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Chapter 1 The Science of Biology.

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1 Chapter 1 The Science of Biology

2 1-1 What is Science? Objectives: State the goals of science
Describe the steps used in the scientific method

3 Goal of science The world around us can only be explained by that which we can observe To investigate and understand nature To explain events in nature Use those explanations to make useful predictions

4 Science Can Change Ideas
Science- organized way of using evidence to learn about the natural world It’s a process! Term can also refer to the body of knowledge scientists have built up after years using this process Some ideas or “facts” will change in time

5 Scientific Methodology
Involves observing, asking questions, making inferences and forming hypotheses, conducting controlled experiments

6 Scientific Method Make Observations Analyze Results Form a Hypothesis
Draw a Conclusion Set Up a Controlled Experiment Publish Results Record Results

7 Scientific Method Observation- the act of noticing or describing events or processes in a careful, orderly way gather information using one or more of the senses

8 Scientific Method Inference-logical interpretation based on prior knowledge and experience Inferences can inform hypotheses

9 Observations vs. Inferences
Statement Observation Inference Object A is round and orange. X Object A is a basketball. Object C is round and black and white. Object C is larger than Object B. Object B is smooth. Object B is a table-tennis ball. Each object is used in a different sport.


11 Scientific Method Hypothesis- a scientific explanation for a set of observations that can be tested in ways that support or reject it

12 Formulating a Hypothesis
Mystery Worms A teacher collected some beetles from a rotting log and placed them in a container of dry oatmeal in her classroom. She kept the box covered with a light cloth so that the beetles could not escape. She also asked one of her students to add potato and apple pieces once a week to provide food and moisture for the beetles. After several weeks, the student reported that there were some strange-looking, wormlike organisms in the container. 1. Formulate a hypothesis that might explain the presence of the “worms” in the container. 2. How could you test your hypothesis?

13 Scientific Method In order to have a controlled experiment, only one variable can be changed at a time All other conditions should be kept unchanged or controlled Independent (manipulated) variable- variable that is deliberately changed Dependent (responding) variable- variable that is observed and changes in response to the independent variable

14 Scientific Method A controlled experiment typically consists of a
Control group- the group that is exposed to the same conditions as the experimental group except for one independent variable Experimental group- is exposed to the independent (manipulated) variable


16 Scientific Method A scientist would likely set up several sets of control and experimental groups with hopes their observations are reproduced or replicated

17 Scientific Method Two types of data- records of experimental observations or gathered information Qualitative- descriptive; involves characteristics that cannot be easily measured or counted Quantitative- involves numbers like when measuring or counting objects A variety of tools can be used to collect data Most are computer-controlled

18 Scientific Method Care must be taken to avoid error in data collection
Data analysis and sample size should be chosen carefully Instruments for measurement and data collection have limited accuracy A small sample size produces less accurate results than a large sample size

19 Scientific Method Examining the data allows you to draw a conclusion:
Option 1: Data supports the hypothesis never proves it Option 2: Data refutes the hypothesis proves it wrong Option 3: Revise hypothesis and test again


21 When Experiments are Not Possible
Examples: Observing animals Prohibited by ethical considerations Scientists attempt to maintain controlled experiments Study large groups of subjects Identify as many relevant variables as possible

22 1.2 Science in Context Objectives:
Explain how scientific attitudes generate new ideas Describe the importance of peer review Explain what a scientific theory is Explain the relationship between science and society

23 Scientific Methodology
The Process of Science Scientific Methodology Science and Society Communi-cating Results

24 Exploration and Discovery
Scientific Ideas come from Scientific attitudes Practical problems Technology

25 Exploration and Discovery
1. Scientific attitudes help generate new ideas Curiosity Skepticism- question existing ideas and refuse to accept explanation without evidence Open-mindedness- willing to accept other ideas that don’t agree with their hypothesis Creativity

26 Exploration and Discovery
Practical problems E.g. Reducing human impact on the environment

27 Exploration and Discovery
Role of Technology Advances in technology enable scientists to pose new questions and gather data in new ways

28 Scientific Methodology
The Process of Science Scientific Methodology Science and Society Communi-cating Results

29 Communicating Results
Communication and sharing ideas is vital to modern science Peer review- a process where scientific findings are reviewed by anonymous, independent experts Work that is accepted is published in a scientific journal allowing other researchers to access that information and to test and evaluate it Peer-reviewed doesn’t guarantee article is “correct”, but ensures work meets certain criteria

30 Scientific Theories Theory- well-tested explanation that unifies a wide range of observations Happens when a hypothesis is so well supported by the scientific community Or inspired by evidence from related hypotheses Allows scientists to make accurate predictions about new situations

31 Scientific Theories No theory is considered absolute truth
Although some theories are considered the dominant theory because the majority of scientists share that view May be revised or replaced by a more useful explanation

32 Scientific Methodology
The Process of Science Scientific Methodology Science and Society Communi-cating Results

33 Science and Society Science alone cannot answer the questions that affect our society Issues must involve society in which we live, our economy, laws and moral principles We must understand its context in society and its limitations

34 Science and Society Pure science does not include ethical or moral viewpoints Biologists try to explain what life is, how life operates, how it changed over time They cannot answer why life exists or what the meaning of life is Science can tell us how technology can be applied But moral and ethical viewpoints may limit its use

35 Science and Society The way science is applied in society can be affected by bias It is a personal viewpoint, not a scientific one Scientific data can be misinterpreted or misapplied by scientists who want to prove a particular point

36 Science and Society Understanding science can help ensure it is applied in ways that benefit humanity It will help you make complex decisions that involve cultural customs, values, and ethical standards Will help you realize we can predict the consequences of our actions and take and active role in directing our future and that of our planet

37 1-3 Studying Life Objectives:
List the characteristics of living things Identify the central themes of biology Explain how life can be studied at different levels Discuss the importance of a universal system of measurement

38 Characteristics of Living Things
1. Made up of Basic Units called Cells 2. Based on a Universal Genetic Code 3. Obtain and Use Materials and Energy 4. Grow and Develop 5. Reproduce 6. Respond to their Environment 7. Maintain a Stable Internal Environment 8. Change Over Time ALL of these characteristics must be present for something to be considered living

39 Made up of Basic Units called Cells
Organisms are composed of one or more cells Unicellular (one cell) Paramecium caudatum Multicellular (many cells) Ginkgo biloba

40 Based on a Universal Genetic Code
Organisms store the complex information they need to live, grow, and reproduce in a genetic code known as DNA DNA is copied and passed from parent to offspring Life’s genetic code, with a few minor variations, is nearly identical in every organism on Earth

41 Obtain and Use Materials and Energy
Organisms take in materials and energy to grow, develop, and reproduce Chemical reactions used by an organism to build up or break down materials is referred to as metabolism Ex: photosynthesis and cellular respiration

42 Grow and Develop Growth refers to the increase in an organism’s size
Achieved when cells divide Development refers to the changes in that organism that occur over its life As an organism develops, its cells can differentiate to look different and carry out different functions

43 Reproduce Organisms produce new similar offspring
Sexual reproduction- genetic information from two parents unites to produce the first cell of the new organism Used by most plants and animals, protists, fungi, and bacteria Bacteria use a simple type of SR Asexual reproduction- a single organism produces an offspring identical to itself Bacteria, fungi, protists, some plants

44 Respond to their Environment
Organisms detect a stimulus (stimuli plural) which causes a response Stimulus- signal to which organism responds Response- reaction to stimulus

45 Maintain a Stable Internal Environment
Homeostasis is the process by which organisms maintain a relatively stable internal environment even when external conditions change drastically Ex: regulation of body temperature, glucose, water and salts

46 Change Over Time Taken as a group, living things evolve
A shared history is evidenced by the fossil record and similar physiology and biochemistry (proteins and DNA)

47 Characteristic Examples
Living things are made up of units called cells. Many microorganisms consist of only a single cell. Animals and trees are multicellular. Living things reproduce. Maple trees reproduce sexually. A hydra can reproduce asexually by budding. Living things are based on a universal genetic code. Flies, dogs, and maple trees contain similar hereditary information in the form of DNA. Living things grow and develop. Flies begin life as eggs, then become maggots, and then become adult flies. Living things obtain and use materials and energy. Plants obtain their energy from sunlight. Animals obtain their energy from the food they eat. Living things respond to their environment. Leaves and stems of plants grow toward light. Living things maintain a stable internal environment. Despite changes in the temperature of the environment, a robin maintains a constant body temperature. Taken as a group, living things change over time. Plants that live in the desert survive because they have become adapted to the conditions of the desert.

48 Big Ideas in Biology Cellular Basis of Life
Organisms are composed of one or more cells, which are the smallest units that can be considered fully alive. Copyright Pearson Prentice Hall

49 Big Ideas in Biology Information and Heredity
Genetic code is common, with minor variations, to every organism on Earth. That information, carried in DNA, is copied and passed from parents to offspring. Copyright Pearson Prentice Hall

50 Big Ideas in Biology Matter and Energy
Matter serves as nutrients to build body structure and energy to fuel the processes of life. Copyright Pearson Prentice Hall

51 Big Ideas in Biology Growth, Development, and Reproduction
All living things reproduce and the offspring is most often smaller than the mature form. New organisms undergo growth and development where they become larger and generalized cells become specialized to carry out different functions.

52 Big Ideas in Biology Homeostasis
An organism’s ability to maintain a relatively stable internal environment. Copyright Pearson Prentice Hall

53 Big Ideas in Biology Evolution
In biology, evolution, or the change in living things through time, explains inherited similarities as well as the diversity of life. Copyright Pearson Prentice Hall

54 Big Ideas in Biology Structure and Function
Structures evolve in ways that make particular functions possible, allowing organisms to adapt to a wide range of environments. Copyright Pearson Prentice Hall

55 Big Ideas in Biology Unity and Diversity of Life
All living things are fundamentally alike at the molecular level, even though life takes an almost unbelievable variety of forms. Copyright Pearson Prentice Hall

56 Big Ideas in Biology Interdependence in Nature
All forms of life on Earth are connected together into a biosphere, which literally means “living planet.” Copyright Pearson Prentice Hall

57 Big Ideas in Biology Science as a Way of Knowing
Science is not just a list of “facts.” The job of science is to use observations, questions, and experiments to explain the natural world. Copyright Pearson Prentice Hall

58 Big Ideas in Biology Big Idea Book Chapter(s)
Related fields of biology or careers Cellular Basis of Life 1.3, 7, 9 microbiologist Information and heredity 11 Researching genetics Matter and Energy 2, 8, 9 Zoology, physicians Growth, Development and Reproduction 10, 11, 24 Medical, OB/GYN, zoologi Homeostasis 1.3, 7.4, 30.1 medical Evolution 16 and 17 Biogeography, paleontologists Structure and Function 7.2, 17.2, 23… Zoologist, medical Unity and Diversity of Life 11, 16, 18 Genetics, evolution, taxonomy Interdependence in Nature 1.3 and 3 Conservationist, field biologist Science as a Way of Knowing 1, 16, 19, and 6 research

59 SI: A Common Measurement System
What measurement system do most scientists use? Most scientists use the metric system when collecting data and performing experiments.

60 A Common Measurement System
Because the metric system is based on multiples of 10, it is easy to use. Copyright Pearson Prentice Hall


62 Redi’s Experiment, designed to refute Spontaneous Generation- the idea that life could arise from nonliving matter OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. PROCEDURE Uncovered jars Covered jars Controlled Variables: jars, type of meat, location, temperature, time Several days pass Manipulated Variables: gauze covering that keeps flies away from meat Responding Variable: whether maggots appear Maggots appear No maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

63 Repeating Redi Key assumption in science- experimental results can be reproduced because nature acts in a consistent manner Redi’s work followed by Needham-used an experiment with “animalcules” to attack Redi’s work Spallanzani- improved upon Needham’s experiment Pasteur-allowed broth to come into contact with the air

64 Spallanzani’s Experiment
Gravy is boiled. Flask is open. Flask is sealed. Gravy is free of microorganisms. Gravy is boiled.

65 Pasteur’s Experiment Broth is boiled. Broth is free of microorganisms for a year. Curved neck is removed. Broth is teeming with microorganisms. Showed that all living things come from other living things

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