Raul has scraped his knee and noticed that after a week it had almost completely healed. Raul wondered how the skin was able to repair itself while looking exactly the same as his non-injured skin. In 3-5 sentences explain how mitosis plays a role in healing skin after injury and is able to maintain the look of the existing, non-injured skin.(4 points)
During the healing process, after a knee scrape, mitosis plays a crucial role in skin repair. Mitosis allows for the regeneration of new cells to replace the damaged ones. Specialized cells called keratinocytes, located in the epidermis, undergo mitosis to create new skin cells. These new cells migrate to the site of the injury, where they divide and differentiate to form a new layer of skin that closely resembles the non-injured skin. This process of controlled cell division ensures that the new skin cells are an exact match to the existing, non-injured skin, allowing for the wound to heal without any noticeable difference in appearance.
Keeping some DNA needed by mitochondria in the cell's nucleus and some in the mitochondria itself provides several advantages. Firstly, having mitochondrial DNA (mtDNA) in the nucleus allows for efficient replication and repair since the nucleus has specialized machinery for these processes. Secondly, having some mtDNA in the mitochondria itself ensures a localized regulation of mitochondrial gene expression, allowing for quick adaptation to changes in the cell's metabolic needs. Additionally, by having a portion of mtDNA in the nucleus, it protects against damage or mutation in the mitochondria by providing a backup copy of essential genes. This way, the cell can maintain the integrity and functionality of mitochondria, which are crucial for energy production.
The process of gene expression begins with DNA, which contains the genetic information of an organism. DNA is transcribed into messenger RNA (mRNA) through a process called transcription. The mRNA transcript then undergoes a series of modifications, including the addition of a cap and a poly-A tail. Next, the mRNA leaves the nucleus and enters the cytoplasm, where it binds to ribosomes and undergoes translation. During translation, the mRNA is decoded by ribosomes to assemble amino acids in the correct sequence to form a protein. This process of gene expression allows for the synthesis of specific proteins based on the information encoded in the DNA.
In three to five sentences, explain the advantage of keeping some DNA needed by mitochondria in the cell’s nucleus and some in the mitochondria itself.(4 points)
In 3–5 sentences, construct a summary of the process of gene expression, starting with DNA and ending with proteins.(4 points)
