. Additionally, the DNA of Cell A and the DNA of Cell B are _____.
After the mitosis of a cell into Cell A and Cell B, the DNA of Cell A and the DNA of the parent cell are exactly the same, and the DNA of Cell B and the DNA of the parent cell are exactly the same. Additionally, the DNA of Cell A and the DNA of Cell B are exactly the same.
True or false: All cells in one body have the exact same DNA.
With this information in mind, why is it that cells can specialize to perform so many different functions? What is it that directs this specialization, and how does it do so?
True, all cells in one body have the exact same set of DNA as each other.
Despite all cells having the exact same set of DNA, what matters in their specialization is the expression of the genes within that code. This expression leads directly to the production of proteins that carry out specialized cell processes, and it is controlled and directed by special proteins called transcription factors. These transcription factors are activated by the body according to alterations in concentrations of vital biomolecules and functional proteins, and they can enhance or repress the expression of any gene and, therefore, the production of any protein and the performance of any function.
