Understanding DNA and Chromosomes: Key Questions Explored
School
Delta Academy, Las Vegas**We aren't endorsed by this school
Course
CE 123
Subject
Biology
Date
Dec 10, 2024
Pages
3
Uploaded by MagistrateBeaverMaster938
Princess Grace TicarMr. GoodsonBiology IAssignment Summary:In this assignment, you will think of scientific questions that will help you better understand the role of DNA and chromosomes in the expression of heritable traits inan organism. You will then conduct research to answer these questions. Finally, you will compose a typewritten document that states your questions and provides your answers.Background Information:DNA in the nucleus of a cell contains the genetic code that dictates the structure and function of organisms. DNA is compressed into structures called chromosomes. Chromosomes are made of segments of DNA called genes. Genes are the basic units of heredity in organisms and are transferred from parent to offspring. DNA contains the genetic code, or the set of instructions, in the form of triplet codons, forassembling amino acids into proteins. All organisms share a similar genetic code based on the same DNA codons. The order of the codons differs, allowing for diversity among organisms. Not all DNA codes for proteins. Some segments of DNA are involved in regulatory or structural functions. The function of other segments remains unknown.1)How is DNA compacted to form a chromosome?-To form Chromatin which is a coiled condensed structure, cells must first wrapDNA strands around proteins which ultimately packaged DNA inside the nucleus. To form the shape of chromosomes, chromatin is folded into higher levels of structure. Nucleosomes are histone proteins that act like molecular spools that form the strands of DNA into beaded units. Nucleosome’s purposeis to organize higher levels of the chromatin structure and also contains eight histones wrapped by DNA. These contain two copies of four different kinds of histones in a nucleosome H2A, H2B, H3, and H4. All having specialized functions such as H2A being a C-terminal tail which ultimately regulates nucleosome conformation, binding DNA to several other locations.2. How do cells experience separation, forming several types of cells in the human body?- With the help of genetics and the body’s interaction with the environment, cell differentiation occurs. It is commonly known that each organism starts out with one
cell. This one cell is responsible for carrying DNA coding, containing the proteins theadult organism will use. On the other hand, if the cell has released all proteins in one setting, it will not longer be functional. For the cell to successfully function, the cell must divide repeatedly and begin the process known as cell differentiation as it progressively divides. For the cells to become more specific, the cell lines must emerge. Through this process, the organism itself will be formed with hundreds of cell types from the process of cell differentiation. Stem cells are the original mass cells that have not gone through cell differentiation. The division of stem cells is unalike compared to normal cell division. Normal cell division typically creates two identical daughter cells. However, in the division of stem cells, it is an asymmetric cell division. In this process, one of the cells is identical to the parent cell. On the contrary, the other cell, a chemical trigger activates a process of cell differentiation which will allow the cell to begin the process of releasing the DNA of a cell type. Embryonic stem cells are a kind of stem cells that can differentiate into whole organisms and are known to be totipotent. Totipotent is when the cell is capable of forming into any type of cell found in the body.3. What are the roles to non-coding DNA?- Some functions of non-coding DNA include translational and transcriptional regulation of the sequences in protein-coding, DNA replication, scaffold regions, etc.The RNA counterpart is called non-coding RNA. Depending on the species, the amount of non-coding DNA varies. Typically, a small number of the genome is in control of coding proteins, but when the number increases, it has been shown to have regular functions. When a large amount of non-coding DNA is present, the majority of it shows no biological function. Introns, another type of non-coding DNA, is more than likely to be found in genetics. Some may be crucial when regulating gene expression. Ultimately, the purpose of non-coding DNA is to ensure that cells are functioning correctly.ReferencesAnnunziato, A. (2008). DNA packaging: Nucleosomes and chromatin | learn science at scitable. Nature.com. https://www.nature.com/scitable/topicpage/dna-packaging-nucleosomes-and-chromatin-310/Biga, L. M., Dawson, S., Harwell, A., Hopkins, R., Kaufmann, J., LeMaster, M., Matern, P., Morrison-Graham, K., Quick, D., & Runyeon, J. (2019). 3.6 Cellular Differentiation. Open.oregonstate.education; OpenStax/Oregon State University. https://open.oregonstate.education/aandp/chapter/3-6-cellular-differentiation/Li, Z., & Kono, H. (2016). Distinct Roles of Histone H3 and H2A Tails in Nucleosome Stability. Scientific Reports, 6(1). https://doi.org/10.1038/srep31437
Non-coding DNA — Knowledge Hub. (n.d.). GeNotes. https://www.genomicseducation.hee.nhs.uk/genotes/knowledge-hub/non-coding-dna/