A comet assay is a technique used to determine the amount of double-strand breaks in DNA (DNA damage) in cells. The nucleus of an individual cell is placed on a microscope slide coated with an agarose gel. An electric
current is applied to the gel that causes DNA to move (electrophoresis), and the DNA is stained with a
fluorescent dye. When viewed using a microscope, undamaged DNA from the nucleus appears as a round shape
(the head), and the fragments of damaged DNA extend out from the head (the tail). The length of the tail
corresponds to the amount of the damage in the DNA (see Figure 1).
(a) To explain the movement of DNA fragments in the comet assay, identify one property of DNA and provide
reasoning to support how the property contributes to the movement during the comet assay technique.
(b) In a different experiment, cells are treated with a chemical mutagen that causes only nucleotide substitutions
in DNA. Predict the likely results of a comet assay for this treatment.

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

Consider the motion of the balloon and its air contents in terms of momentum. in step 1 above, the total momentum of the balloon and its contents was zero. recall that momentum = mv. both the balloon and the air inside it had a velocity of zero and therefore the total momentum was zero. now think about what happened when the air escaped from the balloon. a certain mass of air accelerated in one direction. in order to keep the total momentum of the system zero, the balloon itself (which has mass) had to accelerate in the opposite direction. use this scenario to you explain why the soda can rotates when the water squirts out of the escape holes. what was your hypothesis concerning the water-filled can? according to your data, do you think your hypothesis was correct? (be sure to refer to your data when answering this question.) summarize any difficulties or problems you had in performing the experiment that might have affected the results. describe how you might change the procedure to avoid these problems. give at least one more example of newton's third law in everyday life.

Fruit bats in central america eat bananas and other fruits. banana plants rely on bats for pollination. what would be the most likely consequence on the banana crop if fruit bats were eliminated from the area? the banana crop would increase because bats would stop eating the crops. the banana crop would decrease because bats would no longer pollinate the crops. the banana crop would remain constant because bees would replace the bats. the banana crop would remain constant because the plants would adapt using asexual reproduction.