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Extracting DNA from a strawberryElena, Ertem13/10/211. IntroductionBackground information: Each cell of an organism (plant or animal) has a set of genes which containthe instructions that make the organism function. This set of genes is called genomes, and the genesare made up of DNA.DNA is the recipe for each organism. It contains the genes that make each organism different fromothers and unique. Examples for humans: brown eyes, black hair, color blindness etc. Examples forstrawberries: More seeds, bigger seeds, more red, bigger size, smaller size etc.This is a drawing of what DNA looks like up closely:Strawberries cells are octoploids, which means that they have eight copies of DNA in each cell. Thisis much more than a human, who only has two copies of DNA in each cell. Therefore, we are usingstrawberries, because we can collect more DNA from just a couple of strawberries.DNA is found in the nucleus in a eukaryotic cell (animals, plants etc.), and it is spread around in aprokaryotic cell (bacteria, fungus etc.). In eukaryotic DNA is organized into chromosomes. DNA issuper small, so we can’t see it with our bare eyes, but when there is a lot and all clumped together,it is much more visible.The research question of this investigation was: Does the amount of DNA change depending on thestrawberry size? We set out to answer this question by extracting the DNA out of two different sizedstrawberries and comparing the amount.2. HypothesisOur hypothesis was that the amount of DNA will be different for each strawberry.We think this because the size of the strawberry can affect how many cells are in it, therefore theamount of DNA.Variables-
Independent- The strawberries.Dependent- The amount of DNA in each strawberry.Controlled- The ingredients and the process of extracting the DNA.3. MethodThe following equipment was used:- 70% rubbing alcohol, ½ a cup- Strawberries, 3- Salt, ½ teaspoons- Liquid dish soap, 1 tablespoon- Mixing bowl- Measuring cup and spoons- Small and large beaker- A strainer- A funnel- Zip-lock bags- A pair of tweezersSet up:1. Mix 1/3 of a cup of water with a half teaspoon of salt and a tablespoon of dish soap2. Place your rubbing alcohol in the freezer3. Put the strawberries with the stem removed in the Ziplock bag4. Put one tablespoon per strawberry of the saltwater solution5. Zip your plastic bag, and take out all the air6. Smush all the strawberries in the bag until they become a paste7. Strain the strawberry pulp in the beaker8. Take the rubbing alcohol out of the freezer9. Gently pour ½ cup of the chilled rubbing alcohol into the strawberry mixture10. Use the tweezers to extract the DNA from the mixture11. Put the DNA in a petri dish to weigh it12. Weigh the DNA on a weighing scale13. Record the weightHow it was conducted:After we collected all the DNA we could extract, we put it on a petri dish and then weighed it.Another group did the same as we did, but instead of getting 50 grams of strawberries in total, theygot three strawberries of 25 grams in total, which is half of what we got.These are some pictures we made:The DNA we collected in the weighing scale(It says 6 grams because it counted the petri dish):Pouring the alcohol into the mixture:
Breaking down the strawberries:Filtering the strawberry mixture:DNA separating:Collecting the DNA:4. ResultsThe measurements of the amount of DNA with different strawberries are presented in Table 1 and inthe graph in the “Analysis section”.The table below shows the weight of the strawberries and the weight of DNA extracted from thatspecific strawberry.Table 1: Strawberry DNA extraction resultsWeight of strawberries:50 grams25 gramsWeight of DNA extracted:5 grams3 grams
5. AnalysisThe bigger strawberries have more DNA than the smaller strawberries. The reason the biggerstrawberries have more DNA is because since they are bigger in size, and therefore have more cells.You need more cells (which each contain 8 copies of DNA) to make that extra mass, resulting in moreDNA being in the whole organism.6. ConclusionsFinal results: 50g Strawberry 5g DNA25g Strawberries 3gramsWas our hypothesis correct? Yes, it was correct, because in our experiment we found out thatdouble the amount of weight of our strawberries resulted in almost double the amount of DNAextracted from each one. Therefore, my results support my hypothesis which was that the bigger insize the strawberry, the more DNA it will contain.7. DiscussionThe experiment went well since it went exactly as planned. However, the weight of DNA extractedfrom the strawberries of double the weight was not exactly double when compared to thestrawberry with half size. This could be that the weighing scale rounded 2.5g to 3g. Anotherpossibility could be that one of the groups didn’t discard the weight of the petri dish.Next time, we could use a very precise weighing scale, and each group could check on each otherwhen weighing the DNA extracted.8. Bibliography-Website name: Microscope Master, (no year available for specific article) Year when websitewas created: 2010-2021, What are chromosomes: Available ml
-Website name: Wikipedia Commons, Year published: October 2020, DNA Simple, available athttps://commons.wikimedia.org/wiki/File:DNA simple.svg
Extracting DNA from a strawberry Elena, Ertem 13/10/21 1. Introduction Background information: Each cell of an organism (plant or animal) has a set of genes which contain the instructions that make the organism function. This set of genes is called genomes, and the genes are made up of DNA. DNA is the recipe for each organism.
