Biology - Chp 1 - Biology The Study Of Life - PowerPointPresentation Transcript
Do Now1. Get a packet from the desk in the back of the room and write your name on it.2. In your notebooks write the date in the margin and the following Do Now assignment• What is it that you think makes something alive?
Chapter 1Biology: The Study of Life
Section 1.1 What is Biology?
The Science of Biology• People have always been curious about living things• The concepts, principles, and theories that allow people to understand the natural environment form the core of Biology
Biology• The study of Life Bio logy (greek) Life Study of
Biologists study the interactions of life.
Biologists study the diversity of life.• Throughout your study of biology you will come to appreciate the great diversity of life on Earth
Biologists study the interactions of the environment.• No living thing exists in isolation• The study of biology includes the investigation of living interactions• The study of one living thing always involves the study of the others in which it interacts
Ex.)studyingwild ratsmeans youhave tostudy what iteats andwhat eats it
Biologists study problems and propose solutions.• Medical treatment• Disease prevention (humans and other organisms)• Endangered species prevention
Where are all the bees?
Characteristics of Living Things• Biologists have formulated a list of characteristics by which we can recognize living things
Organisms• Anything that possess all the characteristics of life
1. Living things are organized
organization• Orderly structure• All organisms are composed of one or more cells which contain the genetic material or DNA that provides all the information needed to control the organisms life processes
2. Living things make more living things
Reproduction• The production of offspring• Reproduction is not essential for the survival of an organism, but it is essential for the continuation of the organisms species
Species• A group of organisms that can interbreed and produce fertile offspring in nature
3. Living things change during their lives
Growth• An increase in the amount of living material and the formation of new structures
Development• All the changes that take place during the life of an organism
4. Living things adjustto their surroundings
Environment• An organisms surroundingsEx.) air, water, weather, temperature, other organisms in the area
Stimulus• Anything in an organisms external or internal environment that causes the organism to react
Response• A reaction to a stimulus
Homeostasis• Regulation of an organisms internal environment to maintain conditions suitable for survivalEx.) Body temp regulation, water, minerals• Without this ability to adjust to internal changes, organisms die
Energy• The ability to cause change• Organisms get their energy from food
5. Living things adapt and evolve
Adaptation• any structure, behavior, or internal process that enables an organism to respond to environmental factors and live to produce offspring• Anything that makes an organism better at life
How Adaptations Work• Adaptations are inherited from previous generations• There are always some differences in the adaptations of individuals of a population• As the environment changes, some adaptations are more suited Evolution to the new conditions than others• Individuals with more suitable adaptations are more likely to survive and reproduce• As a result, individuals with these adaptations become more numerous
Evolution• The gradual change in a species through adaptations over time• Clues to the way present diversity of life came about may be understood through the study of evolution
In Conclusion• As we learn more about Earth’s organisms in this course, take time to reflect on the general characteristics of life• Rather than simply memorizing facts about organisms or the vocabulary terms, try to see how these facts and terms are related to the characteristics of living things
Do Now• Finish answering questions on page 4. I would like to go over the answers in about 3 minutes.
Section 1.2 The Methods of Biology
Why does rain bring out the worms?
Observing and Hypothesizing• Curiosity is often what motivates biologists to try to answer simple questions about everyday observations• The knowledge obtained when scientists answer questions provides better understanding of general principles or may lead to practical applications or may lead to new questions
The Methods Biologists Use
Scientific Methods• The common steps that scientists use to gather information and answer questions• Scientific methods usually begin with identifying a problem to solve
The Story of the Brown Tree Snake
Hypothesis• An explanation for a question or a problem that can be formally tested• A hypothesis is not a random guess!• The scientist has some idea of what the answer might be through personal observations, extensive research, or previous investigations
Experiment• An investigation that tests a hypothesis by the process of collecting information under controlled conditions
What is a controlled experiment?• Some experiments involve two groups: the control group and the experimental group
Control• The group in which all conditions are kept the same
Experimental Group• The test group in which all conditions are kept the same except for the single condition being tested
Does fertilizer help plants grow taller? Water + Fertilizer Water
Designing an experiment• In a controlled experiment, only one condition is changed at a time
Does fertilizer help plants grow taller? Water + Fertilizer Water Controls •Same volume of water •Same temperature •Same sun exposure
Independent variable• The condition in an experiment being changed
Dependent variable• The condition that results from a change in the independent variable
Does fertilizer help plants grow taller? (centimeters)Growth Fertilizer No Fertilizer
Now You Try…
A number of rats are divided into two groups:One group is fed a normal diet, whereas theother group is fed the same diet but with onenecessary mineral left out. The animalsreceiving the normal diet remained healthy;those in the other group grew weaker.Formulate a hypothesis based on thisexperiment.
A scientist conducted an experiment to determine theeffect of environment on the color of fur of aHimalayan rabbit. The Himalayan rabbit typically has awhite coat except for its colder nose, feet, tail, andears, which are black. The scientist shaved an area ofhair on the back of each rabbit, then placed an icepack over the shaved area on one rabbit (A).
Using Tools• To carry out investigations, scientists need tools that enable them to record information
Maintaining Safety• Safety is another important factor that scientists consider when carrying out investigations
Safety Symbol• A symbol that warns you about a danger that may exist from chemicals, electricity, heat, or procedures you will use
Gathering Data• To answer their questions about scientific problems, scientists seek information from other investigations
Data• Info obtained from investigations or experimental results
Thinking about what happened• After careful review of the results, the scientist must come up with a conclusion• Was the hypothesis supported by the data?• Was it not supported? Is more data needed?• Does the experiment need to be repeated?• After analyzing the data, most scientists have more questions than they had before the investigation
Reporting results• Results and conclusions of investigations are reported in scientific journals
Verifying results• When a hypothesis that is supported by many separate observations and investigations usually over a long period of time, becomes a theory
Theory• An explanation of a natural phenomenon that is supported by a large body of scientific evidence obtained from many different investigations• A theory results from continual verification and refinement of a hypothesis• In addition to theories, scientists also recognize certain facts of nature called laws or principlesEx.) gravity
Do Now• Get your homework out (pg 8) and place it on top of your desk so I can check it.• In your notebook, please describe this class in anyway you’d like.
Do Now200 carrot seeds each were used in aninvestigation to test for the influence oftemperature on germination of seeds.Group A had 150 seeds and was kept ata temperature of 20 degrees Celcius andGroup B had 50 seeds and was kept at 10degrees Celcius. All other conditions werethe same.
Section 1.3 The Nature of Biology
Kinds of Information• Scientific information can usually be classified into one or two main types, qualitative or quantitative
Quantitative information• Numerical data• Numerical values are compared• Quantitative data may be used to make graphs or tables
Measurements in the International System• Scientists use a form of the metric system called the International System of measurements or SIQ: Why is it important that all scientific measurements be done in the same way?A: Not everyone uses the English system of measurements that we use
Advantage of SI• Only a few basic units• Decimal system, measurements can be expressed in multiples of ten or tenths of a basic unit by applying a standard set of prefixes to the unit• In biology, the metric units you will encounter most often are…
Metric Units• meter _______________ (length)• gram _______________ (mass)• liter _______________ (volume)• second _______________ (time)• Celsius _______________ (temperature)
Qualitative information• Observational data• Some phenomena aren’t easily expressed as quantitative information
Science and Society• Some people blame scientists for the existence of controversial things in science• To comprehend the nature of science, people must understand that knowledge gained through scientific research is never inherently good or bad• Society as a whole must take responsibility for the ethical use of scientific discoveries
Ethics• The moral principles and values held by humans
Can science answer all questions?• No, some questions are simply not in the realm of science• Ex.) good vs. evil, ugly vs. beautiful• These questions cannot be tested using scientific methods• However, this does not mean that these questions are unimportant
Technology• The application of scientific research to societies needs and problems
Technology has helped us in many ways • Increase production of food • Decrease the amount of manual labor • Aided in the reduction of wastes and environmental pollution
The advances of technology hasresulted in some serious problems too • Too much fertilizer can contaminate water • Automobiles have led to increased air pollution
In Conclusion• Science and technology will never answer all of the questions we ask, nor will they solve all of our problems• However, during your study of Biology you will have many of your questions answered, and you will explore new concepts• Don’t forget, you are part of this living world and you can use the process of science to ask and answer questions about that world