Integrated Science Day 8 September 24, 2012

Learning targets Learning targets 1. I can evaluate a laboratory procedure and analyze the data to form a conclusion 2. I can Set up an Inquiry lab by coming up with an investigative question and determining my needs for the lab.

Agenda Kick off question: What ideas do you have for your science fair project? 1. Heart rate lab conclusion should be turned in for a grade 2. Daphnia Lab conclusion turned in today 3. Set up for the effect of substances on organisms in our waterways 4. Learning log: What is a bioassay?

Water Contamination  How do we know what is “clean water?” In other words, how do we know if water is “safe” for humans and wildlife? Using Bioassays for Environmental Research4

Bioassays- notes Dose/Response Bioassays are used to: Estimate toxicity to humans. Estimate toxicity to humans. Estimate maximum concentrations of specific chemicals allowed to discharge into bodies of water. Estimate maximum concentrations of specific chemicals allowed to discharge into bodies of water. Investigate hazardous waste sites. Investigate hazardous waste sites.

Bioassay   A bioassay involves the use of biological organism to test for chemical toxicity. Canaries are used by coal miners as a way to test for high levels of methane (an odorless gas)

7 Bioassay Species 3 organisms are often used Daphnia Daphnia Duckweed Duckweed Lettuce Seeds Lettuce Seeds Expose organisms to chemicals and measure how they respond.

Used by the FDA   Bioassays are used to test drugs and skin care products before being “okayed” by the FDA.

Daphnia

Using Bioassays for Environmental Research10 CONCENTRATION VS. DOSE  LD 50 the Dose that is Lethal for 50% of the test organisms. Used for Daphnia Used for Daphnia  TC 50 the Concentration that causes a 50% drop in growth or health of the test organisms (Toxic Concentration). Used for seeds (they may not die, just not sprout) Used for seeds (they may not die, just not sprout)

An Introduction To Experimental Design  The Treatments in an experiment represent the factor that you vary while keeping everything else constant. Using Bioassays for Environmental Research11

An Introduction To Experimental Design  The control is the untreated group, used for comparison with the treatment groups. Using Bioassays for Environmental Research12

An Introduction To Experimental Design  Replicates are groups of organisms exposed to identical conditions. The more replicates the better. The more replicates the better. Using Bioassays for Environmental Research13