Blog #1: Genetic Variation and Molecules

Hey guys!

For the first unit of this semester, we studied genetics in my biology class! This was all so interesting because we got to learn how we were made and why certain diseases occurred, we saw the possibilities and percentages of phenotypes within generations. We learned about how DNA ends affecting our overall organism and how. This complimented our knowledge of genetic variation because with this, we learned about the causes for diverse populations and species in the world!

Genetic variation is the difference between individuals or populations; it is the diversity in gene sequences. To make it clearer: without genetic variation, we would all be identical, and we would be susceptible to the same diseases–which is harmful for the human population. Genetic variation enables us to be unique, avoid diseases, and grow a population. This diversity in humans is essential to our species, since it makes us adapt and survive; Cristy Sada stresses the need for genetic variation in her video and the need for people to “live their own lives” and be unique. Genetic variation may occur by genetic mutations, but how? This happens through the process of transcription and translation. Transcription is the process through which DNA code is turned into mRNA code. This happens by changing the nucleotides with their “partners” (like A pairs with T or U and C pairs with G) and changing each letter with its pair. For example, if I have a DNA that is TAC/CGT, in RNA this would be AUG/GCA. Notice that instead of T we use U. This is because mRNA doesn’t have T in its nucleotides, so T is switched with U. When we get the new strand of mRNA, this has to go through the process of translation, where each codon, or 3 letter group, turns into an amino acid–further creating a polypeptide. This is where genetic mutations occur, whenever a letter in a codon changes, because then the amino acid changes, which changes the whole protein! With these genetic mutations it is possible to change the genetic variation in a population. This follows the central dogma, which is DNA -> RNA -> proteins. But how do these get passed on? Well, this DNA is passed on from parent to offspring, and through the process of meiosis, gametes are formed to create our unique selves.

These genetic mutations can also take place during meiosis, when crossing over gets screwed up. This may result in Trisomy-21 or other diseases that result from an error when crossing over in meiosis. In the sketch below, we can see how the nondisjunctions happen in meiosis, these result in deformities. Only one DNA replication error can be the cause of life, death, or deformity. A viable error refers to an error that is mismatched and then detected and repaired by the DNA polymerase. It was an error, but the DNA polymerase was able to detect it. When these errors are not repaired, severe genetic mutations take place. Mutations caused by environmental factors base back to evolution. We can see in Prisci’s video that many genetic mutations happen to adapt a species more to a habitat, and to protect them from survival. Her video is very very interesting, it has some specific facts that will make you understand genetic variation better, I really recommend it! With both genetic variations and mutations that help them adapt, these species are able to grow into a greater population. Environmental factors such as sunlight, radiation, and smoking can cause mutations.

Escalante, P. [SchoolPriscila4182]. (2016, February 10). Genetic Variation in Peacocks. Retrieved from https://www.youtube.com/watch?v=okL7-OPrPBA

Sada, C. [CristySasegovASFM]. (2016, January 30). Turner’s and Klinefelter’s, Non-binaries? Retrieved from https://www.youtube.com/watch?v=jw9S5fTHrDY