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Sunscreen Lab - 35 pts

Last updated over 6 years ago
34 questions
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Last Name, First Name

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Class Period

UV Light and Skin Cancer

Exposure to the ultraviolet (UV) radiation in sunlight can lead to skin cancer caused by mutations in the DNA of skin cells. The most common type of damage from UV light is the formation of thymine dimers, or pairs of thymine bases bonded together. These mutations interfere with both replication and transcription of DNA.

Sunscreens receive ratings based on the amount of protection from UV radiation they provide. The higher the sun protection factor (SPF) the more radiation the lotion blocks. There are three grades of UV intensity radiation: UV-A, UV-B, and UV-C. Not all sunscreen lotions protect you from all of the three UV wavelengths. You need to read the labels to check for the type of protection provided by the product.
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Review: Skin cancer is the most common type of all cancers.

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UV light damages and causes mutations to the _________ inside skin cells.

3 letter word
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SPF stands for "sunscreen performance foundation".

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High ratings of SPF's in sunscreens means less protection from UV.

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There are three types of skin cancer cells: squamous, basal, and melanoma. Find the false statement.

Before we get into the lab, we are going to watch a short 2 minute video clip on "How to Check Yourself for Skin Cancer".
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Dermatologists recommend that you check yourself for skin cancer about

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You don't need to check your scalp because your hair covers your scalp and UV can't penetrate through your hair.

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While men are more likely to develop melanomas on the trunk of their body (chest area), women are more likely to develop melanomas on their legs.

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The A, B, Cs...can be used to determine if a spot or mole might have developed into skin cancer.

PROBLEM: There are many claims by advertisers about the quality of sunscreen products. The class is going to test three of these claims:

1. (Part A) Manufacturers of sunscreen products say that the Brand name products are better than buying Generic or Store Brand products. Name brands are more expensive than generic or store brands.
>Manufacturer's View: If consumer's buy name brands, manufacturers can increase their profits.
>Consumer's View: Consumers can save money by buying generic or store brands if they work as well as name brands.

2. (Part B) Manufacturers of sunscreen products say that consumers should always buy new sunscreen products each year as the product's potency decreases with age.
>Manufacturer's View: The more products that are purchased, the greater their profits.
>Consumer's View: If the product is still good after a year, consumers can save money by not buying new products.

3. (Part C) Manufacturers and Consumer Product Research show that the higher the SPF, the greater the protection from UV light. Higher SPF ratings on products cost more than lower SPF ratings.
>Manufacturer's View: There is more profit to be made on selling higher SPF ratings than lower rankings.
>Consumer's View: If lower SPF rated sunscreens work as well as higher ratings, then the consumer can save money by buying the lower SPF rated sunscreens.

You will now write a hypothesis for each of the three claims. Remember the correct format is "If"...."then" and that the "If" portion is the Independent Variable (what is being manipulated) and the "then" portion is the Dependent Variable (what is being measured in the experiment- you will be measuring the effectiveness of the sunscreen by observing a change of color after exposure to UV). I'm going to help you write the first hypothesis by presenting it as a multiple choice question. Use this one as a model to write the next two hypotheses.
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PART A: Claim: Brand name sunscreen products give better protection than generic or store brand products. Comparison by "cost". Select an appropriate hypothesis to test this comparison. Use the correct answer for a model for the next two hypotheses.

Remember the format is "If"....and "then"....
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PART B: Claim: New sunscreen products should be purchased each year because old products stop working
Write an appropriate hypothesis to test this comparison. Comparison by "age".

Remember the format is "If"..."then"
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PART C: Claim: Higher SPF ratings increase UV protection
Write an appropriate hypothesis to test this comparison. Comparison by "SPF" and "cost". Usually higher SPF sunscreens cost more than lower SPF sunscreens.

Remember the format is "If"... "then"...
MATERIALS: chromebook, different sunscreens, sunlight source, UV beads in plastic covering, plastic sheet to put the sunscreen on, timing device, paper towels to remove sunscreen between experiments
PROCEDURE:
  1. You will be assigned a partner.
  2. Place the two sunscreens that will be tested on the two separate squares on the clear plastic sheet (the space in the middle is for the control). You only need a small dot. Use your finger to dab the lotion and cover the square completely. You need to keep the lotion within the square because of the control bead in the middle without any sunscreen.
  3. Take the clear sheet with the sunscreen on it and place it in front of the UV beads that are in the plastic. Be sure to align the beads so that the end beads are behind the squares covered with sunscreen and the middle bead is not because it is your control.
  4. With the two pieces together, place the UV beads under the black light for 5 minutes (exposure to long UV rays)
  5. When the time is up, look from the back and observe your results.
  6. Record the results of your color change below.
  7. Clean off the sunscreen from the plastic sheet and prepare it for the next two comparisons. Repeat the same procedure for each of the 3 experiments. Be sure that the UV beads have returned to their original color, white, prior to beginning the next experiment.
  8. Clean up. Remember that everyone helps with clean up. Everyone's lab staitons must be clean and all materials returned to their proper place.
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PART A Experiment: Comparing Brand Name sunscreen against Generic/store brand named sunscreen. Your individual results. Compare the bead colors that were behind the sunscreens to your control color.

Add your Part A results to the Class Results on the whiteboard
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PART B Experiment: Comparing new sunscreen products against old sunscreen products. Your individual results. Compare the bead colors that were behind the sunscreens to your control color.

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PART C Experiment: Comparing Higher SPF sunscreen products against Lower SPF sunscreen products. Your individual results. Compare the bead colors that were behind the sunscreens to your control color.

Add your Part B results to the Class Results on the Whiteboard
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After considering your results for PART B: Claim: The new sunscreen products should be purchased annually because old products deteriorate and don't provide as much protection.

Do you reject or accept your original hypothesis? You have to answer based on your data and not personal opinion.

Add your Part C test results to the Class Results on the whiteboard
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Back to your original hypothesis for each of the three claims.
After considering your results for PART A: Claim: Brand name sunscreen products are better than generic or store brands and should be purchased even though they cost more.

Do you reject or accept your original hypothesis? You have to answer based on your data and not personal opinion.

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After considering your results for PART C: Claim: Higher SPF ratings give moe protection than lower SPFs and should be purchased even though they cost more.

Do you reject or accept your original hypothesis? You have to answer based on your data and not personal opinion.

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How did your individual results for Part A compare to the majority of the class results for Part A?

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How did your individual results for Part B compare to the majority of the class results for Part B?

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How did your individual results for Part C compare to the majority of the class results for Part C?

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Since melanoma skin cancer is the worse, it is important that your sun screen protects you from

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Back to your experiments. List 3 to 5 constants in these experiments. You receive a point for each correct constant that you provide.

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The bead without sun screen was your control. Describe the importance of having a control.

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Describe the type of data that was collected by the class.

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Select the best answer that points out the short comings of the type of data that was collected by the class.

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Due to the dramatically increasing number of melanomas, there is an increase in programs promoting skin cancer prevention and screenings.

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Melanomas often begin from a simple mole.

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Although there is a substantial rise in cases of melanomas, it continues to have a high survival rate.

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While fair skinned, red haired individuals are more at risk for skin cancer, all ethnic groups can get skin cancer.

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Since you can't get a sunburn on cloudy days or during the winter, you don't have to worry about UV protection during these time periods.

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Melanomas, the deadliest form of skin cancer, is most commonly found on the back.