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Bellringer ! 8/26/19 – Jane Goodall ! ! Describe how Jane did discovery science. ! ! How is the way Jane did science different from that of a typical science lab?
! Watch first 12 minutes of Jane documentary
Bellringer ! 8/28/19 –Fortune Telling Fish? ! Directions: ! Open your fortune telling fish and put it in your hand and observe
what happens. What does the packaging say this means about your personality?
! One criteria for scientific thought is that all phenomena have NATURAL causes or explanations.
! Discuss with your team some natural cause that could explain the fish’s movements.
! ! WRITING: ! Choose one of the causes your group suggested. ! Write a hypothesis that predicts the cause for the fish’s movements. ! Briefly describe a way you could test your hypothesis.
Bellringer: 9/3/19 -‐ Lab Safety
⚫ 7. As you are watch the UC Lab Safety Video write down 3 lab safety standards presented.
⚫ UCLA Lab Safety Video
Bellringer 9/4/19 –Scien9fic Methods ! Put the following steps in order.
! Question ! Hypothesis ! Prediction ! Test ! Observation
! What are the key elements to a good hypothesis? ! What are the two outcomes of a scientific test?
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Bellringer: 9/5/19-‐ Variables ! 1. What are the 3 Types of variables? Give an example of each using the mimicry (snake) experiment.
! 2. Compare and contrast the two groups in a scientific experiment. Use a Venn diagram to do this.
The Science of Biology
Unit 1
Biology ! Science is a quest to understand nature
! It includes elements of surprise, challenge and adventure
! Careful planning, reasoning, persistence, patience, set-backs and tiny steps of progress also mark the path of science
! In this chapter you will learn how science works and how you can use the process of science to help answer your own questions
Biology ! Biology - the scientific study of LIFE ! Biology blends 2 main forms of scientific exploration:
! Discovery science ! Mostly about describing nature
! Hypothesis-based science ! Mostly about explaining nature
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What is Biology? – 5 Unifying Themes Life through photographs
Inquiry and Observation ! At the heart of science is inquiry:
people asking questions about the world around them and seeking answers
! Why does a house plant grow toward the light?
! How does it sense the direction of the light?
! What enables the plant to bend toward the light?
! What direction would the plant grow in the dark?
Inquiry and Observation ! More that just asking questions.
! Inquiry - the process of investigation, with a thoughtful question, leading to a search for answers.
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Observations and Data ! The questions that drive scientific inquiry are based
on observations. ! Observation - the use of the senses to gather and
record information about structures or processes. ! Sight ! Sound ! Smell ! Touch ! Taste
Observations and Data ! Recorded observations are call data.
! Put another way, data are forms of information ! Pencil marks on a door frame recording a child’s height and
growth are data ! Carefully recorded observations in a field journal about
chimpanzee are data ! A chart with the yearly rainfall recorded is data
Observations and Data ! All observations depend on human senses. ! Today’s data is often collected using technology. ! Many times our senses are limited and we need help ! Examples:
! Telescopes ! Microscopes ! Seismographs ! Scales ! Thermometers ! Etc.
Data Collec9on ! Two types of data: Qualitative and Quantitative
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Data Collec9on Qualitative Data ! Qualitative -‐ descriptions in
words ! QUALITIES ! Ex: Viscous liquid, Brown pigment
Quantitative Data ! Quantitative – numeric
measurements ! QUANTITIES ! Ex: 10 seconds, 30 feet, 98.6° Fahrenheit
Observations and Data ! Data can best support science when it is clearly
organized, consistently recorded and reliable. ! Ex: Charts , graphs, tables
Inferences in Science ! A logical conclusion based on observations is called an
inference. ! A person makes an inference by relating observations to
prior knowledge
Observation + Prior knowledge= inference(logical conclusion)
Inferences in Science ! What do you observe happening in this picture? ! What can you infer?
Mold
Bacteria
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Inferences in Science ! It is important not to
confuse inferences with the observations on which they are based. ! Observation: hearing
the door bell ring ! Inference: some one
is at the door ! You are not observing
that someone is at the door!
Bias ! Experimenter’s bias – is leaning towards a result expected by the human experimenter. ! Also known as research bias ! Occurs when scientists unconsciously affect outcome of the experiment. ! in reading-‐up on the field ! in specifying and selecting the study sample ! in executing the experimental procedure ! in measuring exposures and outcomes ! in analyzing the data ! in interpreting the analysis ! in publishing the results.
Bias Neil deGrasse Tyson on Bias Some Descrip9ve Adjec9ves ! Depth: deep, full, shallow, empty, endless, infinite, steep ! Height: tall, short, small, vast, spacious, big, large, gigantic, tiny, huge, little, enormous, petite,
miniature, massive, mammoth, mighty, microscopic, medium, colossal ! Width: wide, thick, broad, narrow, thin, slender, skinny, slim, bulky, baggy, bulging ! Weight: heavy, light, strong, feathery, fat, stocky, stout, lean, skinny, slim, slender, crowded, trim,
lithe, plump, chunky ! Shape: circular, curved, crooked, curly, diamond-‐shaped, flat, jagged, oval, pointed, round,
rectangular, spiral, square, triangular, angular, arched, bell-‐shaped, bent, coiled, cone-‐shaped, conical, cylindrical, dome-‐shaped, egg-‐shaped, elliptical, erect, flat, flat, forked, geodesic, heart-‐shaped, hexagon-‐shaped, hollow, level, molded, oblong, obtuse, octagonal, pentagon-‐shaped, pyramidal, rambling, scalloped, straight, symmetrical, tunnel-‐shaped, upright, amoeba-‐like
! Sounds: barking, crackling, crying, dripping, echoing, fluttering, giggling, hissing, howling, jingling, knocking, laughing, moaning, neighing, popping, quarreling, ringing, roaring, sizzling, swishing, tapping, thumping, whistling, yelling
! Textures: blunt, brittle, coarse, crumbly, dense, flexible, fluffy, glossy, gritty, jagged, mushy, pebbly, prickly, tough, wrinkly, rocky, rough, scaly, shaggy, sharp, silky, slimy, smooth, soggy, spongy, springy, squishy, thorny, velvety
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Mystery Vial Lab -‐ answers ! 1-‐ Marble ! 2-‐ 6 Canadian dollars ! 4-‐ Nails ! 3-‐ A different grape lipstick ! 6 – Steel cut oats (oatmeal) ! 7 – 5 hair bands ! 8-‐ banana boat sun tan oil ! 9-‐ potting soil ! 10-‐ Cherry Jello Powder ! 11-‐ sesame seeds ! 12 – garlic salt ! 13 – vanilla extract ! 14-‐ cinnamon ! 15-‐ apple cider vinegar ! 16 – tarragon vinegar ! 17 – nail polish remover ! 18-‐ pickle juice ! 19 – loose peach tea ! 20 – Very Green juice smoothie
! 21-‐ balsalmic vinegar ! 22-‐ Cumin ! 23-‐kosher salt ! 24 – Cayenne extract ! 25 – Coffee grounds ! 26 – soy sauce ! 27 – cherry juice ! 28 – bread crumbs ! 29-‐ mustard ! 30-‐ baby oil ! 32 -‐ bolts ! 34 – nail polish remover ! 36 – Neutrogena pink grapefruit face scrub ! 37-‐ tea tree oil foot scrub ! 44 – Curry powder ! 45 – Caladryl lotion ! 46 – Listerine mouth wash
Hypothesis-Based Science is a Search for Explanations ! Its one thing to observe and record, but what causes
the phenomenon is another
Methods of Hypothesis-based Science ! “Scientific Method”- ideal method, but not always a
structured step by step process. ! Science is actually less structured than most people
realize ! Despite this, there is one key element in HBS- the
hypothesis
Forming and Testing a Hypothesis ! Hypothesis - a suggested answer to a well-defined
scientific question ! Its an explanation on trial ! Allows you to make certain predictions that scientists
can test! ! No experimental evidence at this point. ! Must be specific and testable!
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Forming and Testing a Hypothesis ! People use hypothesis instinctively, its natural
! Observation: the flash light doesn’t work ! Question: What’s wrong with it?
Hypothesis: The Batteries are dead.
Prediction: If the batteries are dead and you replace them with new ones, then the flashlight will work.
Test: Replace the batteries.
Forming and Testing a Hypothesis ! The inquiry continues with test of
alternative hypothesis. ! Next test?
! Replace the bulb ! Test the switch ! Test the wire connections
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2 Outcomes of Scien9fic Inquiry ! 1. Non-‐significant: The data show no effect, or such a small effect it could have happened due to chance. ! Hypothesis is NOT SUPPORTED/REJECTED ! Come up with a new hypothesis
2 Outcomes of Scien9fic Inquiry ! 2. Statistically Significant: Data shows an effect that is likely not due to chance ! Hypothesis IS SUPPORTED
A Case Study in Hypothesis-‐Based Science ! Case study: an in-‐depth examination of something that really happened ! Law students train by analyzing actual documents of past cases
! Case studies in science are posted in scientific journals and can boost your understanding of scientific method
From Observa9ons to Ques9on and Hypothesis ! It all begins with observations
! Case study example: Mimicry (Flower-‐fly and honey bee) ! Many poisonous animals are brightly colored with distinctive markings
! These serve as a warning to predators
! There are also mimics or imposters. They looks like a poisonous species but are harmless
! Question: What is the function of such mimicry
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From Observa9ons to Ques9on and Hypothesis ! Hypothesis:
! Mimics benefit because the predators confuse them with the actual harmful species
Tes9ng a Predic9on of the Hypothesis ! In 2001 scientists designed a simple but clever way to test this hypothesis on look-‐alike snakes ! Eastern coral snake: venomous ! Scarlet king snake: harmless
Tes9ng a Predic9on of the Hypothesis ! The hypothesis predicts that predators will attack snake with bright red, yellow, and black rings less frequently than species lacking these warning markings.
! To test this, researchers made hundreds of artificial king snakes out of wire and plasticine. ! Two types of snakes made:
! Snakes with black, yellow and red rings ! Plain brown snakes
Designing a Controlled Experiment ! Why did the experiment include artificial snakes that were plain brown? ! Contrast in color was needed to see if predators attack snakes based on their color.
! If all snakes were the same, the number of attacks would indicate nothing about the effect of colored rings
! If you want to test the effect of one condition, you need to provide a contrasting condition as well
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Tes9ng a Predic9on of the Hypothesis ! Researchers placed equal numbers of both types of artificial snakes throughout North and South Carolina
! Four weeks later the snakes were retrieved ! They counted how many had been attacked by looking for bite or claw marks
! Most common predators: foxes, coyotes, raccoon, some black bears
Designing a Controlled Experiment ! A condition that can differ within an experiment is called a variable. ! In the artificial snakes, the variable is the presence versus the absence of the colored rings.
! Most often experiments test the effect of a difference of just one variable.
! An experiment that tests the effect of a single variable is called a controlled experiment.
Types of Variables Independent Variables
Dependent Variables
⚫ In an experiment it’s the condition that is manipulated or changed, BY THE SCIENTIST.
⚫ The variable that is observed and measured in an experiment. ⚫ They depend on the
independent variable.
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Designing a Controlled Experiment ! Controlled experiments try to eliminate or control other variables that could affect the outcome. ! Called Constants. ! Not simple ! Variables like weather or temperature could influence predator behavior in the snake experiment
! In an ideal setting (a laboratory)-‐ climate and temperature can be controlled
! This impossible in field experiments
Pasteur -‐ Spontaneous Genera9on Constants?
Elimina9ng Unwanted Variables ! How do we get rid of unwanted variables? ! Researchers divide the subjects (artificial snakes in this example) into 2 groups. ! Control group – NOT exposed to the EXTRA (Independent Variable) factor.
! Experimental group – has the EXTRA (Independent Variable) factor
Elimina9ng Unwanted Variables ! The experiment was testing the effect of colored rings so the experimental group was the colored ringed snakes.
! The brown snakes served as a control group showing what happens in the absence of colored rings
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Elimina9ng Unwanted Variables ! Everything about the 2 snake groups was the same…the constants. ! Both made of the same material ! Both placed at random in the same locations ! Conditions such as light, temperature, and appetite of predators varies, but both groups were subject to the same variation
! Thus color was the only consistent difference or variable between the groups
! So any difference in attack rates between the groups could be attributed to color and no other variable
“If…,then…” Reasoning
! Snake case study ! same reasoning as flashlight example.
Organizing and Interpre9ng Data ! Experiment is not over after data collected
! Often results don’t make sense until after much analysis of data
! For quantitative data it helps to put it in a table or graph, this may reveal a pattern that you could not see in the raw data
Evidence ! Evidence consists of a collected body of data from observations and experiments.
! Scientific evidence should be repeatable. ! Repeating observations and experiments of others should lead to similar evidence.
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Peer Review ! Experimental methods and results are evaluated by other scientists.
Science is limited ! Science is limited in the kinds of questions it can answer
! Only able to search for natural causes for natural phenomena
! Supernatural explanations of natural events are outside of the bounds of science, there is no way to show they are false
Hypothesis ! Scientific hypotheses should lead to predictions that can be tested.
! Some experiment must be able to reveal if hypothesis is false.
! Even hypothesis that stand up to repeated testing may be later revised or rejected
Language of science ! Turn to page 8 of your notes packet ! Use the list of prefixes and suffixes to define the words 1-‐20
! Use the list of prefixes to make up a new word ! Define your new word
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Theories ! A theory is a well tested explanation that made sense of a great variety of scientific observation. ! much broader in scope than hypothesis ! lead to major scientific advances ! Only accepted in science when supported by large body of experimental evidence.
! Can be modified or discarded due to new evidence
Theories ! Germ theory
! mid 1800s illness was thought to be due to imbalances in the bodies “humours” or fluids
! Research suggested it was due to microscopic organisms, such as bacteria.
! Once stated that disease causing microorganisms must be able to grow in a lab ! Prions and viruses do not fit this theory, so it has been changed as new evidence comes to light.
Louis Pasteur
Cell Theory & Germ Theory Draw the following table on the 3 x 5 card
Fill in the table as you view the videos.
Cell Theory What do they have in
common?
Germ Theory
Details: Details:
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Scien9fic Law ! Scientific law describes a statement or equations that reliably predicts patterns or events in nature. ! Ex: Law of conservation of energy – energy may change form but it cannot be created nor destroyed
! It does not provide an explanation…theories do provide explanation.
Communica9on ! Communicating findings is important in science
! Allows scientists to check each other’s claims by repeating each other’s investigations
! Validation
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Technology ! Technology and science are related, but their goals and methods are different
! Goal of science: understand nature
! Goal of technology: to apply scientific understanding for some specific purpose
Imaging technology ! Microscopes provide new views of life
! Light microscope –1500 x magnification, can view living or preserved specimens
! Scanning electron microscope (SEM) – 100,000 x magnification, can only view preserved specimens in a vacuum ! Bounces electrons off the surface to make a 3D image
! Transmission electron microscope (TEM) – 100,000 x magnification, can only view preserved specimens in a vacuum ! Transmits electrons through a specimen to make a 2D image
Medical Imaging ! X rays – X rays pass through soft tissue but are blocked by bone and teeth.
! MRIs – Magnetic Resonance Imaging – uses a strong magnetic field to produce a cross section image of part of the body. ! Good for soft tissue. ! fMRI (functional) can show activity in tissue.
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Models ! Models are physical, mental, or mathematical representations of how people understand a process or an idea ! Help explain and evaluate the natural world
Computer Models ! Complex systems are modeled on computers ! Epidemiology – how diseases spread
! How medicines might affect the body.
Bellwork 9/9 ! 9. Why are models used in science? Give a specific example of when a model could be used.
! 10. How are the goals of science and technology different?
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Molecular gene9cs ! Gene – segment of DNA that stores genetic information
! Molecular genetics -‐ study and manipulation of DNA on a molecular level. ! Transgenic plants and animals ! GMO’s (genetically modified organisms) ! Gene replacement
! Genomics – study and comparison of genomes (entire DNA map) within and across a species.
Demonstrates the possibility of changing the genetic makeup of cells to prevent the body’s rejection of transplanted organs.
Biology and your Health ! Food related causes of illness.
! Food poisoning ! Mad cow disease ! Food allergies
! Biology helps us assess these issues ! Sunscreen ! Exercise ! Drug and alcohol use
Biology and the World Around you ! Amphibian Deformities (1995, Minnesota)
! Causes? ! Chemicals in the water ! UV radiation ! Infection (trematodes) ! Predation
! How could biology help you to better understand environmental issues?
Biotechnology
! Biotechnology – use and application of living things and biological processes. ! Microorganisms make bread and cheese
! DNA testing to free a criminal ! Transgenics -‐ transferring genes from one organism to another.
! GMO’s ! Insulin making bacteria
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Unanswered ques9ons ! Benefits and Ethical Considerations ! Genetic screening
! Structure of DNA was described in 1953, mapped by 2003. ! Can cancer be prevented or cured? ! How do viruses mutate? ! How are memories stored? ! Life on other planets?
! Lots of unanswered questions still exist today!!
Unifying Themes of Biology ! 1. All levels of life have systems of related parts
! 2. Structure and function are related in biology
! 3. Organisms must maintain homeostasis (internal balance) to survive in diverse environments
! 4. Evolution explains the unity and diversity of life.
Theme #1: All levels of life have systems of related parts ! System is an organized group of related parts that interact to form a whole. ! Smallest – molecules ! Largest – biosphere
! Ecosystem – physical environment with different species that interact with one another and with nonliving things.
Theme #2: Structure and Func9on are related in Biology ! Examples
! Car parts have specific functions
! Body parts have specific functions
! Molecules have specific functions
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Theme #3: Organisms must maintain homeostasis to survive diverse environments ! Homeostasis – the maintenance of constant internal conditions in an organisms ! Temperature ! Blood sugar ! Acidity
! Breakdowns in homeostasis are often life threatening.
Theme #4: Evolu9on explains the unity and diversity of life ! Adaptation – an inherited trait that gives an advantage to individual organisms and is passed on to future generations. ! Evolutionary adaptations are different than adapting by choice.
! Unity and Diversity – Evolution accounts for both of these ! Humans and bacteria – both have DNA and RNA, same sources of energy, similar cell structures.
Characteris9cs of Life ! All living things have the following in common
! 1. Cells – the basic unit of life ! 2. Need for energy ! 3. Response to environment – to survive ! 4. Reproduction and development
! Reproduce – pass on genetic material (DNA) to offspring ! Develop – mature to be able to reproduce
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Extra IV and DV Prac9ce ! On following slides….. ! Students watched a cartoon either alone or with
others and then rated how funny they found the cartoon to be.
! Independent Variable:
! Dependent Variable:
! A comprehension test was given to students after they had studied textbook material either in silence or with the television turned on.
! Independent Variable:
! Dependent Variable:
! Some elementary school teachers were told that a child’s parents were college graduates, and other teachers were told that the child’s parents had not finished high school; they then rated the child’s academic potential.
! Independent Variable:
! Dependent Variable:
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! Workers at a company were assigned to one of two conditions: One group completed a stress management training program; another group of workers did not participate in the training. The number of sick days taken by these workers was examined for the two subsequent months.
! Independent Variable:
! Dependent Variable:
! Students at a University were split into two groups and each received a different text for a philosophy course. Once group received a traditional text book, while the other received an interactive textbook on a tablet computer. After the course, the final exam marks between the two groups of students was compared.
! Independent Variable:
! Dependent Variable:
Design an Experiment ! Eating breakfast in the morning increases the ability to learn in school.
! IV: ! DV:
Design an Experiment ! Drinking energy drinks makes people more aggressive.
! IV: ! DV: