Question

Method 1. Remove the calyx (green leafy end) of the strawberry 2. Insert the strawberry into a zip lock bag and tightly seal the zip lock bag afterwards 3. Use your fingers to mash the strawberry until there aren't any large pieces remaining 4. Place a strainer on top a beaker and transfer the strawberry mixture into the beaker through the strainer. Use a spoon to push down the strawberry content through the strainer. Place this aside 5. Using another beaker, add 1/4 teaspoons of salt into 1/3 cup of cold water. Stir to combine the two. Wait 2 minutes before proceeding to the next step. 6. Add 2 teaspoon (10 ml) of detergent to the water and salt mixture. Stir to create the extraction mixture 7. Add the extraction mixture into the beaker which contains the strawberry. Mix the strawberry content with the extraction mixture to combine the two. 8. Add 5mL of pineapple juice to the beaker which contains the strawberry and extraction mixture. Stir gently. Wait 10 minutes before proceeding to the next step. 9. Insert the mixture into a test tube and fill it 1/3 of the way 10. Insert the same amount of 90% ethyl alcohol as the strawberry mixture. The test tube should be filled 2/3 of the way after the alcohol is added on top of the strawberry mixture 11. Let the test tube rest on the test-tube rack and wait for the DNA appear 12. Remove the DNA with a toothpick and place the DNA on a clean plate to observe 212

The time it takes for the DNA to reach the top

what would the dependent, independent, and controlled variables be? Please explain thank you

Answer 1

Variables

Dependent: Time taken by the DNA to appear Independent: Ripeness of the strawberries and accuracy in measurement Controlled: size of the strawberries

Explanation

Ripened fruits are more softer than thre non ripened ones. Because the hormones loosens its cell wall by breaking the fibres and make it soft. So it is easy to mash and extract DNA from the ripened fruits.

Also, the the extracted DNA appears between the alcohol and the DNA solution because the DNA does not get dissolved in alcohol.So it precipitates.

Proper mashing also has its role in making the DNA extraction accurate.Ripened fruits are easy to mash as the hormones makes its cell wall more elastic and expandable. So the ripeness of the strawberries takes a role in the time the DNA takes to precipitate. And the accuracy in the measrument of the extraction mixture also plays a role in the accurate appearing of DNA