Section 1 the world of biology Section 2 themes in biology Section 3 the study of biology Section 1 the world of biology objectives Relate the relevance of biology to a persons daily life ID: 683929
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Chapter 1 The science of Life
Section 1 – the world of biology
Section 2 – themes in biology
Section 3 – the study of biologySlide2
Section 1 – the world of biology objectives
Relate the relevance of biology to a person’s daily life.
Describe the importance of biology in human society.
List the characteristics of living things.
Summarize the hierarchy of organization within complex multicellular organisms.
Distinguish between homeostasis and metabolism and between growth, development, and reproduction.Slide3
Biology and you
Biology is the study of life
How living things work
How they Interact with the environment
How they change over time
Biologists study many different types of living things.Slide4
Biology and You
Microorganisms – Microbiology
Bacteria – bacteriology
Fungi – mycology
Viruses – virology
Insects – Entomology
Plants - Botany
Birds – Ornithology
Fish – Ichthyology
Amphibians and reptiles – Herpetology
Cancer – Oncology
Cells and Tissues – Histology
Diseases and Human Health – Epidemiology Slide5
Biology and You
Biologists of various types spend their lives trying to better understand the living world.
Biologists work hard to solve problems that society feels are important
Cure for Cancer
Sustainable farming
Cleaning up pollution
Better treatments for diseases
Vaccines and pharmaceuticals
The better you understand the world around you the better you can direct scientists’ research. You will help determine what important topics get funding. (by electing government officials)Slide6
Characteristics of Life
When is something considered alive?
What are the characteristics necessary for life?Slide7
Characteristics of Life
Organization and the presence of one or more cells
Response to stimulus
Homeostasis
Metabolism
Growth and development
Reproduction
Change through timeSlide8
Organization and cells
Organization is the high degree of order within an organism’s internal and external parts.
Also its interactions with the living world
Compare an Owl and a RockSlide9
Organization and cells
All living things are made up of one or more cells
A cell is the smallest unit that can perform all life’s processes
Unicellular – made up of one cell
Multicellular – made up of multiple cells
Who remembers the hierarchy of Cellular Organization?Slide10
Hierarchy of organizationSlide11
Response to Stimuli
Stimulus is a physical or chemical change in the internal or external environment.
Examples:
What happens when you get cold?
What happens when you walk into a dark area after being in the sun?
Organisms must be able to respond and react to changes in their environment in order to stay alive.Slide12
Homeostasis
Homeostasis is the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing.
Maintaining a state of balance
Organisms have systems that help to regulate temperature, water content, and uptake of nutrients by the cells.
Multicellular organisms usually have more than one way to maintain these conditions.
Burning cellular energy for heat or fluffing of feathers or fur to remain warm when the external conditions are cold.Slide13
Metabolisms
Metabolism is the sum of all the chemical reactions that take in and transform energy and material from the environment.
Photosynthesis
Eating foodSlide14
Growth and Development
All living things grow and increase in size.
Crystals or icicles grow by accumulating more of the same material
Growth of living things results from the division and enlargement of cells
Cell division is the formation of two new cells from an existing cell
Unicellular organisms typically grow after division
Multicellular organisms mature through cell division, cell enlargement, and developmentSlide15
Growth and Development
Development is the process by which an organism becomes a mature adult.
Involves cell division and cell differentiation, or specialization
Adults organisms are composed of many cells specialized for different functionsSlide16
Reproduction
Reproduction is the process by which organisms produce new organisms like themselves.
Reproduction is not essential for the survival of an individual organism.
However, it is necessary for the survival of a species as a whole
During reproduction, organisms transmit hereditary information to their offspring.
This information is encoded on DNA.
DNA carries genes Slide17
Reproduction
Sexual Reproduction – hereditary information recombines from two organisms of the same species.
Resulting in offspring that are similar but not identical to their parents.
Plants and animals
Asexual Reproduction – hereditary information from different organisms is not combined
Resulting in the offspring being genetically identical to the parent
Bacteria – binary fission
Hydras and sponges – Budding
Planarians- FragmentationSlide18
Asexual ReproductionSlide19
Change Through Time
The ability of a population of organisms to change over time is important to for the survival in a changing world
The ability to Evolve – Change physically and Genetically over time Slide20
Section 2 – Themes in biology objectives
Identify three important themes that help explain the living world.
Explain how life can be diverse, yet unified.
Describe how living organisms are interdependent.
Summarize why evolution is an important these in biology.Slide21
Diversity and Unity of Life
Diversity, or variety, of life is amazing.
Scientists have identified 1.5 million species on earth. Slide22
Unity in the Diversity of Life
Even with the vast diversity living things are characterized by unity
Genetic code
Presence of organelles that carry out all cellular functions
Share certain genes, but not all.
The “tree of life” shows how organisms are similar and differentSlide23Slide24
Three Domains of Life
Three Main Branches, or domains, on the “Tree”
Bacteria
Archaea
Eukarya
Under these three domains are 6 kingdoms
Bacteria
Bacteria or Eubacteria
Archaea
Archaea
Eukarya
Animalia
Fungi
Plantae
ProtistaSlide25
Interdependence of Organisms
Organisms interact with each other and their environment.
Ecology studies organisms and how they interact with each other and their environment.
It can be very complicated and understanding every detail of these interactions is difficultSlide26
Evolution and Life
Individual organisms change during their lifetime, but their basic genetic characteristics do not change.
However, population of living organisms do change through time, or evolve.
Evolution, or descent with modification, is the process by which the inherited characteristics within populations change over generations, sometimes giving rise to new species.
Evolution helps us to understand how the various branches of the “tree of Life” came into existence and have changed over time.Slide27
Natural Selection
Natural selection is one of the mechanisms of evolution.
Survival of the fittest.
Those organisms with the best traits will survive, breed, and pass those traits on to the next generation.
We will spend more time on evolution and natural selection in later chapters.Slide28
Section 3 – The study of biology objectives
Outline the main steps in the scientific method.
Summarize how observations are used to form hypotheses.
List the elements of a controlled experiment.
Describe how scientist use data to draw conclusions.
Compare a scientific hypothesis and a scientific theory.
State how communication in science helps prevent dishonesty and bias.Slide29
Science as a process
The scientific method is an organized approach to solve or answer scientific questions.
Helps us to learn how the natural world works.
Who remembers the steps of the scientific Method?Slide30
Steps in the Scientific Method
Observation – observe something that causes you to question.
Hypothesis – educated guess
Prediction – what may happen
Experiment – step wise instructions
Analysis – analyze your data
Conclusion – summarize and restateSlide31
Observation
In order to use the scientific method you must observe something that is testable.
Owls can catch prey in total darkness. How?Slide32
Forming a Hypothesis
Before you can form your hypothesis you must do some research.
What has been done on this topic.
This helps you to develop your hypothesis
Should be in an “If...Then” statement and can contain a prediction about what may occur.
If Owls use hearing to catch prey at night, then in a lighted room, the owl will pounce closer to the mouse’s head. But, in a dark room, the owl will pounce closer to a rustling leaf attached to the mouse. Slide33
Designing an Experiment
The experiment must be well organized and contain all necessary information for the experiment to be repeated.
It must also contain an experimental and a control group
The experimental group is the group you are testing your hypothesis on.
The control group is the normal standard against which the biologist can compare results.
The experimental group has the independent variable, the variable that is manipulated by the experimenter.
Presence or absence of light.
The dependent variable is the outcome or response.
Where the owl strikesSlide34
Blind Study
Is a study that is done where the identity of the control and the experimental group is
kept
hidden.
This helps to eliminate bias.
Double Blind
Drug trialsSlide35
Collecting and Analyzing Data
Data should be kept neat and organized.
Charts and graphs should be used to convey the informationSlide36
Drawing Conclusions
Hypotheses are supported or not supported,
they are not Proven.
The conclusion should summarize the experiment and its main points.
It will state areas of possible error, or future studies.Slide37
Hypothesis vs Theory
A hypothesis may be supported, but it does not mean that it is true. A hypothesis should be repeatable. Scientists should get the same or similar results to further support the hypothesis.
When a hypothesis has been supported by many experiments it can become a theory.
Theories are not written in stone.
As new research and tools become available theories can be modified. Slide38
Communication of Ideas
It is important that scientists share their results. It helps to verify their work and leads to new areas of research.
We would not have the scientific advances we have today if scientists did not share their results.
Scientists will publish their results in Peer reviewed journals. (primary Journals)
These are journals that other scientists in their field will read their research to ensure it is done in a scientifically sound manner. Slide39
Honesty and bias
Honesty is essential in science. Falsifying results could mean death for an individual.
Repeating another’s experiment helps to prevent this.
Conflicts of interest are important to avoid.
A scientist who owns a biotech company may not be the best to perform the experiments to Ensure its safety.