1. What is Biology in the 21st Century?
Chapter 1

2. What is Biology?
The concepts, principles, and theories that allow people to understand the natural environment form the core of biology
Biology is the scientific study of ALL forms of life
- Bio – means live;
- ology- means the study of

3. The Science of Biology
Life on Earth includes not only the common organisms you notice every day, but also distinctive life forms that have unusual behaviors.
A key aspect of biology is simply learning about the
different types of living things around you

4. Science is the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested.
Biology is one of three basic areas of science:
1. Life Science
2. Earth Science
3. Physical Science

5. Earth is home to a large diversity of life
Biosphere:
Different types of plants, animals, and other living things are found in different areas of the biosphere
The biosphere includes all living things and all the places they are found
Biodiversity
1. Generally increases from the poles to the equator
2. Is greater in areas with consistently warmer temperatures
Biodiversity is greater closer to the equator.

6. The variety of organisms in a given area is called the biological diversity OR Biodiversity

7. Every part of the biosphere is connected with every other part.
The biosphere includes many environments.
1. land environments [desert, grassland, & different types of forest]

8. The biosphere includes many environments
2. saltwater and freshwater environments
3. portions of the atmosphere
Tidepool
Estuary

9. Living things are organized
When biologists search for signs of life, one of the first things they look for is structure. That’s because they know that all living things show an orderly structure, or organization.

10. A species is one particular type of living thing.
Members of a species can interbreed to reproduce.
There are about 2 million different living species have been identified.
Honeypot Ants live in the desert where food and water are scarce. These ants act as a storage tank for other ants in the colony. They gorge themselves with food, hang from the ceiling of their nest, and regurgitate food for the worker ants.

11. Characteristics of living things
Biologists have formulated a list of characteristics by which we can recognize living things
Only when something has all of them can it then be considered living.
Anything that possesses all of the characteristics of life is known as an organism

12. All organisms share certain characteristics
1. All living things are made up of one or more cells. -a cell is the basic unit of life. -An organism with one cell is called a single celled organism -An organism with more than one cell is called a multicellular organism

13. All organisms share certain characteristics
2. All organisms need a source of energy to carry out life processes
Energy is the ability to cause change or do work
All living things use chemical energy
In all organisms, energy is important for metabolism or all the chemical processes that build up or break down materials.

14. All organisms share certain characteristics
3. All organisms must react to their environment to survive -Light temperature and touch are just a few physical factors called stimuli to which an organism must respond.

15. All organisms share certain characteristics
4. All members of a species must have the ability to produce new individuals or reproduce.
Reproduction allows organisms to pass along their genetic material to their offspring
All genetic material
consist of DNA

16. All organisms share certain characteristics
5. All organisms must maintain homeostasis to survive in diverse environments
Homeostasis is the maintenance of constant internal conditions.
Homeostasis is usually maintained through negative feedback.
Negative feedback systems return a condition to its normal (set) point
Polar Bears can maintain homeostasis in very cold climates because their hairs are
hollow and allows the bear to retain its body heat

17. All organisms share certain characteristics
6. Evolution explains the unity and diversity of life
Evolution is the change in living things over time.
The genetic makeup of a population of a species changes.
Evolution can occur through natural selection of adaptations.
Adaptations are beneficial inherited traits that are passed to future generations.
Orchids have flowers that look like insects

18. Evolution accounts for both the diversity and the unity of life.
Evolution is the unifying theme of biology
It accounts for both the diversity and the similarities or unity of life

19. Scientific Thinking and Processes

20. The Scientific Method
The common steps that biologists and other scientists use to gather information and answer questions are collectively known as scientific methods
Curiosity drives scientists to ask questions about the world around them
Skepticism requires critical thinking to find answers to questions
Logical thinking uses reasoning skills to make a conclusion from the research

21. Empirical Evidence
One of the most important points of science is that scientific evidence may support or even overturn long standing ideas
Science depends on Empirical Evidence (observed directly through research & investigations) as the basis for scientific knowledge
These ideas are used to construct testable explanations and predictions of natural phenomena

22. Like all science, biology is a process of inquiry.
Scientists make careful and systematic observations.
Scientists record observations as data.
Scientists form a hypothesis as a possible answer to a question.
Scientists test their hypotheses and analyze their data.

23. Biologists use experiments to test hypotheses.
Observational studies allow scientists to describe a phenomenon.
Observations include
Using our senses to
Study the world
Observations are often recorded as Data
Two general types of Data:
Qualitative Data
Quantitative Data

24. Observations are recorded as data
Qualitative data
Quantitative data
Descriptions of a phenomenon that can include Sight, Sounds, Smells
This type is used to report what happens but not how it happens
Characteristics that can be measured or counted
ie. Mass, volume, temperature, or anything expressed as a number

25. Data Information gathered in an experiment Must be organized
Can be organized into charts, tables, or graphs
Can display time, temperature, length, mass, area or volume

26. Hypothesis: an educated guess
It suggested solution to the problem.
Must be testable
Sometimes written as If…Then… statements
Predicts an outcome
An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.

27. Biologist use experiments to test hypothesis
One example involves the endangered white stork which has decreased drastically since 1950’s
To help protect the stork, Biologists study migration patterns through observations scientists can study migration paths & distance
This told scientists where the storks were breeding and how many eggs they were laying
Because of these efforts, stork populations have rebounded by 20% worldwide

28. Experiment
A procedure to test the hypothesis by collecting information under a controlled conditions.
Scientists test hypothesis repeatedly (3x) 3 times
After experimentation-scientists analyze the statistical data to see whether the hypothesis is supported

29. Are observed and measured during an experiment
In experiments, scientists study factors called Independent variables and dependent variables to find cause-and-effect relationships
Independent Variable
Dependent variable
in an experiment is a condition that is manipulated or changed by a scientists.
The effect of manipulating an independent variable are measured by changes in dependent variables
Are observed and measured during an experiment
They are the experimental data
Changes in dependent variables depend upon the manipulation of the independent variable

30. Example:
Suppose a scientist is testing medications to treat high blood pressure
The independent variable is the dose of medication
The dependent variable is the patients blood pressure

31. Experimental studies allow scientists to determine what causes a phenomenon.
Independent variables are manipulated.
Dependent variables are observed and measured.
Constants are conditions that are kept the same.

32. Example of Controls & Variables
For example, suppose you want to figure out the fastest route to walk home from school.
You will try several different routes and time how long it takes you to get home by each one.
Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

33. What are the Variables in Your Experiment?
Varying the route is the independent variable
The time it takes is the dependent variable
Keeping the same walker throughout makes the walker a control variable.

34. One more thing… it is best to make several trials with each independent variable. A good experiment is tested 3 times!!!!! (for accuracy)

35. Two possible outcomes or results
Nonsignificant
Statistically Significant
Nonsignificant:
The data show no effect or an effect so small that the results could have happened by chance
Statistically Significant:
The data show an effect that is likely not due to chance. When data do not support a hypothesis, the hypothesis is rejected
The data are still useful because they lead to a new hypothesis

36. Conclusion
The answer to the hypothesis based on the data obtained from the experiment

37. A theory explains a wide range of observations.
Theories explain a wide range of observations and experimental results.
A theory is supported by a wide range of scientific evidence.
Theories can change based on new evidence.

38. Ethics Ethics refers to the moral principles and values held by humans
Society as a whole must take responsibility for the ethical use of scientific discoveries

39. https://www.youtube.com/watch?v=iHu6LVg-0Hs Waterslide
Mythbusters…
Waterslide

40. Biologists’ tools and technology

41. Technology plays a major role in the increase of biological knowledge
Can you imagine life without cars, computers or cell phones?
Technology changes how we live & work
Technology today allows biologists to view tiny structures within cells and activity within a human brain, or study genes

42. Tools are used in scientific investigations
Tools serve a variety of purposes:
examples:
laboratory glassware & hot plates are used in various experiments
Microscopes and hand lenses are used to enhance senses
Rulers, balances, and timing devices help gather quantitative data
Computer software analyzes and reports data

43. Quantitative Data: Quantitative Data are gathered through measurements
Measurements determine the dimensions of something using a standard unit
The modern metric system is called the International System of Measurements or SI and is the universal language for all scientific measurements.

44. The quality of measurement can be described by their accuracy: how close a measurement is to the true value and precision: the exactness of measurement
Accuracy and Precision are demonstrated by the results of horseshoe tosses
When the horseshoes are close to each other, the results are precise or when centered around the goal post they are accurate.
When the horseshoes are centered around the goal post & close to each other, the result are both precise and accurate

45. Imaging technologies provide new views of life.
After the late 1600’s and the invention of the microscope, scientists had the ability to study living things that they never knew existed .
The microscope was the first piece of technology to change the study of biology
A microscope provides an enlarged image of an object.
stomata
Types of Microscopes:
Light Microscopes (LM)
magnify specimens up to times their actual size.

46. b. Electron Microscopes
1st developed in the 1930’s
Used to see cells and smaller things
Magnify 1,000,000 times their actual size
Cannot be used to study living organisms because the specimens being studied have to be in a vacuum

47. 2 types of Electron Microscopes
1. Scanning Electron Microscope (SEM)
Uses electrons instead of light for form an image
Allows researchers to examine a much bigger variety of specimens.
Stomata

48. 2 types of Electron Microscopes
2. Transmission Electron Microscope (TEM)
Transmits electrons through a thin slice of a specimen
It makes a two-dimensional image similar to a light microscope but it has a much higher magnification
stoma

49. Medical Imaging X-Ray Images Magnetic Resonance Imaging (MRI)
Formed by x-rays which pass through soft tissues like skin and muscle but are absorbed by bone and teeth
Magnetic Resonance Imaging (MRI)
Uses a strong magnetic field to produce a cross-section image of a part of the body
Images soft tissues

50. Medical Imaging Functional MRI:
Advances in technology have produced this new uses for MRI’s
Functional MRI’s can show which areas of the brain are active while a person is doing a particular task

51. Complex systems are modeled on computers.
Computer models are used to study systems that cannot be studied directly.
heart attacks
Normal heartbeat
effect of medicines on the human body
movement of water molecules into and out of a cell
spread of a disease through a population
Heart attack
Computer models are used when experiments are not safe, ethical, or practical.