The Science of Biology Chapter 1

Earth Biosphere includes all living things and the places they live. Biosphere includes all living things and the places they live. Biodiversity (variety of organisms) increases from the poles to the equator. Biodiversity (variety of organisms) increases from the poles to the equator. All species are included in an area’s biodiversity. All species are included in an area’s biodiversity. A species is a group of closely related organisms that can successfully reproduce. A species is a group of closely related organisms that can successfully reproduce.

Goal of science Investigate and understand the natural world Investigate and understand the natural world Explain events in the natural world Explain events in the natural world Make predictions Make predictions Biology is the study of living things and their interactions with their environments. Biology is the study of living things and their interactions with their environments.

Ancient Science Asians – herbal medicines Asians – herbal medicines South Americans – developed crop domestication and irrigation South Americans – developed crop domestication and irrigation Egyptians – mummification of royalty Egyptians – mummification of royalty Greeks Greeks Hippocrates – human body is made of humours Hippocrates – human body is made of humours Aristotle – first classification of organisms Aristotle – first classification of organisms

Scientific revolution Science is limited by rules of society and government Science is limited by rules of society and government 15 th century gave rise to study of human and animal bodies; dissection of corpses aided the understanding of the human body 15 th century gave rise to study of human and animal bodies; dissection of corpses aided the understanding of the human body New technologies (microscopes) allowed discovery of cells and microorganisms New technologies (microscopes) allowed discovery of cells and microorganisms

Characteristics of living things Organization – structured; made of cells Organization – structured; made of cells Energy- energy needed for metabolism Energy- energy needed for metabolism Reproduction – produce offspring Reproduction – produce offspring Growth and development – increase number of cells and change Growth and development – increase number of cells and change Respond to stimuli – react to changes Respond to stimuli – react to changes Adaptation – adjust to changes in environment Adaptation – adjust to changes in environment Homeostasis – control internal environment Homeostasis – control internal environment

Homeostasis Controlling internal temperature, blood sugar, acidity, and other conditions Controlling internal temperature, blood sugar, acidity, and other conditions Maintained by negative feedback Maintained by negative feedback

Evolution Change in living things over time Change in living things over time Part of unity and diversity (similarities and differences) of life Part of unity and diversity (similarities and differences) of life Can occur through natural selection of adaptations Can occur through natural selection of adaptations Structures, behaviors, internal processes, and interactions result from evolution Structures, behaviors, internal processes, and interactions result from evolution Does NOT occur during a single life span Does NOT occur during a single life span

Scientific Method Used by scientists to solve problems Used by scientists to solve problems Has 5 major steps Has 5 major steps Observations Observations Define the problem Define the problem Hypothesis Hypothesis Prediction Prediction Experiment Experiment Results Results Conclusions Conclusions

Observations Using your senses to study the world around you Using your senses to study the world around you Can involve tools such as computers, literature, measurement devices Can involve tools such as computers, literature, measurement devices

Define the problem Developed from observations, previous knowledge, and collected data or information Developed from observations, previous knowledge, and collected data or information Data can be qualitative-observations Data can be qualitative-observations Data can be quantitative-measurements Data can be quantitative-measurements

Hypothesis Proposed solution to a problem or question Proposed solution to a problem or question Developed from observations, data, and scientific literature Developed from observations, data, and scientific literature Involves 2 types of reasoning Involves 2 types of reasoning Inductive-specific facts to general rule Inductive-specific facts to general rule Deductive-general information to specific facts (If…then… statements) Deductive-general information to specific facts (If…then… statements)

Predictions Must be testable Must be testable What would happen if the hypothesis is valid? What would happen if the hypothesis is valid?

Experiment A procedure to test the hypothesis under controlled conditions A procedure to test the hypothesis under controlled conditions Constants are conditions that don’t change during the experiment Constants are conditions that don’t change during the experiment Has 2 groups Has 2 groups Control group (used for comparison) Control group (used for comparison) Experimental group (test group) Experimental group (test group) Has 2 variables Has 2 variables Independent variable (condition tested or manipulated) Independent variable (condition tested or manipulated) Dependent variable (what is measured or responds) Dependent variable (what is measured or responds)

Results Gathering data from the experiment Gathering data from the experiment All data must be recorded All data must be recorded Data can be Data can be Quantitative Quantitative Qualitative Qualitative Scientists looking for Scientists looking for Nonsignificant data-data with no effect Nonsignificant data-data with no effect Statistically significant data-large enough effect that data don’t occur by chance Statistically significant data-large enough effect that data don’t occur by chance

Conclusions Analyze your data Analyze your data Was the hypothesis supported? Was the hypothesis supported? Is more data needed? Is more data needed? Data are confirmed after repeated experiments. Data are confirmed after repeated experiments. Supported hypotheses can become theories. Supported hypotheses can become theories.

Theory Proposed explanation for a wide range of observations and results Proposed explanation for a wide range of observations and results Supported by wide range of evidence Supported by wide range of evidence May be broadly accepted but are never proven May be broadly accepted but are never proven Always subject to change Always subject to change

Tools Can be used to make measurements Can be used to make measurements Use the metric (SI) system Use the metric (SI) system Quality of a measurement is described as accuracy and precision Quality of a measurement is described as accuracy and precision Accuracy-how close the measurement is to the true value or quantity Accuracy-how close the measurement is to the true value or quantity Precision-is the exactness of the measurement Precision-is the exactness of the measurement

Metric system (base measurements) Length – meter (m) Length – meter (m) Volume – liter (L) Volume – liter (L) Mass – gram (g) Mass – gram (g) Temperature – Celcius Temperature – Celcius Time – second (s) Time – second (s)

Light Microscopes Use a series of lenses to magnify Use a series of lenses to magnify First used by Anton van Leewenhoek to see microorganisms First used by Anton van Leewenhoek to see microorganisms Visible light is passed through the object to make it visible Visible light is passed through the object to make it visible Can magnigy up to 1500 times Can magnigy up to 1500 times Often use stains to make details stand out Often use stains to make details stand out

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Electron microscopes Beams of electrons used in a vacuum Beams of electrons used in a vacuum instead of visible light instead of visible light Can magnify up to 1,000,000 times Two types SEM-scanning electron microscope passes electrons over surface of object TEM-transmission electron micro. passes electrons through object

Medical imaging X-rays used to view the calcified portions of the body (bones and teeth) X-rays used to view the calcified portions of the body (bones and teeth) Medical resonance imaging (MRI) used to view soft tissues using strong magnetic fields Medical resonance imaging (MRI) used to view soft tissues using strong magnetic fields

Computers and probeware Allow for easy collection of data and fast analysis Allow for easy collection of data and fast analysis Can model systems Can model systems Advanced knowledge in genetics Advanced knowledge in genetics Study DNA molecule (molecular genetics) Study DNA molecule (molecular genetics) Compare genomes of different organisms (genomics) Compare genomes of different organisms (genomics)

Biology and the Future Health Health Healthy food choices Healthy food choices Managing allergies Managing allergies Controlling blood sugar / obesity Controlling blood sugar / obesity Ecology Ecology Reducing pollution Reducing pollution Controlling parasites Controlling parasites Managing water supplies Managing water supplies

Biotechnology Use and application of living things and biological processes Use and application of living things and biological processes Produce medicines Produce medicines Produce larger food crops Produce larger food crops Genetic screening Genetic screening