Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Scientific Process Unit Vocabulary Word Definition Example Observation Using the senses to study the natural world. Darwin drew pictures of finches in a journal before he made any scientific gain. Hypothesis A testable idea or explanation that leads to a scientific investigation If phosphate fertilizer from a lawn is washing into the river then the dwarf wedge mussels will die when exposed to high levels of phosphate in their water. Word Definition Example Prediction A logical statement about what will happen if the hypothesis is correct. Mussels will die when exposed to high levels of phosphate in the water. Experiment Procedure designed to test a hypothesis under controlled conditions. Testing the phosphate levels in the water. Variable A factor, trait, or condition that can be changed. Independent, dependent, and control Independent Variable *ON X-AXIS The variable that is manipulated or changed by the experimenter. The level of phosphate in the water. Word Definition Example Dependent Variable *ON Y-AXIS The effect / results / data. *WHAT IS MEASURED The number of mussels that survived versus died. Control Variable The variable that is unchanged. Same temperature. Experimental Group The group that receives the experimental treatment. The mussels that receive the phosphate in their water. Control Group Does not receive any experimental treatment. *MOST NORMAL CONDITIONS The mussels living in the water with no additional phosphate. Word Data Definition Example Information gathered Quantitative- numbers during an experiment. Qualitativedescriptions Correlation Associations between two or more events. Tree cookie or coral reef (see notes for description) Statistics Collection and classification of data that are in the form of numbers. Standard deviation, Chi- Square, T- score Mean The average. The average length of a mussels is 30 mm. Word Definition Example Distribution The pattern that the bars create when viewed as a whole. Bell curve Probability The chance that something will happen. ½ or 50% a penny will land heads up. Sample Group of individuals or events selected to represent the population. The scientists researched the same pod of 100 whales every summer for 10 years. Theory Broad explanation for a wide range of observations. Explain why. Theory of Natural Selection, the Cell Theory, the Germ Theory Word Definition Example Law Describes what nature does under certain conditions. Explains what will happen. Newton’s Laws of Motion Before we begin…. • • • • What does Biology mean to you? What does science mean to you? How do scientists make discoveries? List the steps of the scientific method how you remember them. Answer the questions using your prior knowledge How Scientists Observe the Natural World • 1. Observational- Typically uses quantitative and qualitative data. • 2. Controlled Study- Following the scientific steps. • 3. Literary Research Observational • http://video.ted.com/talk/podcast/2007/ None/DavidGallo_2007-480p.mp4 Controlled Study • http://www.ted.com/talks/sara_lewis_th e_loves_and_lies_of_fireflies Steps of the Scientific Method • • • • • • • • 1. Observation 2. Ask a Question 3. Hypothesis 4. Experimentation 5. Results / Collect Data 6. Analyze and Conclude 7. Repeat 8. Communicate results 1.____________ What you see, hear, taste, smell, and touch in the natural world. 2. ______________________ Why is it happening? What does it mean? 4. ____________ Design a procedure and test your hypothesis. 3.____________ A testable idea or explanation that leads to a scientific investigation. If and then statement. 5. ____________ Utilize data tables, mathematical equations, and graphs to represent the results collected. 6.____________ Look the data and relay to your audience, what is actually going on? What happened? What does the data say? 7.____________ Carry out the experiment again, double check your research / experiment. Observation • Science always begins with an observation! • Look at the pictures in the presentation and make as many observations as you can in five minutes. What do you see? Remember to use your senses! Observations can be made using descriptions, drawings, photographs, and measurements. https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja &uact=8&ved=0ahUKEwjL5vTJguTNAhWFGx4KHdM0CK4QjB0IBg&url=http%3A%2F %2Fwww.wri.org%2Fblog%2F2010%2F10%2Fhave-you-heard-coralbleaching&psig=AFQjCNFh277fhxVxUMb5nLzlrbKMuOr6aQ&ust=146807254784672 http://www.psmicrographs.co.uk/humanred-blood-cells-with-a-single-whitecell/science-image/80200668 http://www.ck12.org/book/CK-12Biology-Concepts/section/10.3/ https://www.tes.com/lessons/uSZ5Oewd USw_jg/symbiosis Pictures • • • • 1. Coral bleaching 2. Red blood cells with a white cell 3. Elephants spraying water on zebras 4. Crocodile with a bird- symbiosis Generate some questions! • What types of questions can you generate after looking at the pictures? • Ask a Question???? • Write two questions about the observations you made while looking at the picture. • 1.___________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ • 2.___________________________________________________ ____________________________________________________ ____________________________________________________ ____________________________________________________ Example we will be building on throughout this lesson • The students at Keene High School in New Hampshire, have observed that dwarf wedge mussels are disappearing from the Ashuelot River, near their school. Other observations the students have made is that the river looks polluted. • Write two questions that the students from Keene High School may have had after their observations. • 1.________________________________________ __________________________________________ __________________________________________ • 2.________________________________________ __________________________________________ __________________________________________ Let’s obtain some background knowledge about the mussels & pollution first! • It’s important to research the topic you are studying, this allows scientists to understand and brainstorm more efficiently. • Could result in generating more ideas and questions! • See notes for attachment. What is pollution or a pollutant? • Pollution- an undesirable change in the natural environment that is caused by the introduction of substances that are harmful to living organisms or by excessive wastes, heat, noise, or radiation. • Pollutant- substance or condition that contaminates water, air, or land. Two types of pollution Point Source Pollution • Pollution that comes from a specific site or a single source. • Examples- leaking septic tank systems, unlined landfills, water discharged by industries, public and industrial wastewater treatment plants, and leaking underground storage tanks that contain chemicals or fuels such as gasoline. Nonpoint Source Pollution • Comes from many different sources that are often difficult to identify. • 96% of waters in the US are polluted by nonpoint sources. • Examples- chemicals added to road surfaces (salt), water runoff from cities, pesticides, herbicides, fertilizers, feces, precipitation, soil runoff from farms, and oil / gas from personal watercrafts. Point Source Pollution http://oceanservice.noaa.gov/education/ kits/pollution/media/supp_pol03a.html https://www.fws.gov/southwest/es/New Mexico/EC_W_C101_1.cfm https://www.rivernetwork.org/eventslearning/resources/cwa-course/npdes/ Nonpoint Source Pollution http://pennsylvaniawatersheds.org/ourwork/nonpoint-source-pollution/ http://www.hillsdalecounty.info/ planningeduc0050.asp http://adventure.howstuffworks.com/outd oor-activities/water-sports/personalwatercraft3.htm http://georgiaorganics.org/wpcontent/uploads/2014/04/runoff_deadzo ne.png Common pollutants in water • Nitrogen and Phosphorus are naturally found in our environment. • All living things NEED nitrates & phosphates, they are important nutrients for growth and development, but TOO much can cause huge problems- Eutrophication • Phosphates- many come Some basicswe will cover from agricultural fertilizers, this topic in greater detail manure, and organic waste in in future sewage sections! • Nitrates- many come from runoff and fertilizers Writing a Hypothesis! 7 minute video: http://viewpure.com/lqk3TKuGNBA?start=0&end=0 • Hypothesis (If-Then- Because): • Hypothesis: A testable idea or explanation that leads to a scientific investigation. – Based off of many observations. – Tentative, testable, falsifiable. • Example: Phosphate fertilizer from a lawn is washing into the river and killing dwarf wedge mussels. • Prediction: a logical statement about what will happen if the hypothesis is correct. – A prediction is meant to describe what will happen in a specific situation (experiment). – Example: Mussels will die when exposed to high levels of phosphate in their water. • Do not use the words it, best, or better in your hypothesis! Try to be as specific as possible. • Try to avoid personal pronouns such as: you, me, we, I, etc. • Choose one of the items you are changing, and be clear on how it will compare with the other choices. • If- IV • Then- DV • Because- prediction / what you think is going to happen How animations help us study hypotheses! • http://www.ted.com/talks/janet_iwasa_h ow_animations_can_help_scientists_test_ a_hypothesis Turn the question into a hypothesis! • Directions: Write a hypothesis for the question and predict why you think that will happen. – Question 1- How does the amount of sunlight affect the growth of a plant? – Question 2- How does increased carbon dioxide affect the acidity of the ocean, specifically coral reefs? – Question 3- How does the amount of fertilizer given to a plant each day (none, required amount, or too much) affect how fast the plant will grow in 3 weeks? Question 1- Volunteer to the board! • If____________________________________________ _____________________________________________ _____________________________________________ ___________________________________________, then_________________________________________ _____________________________________________ _____________________________________________ _____________________________________________ because_____________________________________ _____________________________________________ _____________________________________________ _____________________________________________ ____________________________________________. Question 2- Volunteer to the board! • If____________________________________________ _____________________________________________ _____________________________________________ ___________________________________________, then_________________________________________ _____________________________________________ _____________________________________________ _____________________________________________ because_____________________________________ _____________________________________________ _____________________________________________ _____________________________________________ ____________________________________________. Question 3- Volunteer to the board! • If____________________________________________ _____________________________________________ _____________________________________________ ___________________________________________, then_________________________________________ _____________________________________________ _____________________________________________ _____________________________________________ because_____________________________________ _____________________________________________ _____________________________________________ _____________________________________________ ____________________________________________. Next step: Setting up an Experiment! • Experiment- procedure designed to test a hypothesis under controlled conditions. • Designed to pinpoint cause and effect relationships. • You want to have two variables: a tested variable and a control. • The tested variable =_Independent variable, YOU control it,YOU manipulate it. Who controls it? I DO! – Example: level of phosphate in the water. – In order to study one variable, scientists usually study two groups at one time: the one you are changing and the one that stays the same. • The experimental group: the group that receives the experimental treatment. – Example: the mussels that receive the phosphate in their water. • The control group: does not receive any experimental treatment. – Example: the mussels living in the water with no additional phosphates. • The effect / results= Dependent variable, it depends on the IV. Dependent =data See Variables Graphic Organizer Variables Independent Example dependent Example Control Example Results / Data Collection • Keeping careful and accurate results is extremely important. • Data: information gathered during an experiment. Qualitative Data Quantitative Data -Quality -Descriptions -Quantity -Amounts -Numbers • Organized into tables and graphs. Scientists also use the metric system when collecting and converting data. • Visual representation allows scientists to explain the data clearly to others. • Graphs allow scientists to display relationships between variables, as well as illustrate conclusions drawn from an experiment: bar, line, and circle graphs are the most commonly used. Let’s Practice Analyzing Data Tables General Rules for Graphing • Always label the X and Y axis. – X- horizontal and is also the Independent Variable (IV) – Y- vertical and is also the Dependent Variable (DV) – Write out units (mm., cm., km., etc) – Label the axis with the correct variable. • Create a comprehensive title that explains your graph. – It must explain what you are comparing! • Increments / Scale – Create a clean, even scale. Example- 2, 4, 6, 8, 10 – Data points should fill the graph. Use the entire graph, this will ensure that you can accurately read and see what the graph is telling you. • Count up how many boxes you have (how many increments there will be). • Determine how much data space you need to span (find the lowest and highest data value). • Calculate which increment size will allow you to span the space, increase by a constant rate, and allow for accurate data points (divide highest data by # of spaces). Always round up! • Always graph in pencil. • Create a key if there are multiple sets of data. Histograms • A series of columns representing a variation in frequency (the number of times an event occurs) of a variable over a discrete interval or class. http://www.saburchill .com/IBbiology/grap hs/009.html The distribution of the number of flowers per flower head in a population of red clover, Trifolium repens Practice Problem A manager at Taco Bell is interested in the distance her employees travel to work each day. She asked each employee how many kilometers the store is from his or her home and received the following answers: 1 18 4 9 9 2 7 16 11 18 6 3 4 12 8 7 15 5 1 8 12 15 8 9 4 13 4 6 2 14 2 17 5 10 7 6 1 18 11 3 9 14 5 4 2 5 5 2 10 6 In order to organize this data, complete the following frequency distribution and construct a histogram. After you have graphed the histogram, calculate the relative frequency. For relative frequency, take the frequency and divide it by the total number. For example, if there are 10 employees that travel 1-3 km. out of 50, 10/50 = .20 Kilometers Frequency 1-3 10 4-6 7-9 10 - 12 13 - 15 16 - 18 Total Relative Frequency .20 In order to organize this data, complete the following frequency distribution and construct a histogram for this data. After you have graphed the histogram, calculate the relative frequency. For relative frequency, take the frequency and divide it by the total number. For example, if there are 10 employees that travel 1-3 km. out of 50, 10/50 = .20 Kilometers Frequency 1-3 10 Relative Frequency .20 4-6 14 .28 7-9 10 - 12 10 6 .20 .12 13 - 15 5 .10 16 - 18 5 .10 Total 50 100 The distribution of employees that travel different distances to work at Taco Bell 16 14 12 10 Total number 8 of employees 6 4 2 0 1 to 3 4 to 6 7 to 9 10 to 12 13 to 15 16 to 18 Kilometers traveled (km.) Relative Frequency Relative Frequency 0.3 0.25 0.2 0.15 0.1 0.05 0 1 to 3 4 to 6 7 to 9 10 to 13 to 12 15 Kilometers traveled (km.) 16 to 18 Bar graphs: compare data of several things in one graph. – Create a bar graph using the students data obtained from their experiment. • Pollutant concentrations (mg /L) in the water Site Nitrates Phosphates 1 0.3 0.02 2 0.3 0.06 3 0.1 0.07 Pollutant concentrations (mg /L) in the water Concentration (mg/L) 0.35 0.3 0.25 0.2 Nitrates Phosphates 0.15 0.1 0.05 0 1 2 Site 3 What does the data show? • Look at the bar graph and describe, in words, what you see. • Record. Bar graph analysis • Site three has a higher level of phosphates and a lower level of nitrates. • Think deeper- what can you do with this information? Line Graphs • Show changes over time. • Interpolation is when we use a line or curve of best fit to make a judgment about what a value would be between two known points or measurements. • Extrapolation is when we use a line or curve of best fit to make a judgment about what a value would be beyond the last known point or measurement. Make a line graph with the data below The heating of a pot of water on a stove. Change in temperature over time 100 90 80 70 60 Temperature 50 (Celcius) 40 30 20 10 0 1 2 3 4 5 6 7 Time (minutes) 8 9 10 11 Circle Graph • Percentages • Graph the data. Inventions Teens Can't Live Without Other 2% Toothbrush 34% Personal Computer 16% Automobile 31% Cell Phone 10% Microwave Oven 7% Data Collection & Results: statistics, averages, distribution, probability, and the metric system • Statistics- collection and classification of data that are in the form of numbers. – Many scientists use statistics to measure populations. • Example- 14 dwarf wedge mussels that were sampled are part of all dwarf wedge mussels on the Ashuelot River. Mean • Mean- the number obtained by adding the data for a characteristic and dividing this sum by the number of individuals. – Scientists can compare different populations by comparing their means. – Example- measuring the length of all of the mussels and then dividing it by the total number, this provides us with the average. Average length of a mussel is 30 mm. – Practice- Calculate the mean of the data. Answer • 8.7 Distribution • The pattern that the bars create when viewed as a whole. - Lengths of individuals are between 15 mm. and 50 mm. - The line connecting the tops of the bars forms the shape of a bell. - This graph is a typical bell curve, the mean is directly in the middle= bell shaped curves are referred to as normal distribution. Probability • The chance that something will happen. – Example- chance of getting heads when you toss a penny. • ½, 50%, .5 – When writing probability, the number is usually expressed as a number between 0-1 and written in decimal form. – Situation- a penny is tossed 10 times, and 7 /10 times it lands on heads. Does this result prove that the probability of a penny coming up heads is .7 or 70%? • The answer is NO! Why? The sample size is too small to provide an accurate result. • Sample- group of individuals or events selected to represent the population. • Scientists try to make sure that the samples are large enough to provide an accurate estimate for the whole population Practice Problem • You are in a forest and count 200 pine trees and notice that 40 of those trees have pine cones. What is the probability that the next pine tree you come across will have pine cones? Answer • 40/200= .20 The Metric System • When we collect data in science, the metric system is used. – Based on the power of 10. – French came up with it. – Every country uses it, except ours Measure Base Unit Equals about Length 1 Meter 3.28 feet (ft.) Mass 1 Gram Volume 1 Liter Weight of a paperclip Just less than 3 cans of soda. Temperature 0 Celsius Snow! Common conversions: 1 inch= 2.54 cm. 1 kg.= 2.2 lbs. 1 cm = 10 mm. 1 L= 1.06 quarts 1km. = .62 miles 1 ml. = 1 cm3 1 m. = 3.28 feet 1 fathom = 6 feet 1 mile= 5,280 ft. = 1609.8 m. Degrees Fahrenheit = (9/5 X degrees C) + 32 Degrees Celsius = 5/9 X (degrees F - 32) Ko= Co + 273 Practice Temperature Conversions Convert the following to Fahrenheit Convert the following to Celsius Convert the Convert the following to Kelvin following to Celsius 1) 10o C ________ 2) 30o C ________ 3) 40o C ________ 4) 37o C ________ 5) 0o C ________ 6) 32o F ________ 7) 45o F ________ 8) 70o F ________ 9) 80o F ________ 10) 90o F ________ 11) 212o F ________ 12) 0o C ________ 13) -50o C ________ 14) 90o C ________ 15) -20o C ________ 16) 100o K ________ 17) 200o K ________ 18) 273o K ________ 19) 350o K ________ Practice Temperature Conversions- Answers Convert the following to Fahrenheit Convert the following to Celsius Convert the Convert the following to Kelvin following to Celsius 1) 10o C ____50____ 2) 30o C _____86___ 3) 40o C ___104_____ 4) 37o C _____98.6___ 5) 0o C ____32____ 6) 32o F ____0____ 7) 45o F _____7.2___ 8) 70o F ____21.1____ 9) 80o F ___26.7_____ 10) 90o F _____32.2___ 11) 212o F _____100___ 12) 0o C ____273____ 13) -50o C ______223.15__ 14) 90o C ____363.15____ 15) -20o C ___253.15_____ 16) 100o K 173.15 17) 200o K _-73__ 18) 273o K __0______ 19) 350o K ____77____ Mnemonic Device King Henry Died By Drinking Chocolate Milk Base Unit: Meter Gram Liter Copy notes from the board! Conversion Answers! 1. 2. 3. 4. 5. 6. 7. 8. 9. kg. m. g. mL. mm. L. km. cm. mg. • • • • • • • • • • • • • • • 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 2 g. 104,000 km. 4.80 m. 5,6000 g. .80 cm. 5,000 mL. .20 kg. .08 L .50 m. 560 cm. 160 mm. 2.50 km. 65,000 mg. 63 mm. .12 g. Analysis & Conclusion • Scientists take their results and analyze them / figure out what they mean. • Scientists can use mathematical tools to help determine if their research is significant or not. • Scientists compare the outcome of their experiment with their predictions. • Sometimes the conclusion is obvious and sometimes it is not obvious. Example – Example- in the mussel experiment, what if three mussels died in the control tank and five died in the phosphate / experimental tank? There is not a big enough difference in the data; therefore, the students could not conclude that the phosphate fertilizer is killing the mussels. – How would you fix this or change this issue? ______________________________________________ ______________________________________________ ______________________________________________ ______________________________________________ Repeat & Communicate Results • Scientists do not publish their results right away; they look for a large amount of supporting evidence. • Supporting evidence is achieved via duplication. • Duplication means that they are conducting or carrying out their experiment several times. The more an experiment is repeated, not only by the lead scientist, but also by others around the world, the more reliable the conclusion. Why is duplication important? Duplication • Catch and fix mistakes. • Double check results- make sure they obtain the same answer. • Adds validity. • Once the experiment has been duplicated and the results are deemed important, the scientist can then publish their results in a scientific journal. What about the questions that cannot be studied experimentally? • Some questions cannot be studied. – Example: What was the Earth’s climate like 60 million years ago? Why? ____________________________________________ ____________________________________________ ____________________________________________ – Example: Does smoking cause lung cancer in humans? Why? ____________________________________________ ____________________________________________ ____________________________________________ The Why’s?? • 1. Scientists are 60 million years too late. • 2. Experiments that might injure people are unethical. How do scientists study questions such as the latter? – Correlations: look at associations between two or more events. Example 1- Tree Cookies • Scientists know that the relative width of a ring on a tree trunk is a good indicator of the amount of rainfall the tree received in a given year. Wide rings= rainy years, narrow rings= dry years. Scientists have used tree rings to investigate populations of early settlers in the United States. In some places where settlers disappeared, scientists have found that during that time the tree rings were very narrow, which could mean that food was hard to grow, potentially leading to starvation. Example 2- Coral Reefs • Corals grow a layer of skeleton every year, with some living up to 300 years. There is a specific ratio between the two elements (strontium and calcium) that make up the skeleton and correlate the ratio with the sea surface temperatures, allowing scientists to see how the Earth’s climate has changed over the centuries. How do scientists come up with questions? • Curiosity- Jane Goodall, studied chimpanzees in the Gombe Forest in Tanzania for years, even lived along them in their natural habitat. Through continual observation, she started recognizing and learning their behaviors, interactions, and group dynamics. This created a plethora of research papers and changed the way people perceived these magnificent creatures. She is now one of the most successful woman scientists in history. • https://www.youtube.com/watch?v=PmcNWJpIX p8 • Skepticism- scientists don’t believe everything they are told. • Openness to new ideas- keep an open mind about how the world works. • Intellectual Honesty- after duplicating the results, a good scientist will consider the possibility that the new results may be accurate, even if this means that the hypothesis might be wrong. • Imagination and Creativity- constantly coming up with new ideas and questions. Many of the new questions come from previous research, building on something that is already there. – Example- John Snow, a London scientist, created a famous spot map of all of the people that had died of cholera, a potentially fatal disease caused by a bacterium found in water that has been polluted by human waste. Many people had poor plumbing or lack of plumbing; therefore they got their water from public water pumps. By creating a spot map, Snow was able to pinpoint which pump was causing the cholera epidemic, and the town was able to shut it down. Now let’s read about John Snow and how he used the scientific process to build upon his hypothesis! Is it a theory or a law? Theory Law Theory • Broad explanation for a wide range of observations. • Explains WHY something happens. • Concise, applicable, systematic, and analytical. • Examples: theory of natural selection, germ theory, and the cell theory. Scientific Law • Describes what nature does under certain conditions. • Explains what will happen. • Statements about an observed phenomena. • Often mathematically supported. • Predictable outcomes. • Example- Newton’s Laws of Motion Both • Based on tested hypotheses. • Supported by a large amount of experimental data. • Widely accepted by scientists. • Can be revised. Technology in Science • Scientists use a variety of tools and technology when conducting research. • Let’s name as many scientific tools that you have used in the classroom or in a lab. • Technology continually changes the way scientists work. • Common types of technology used in Biology – Microscopes: Compound Light, Dissecting Scope, Scanning Electron (SEM), and Transmission Electron (TEM). – Medical Imaging: • X-rays: observing the skeleton. • MRI’s- uses a strong magnetic field to produce a cross section image of a part of the body. Shows the soft and dense tissues in detail. – Models- physical replicas, such as a heart or brain. – Computer Models- computer have allowed scientists to take research to a whole new level. • Example- how medicines impact the body. • Example- what the heart activity looks like during a heart attack versus a normal heartbeat. • Can predict how fast and far the flu virus can spread in a city. • Discovered that water molecules must move in a specific way in order to enter a cell channel. Water is the only molecule that has a specific fit that other molecules can’t match. • The entire human genome has been figured out. The Human Genome Project was completed in April of 2003. • Really utilized when actual experiments can’t be done, because they may be unethical, impractical, or simply unsafe. • Molecular Genetics- the study and manipulation of DNA on a molecular level. It’s used to study evolution, ecology, biochemistry, anatomy, etc. –Biotechnology- the use and application of living things and biological processes. • Using microorganisms to make bread and cheese. • DNA testing to free people wrongly accused of crimes. • Great potential to solve a lot of problems: alternative energy. • Stem Cell research • Cloning – The production of identical copies of genes. – Dolly the sheep in 1997. • Genetic screening – Analyzing a person’s genes to identify genetic variations. – Allows us to analyze the DNA of our offspring, and to see if there are any potential disorders or diseases. There are many benefits, as well as biological risks, and is debated frequently • Almost all domestic plants and animals are the result of selective breeding, where humans have manipulated their DNA. –Transgenic- organisms that have genes from more than one species, or have altered copies of their own genes. »Examples: • Genetically Modified Foods / AKA GMO’s (corn, canola, soy). • Transgenic bacteria can make human insulin to treat people with diabetes.