Biology • The Science of LIFE • Bio means life • Logos means study • • • •
1- Study the origins and history of life. 2- The structures of living things 3- How living things interact with one another. 4- How living things function.
Biology • The study of life. • What is life ? • You know it when you see it. • But can you define it? • Life is : • The on going process of which living things are a part. • The period between birth and death of an organism. • The state of something that has been born and has yet to die. •
***Life is a multi-faceted concept with NO simple definition.
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Life • A series of Chemical reactions. • When the reactions occur you are alive. • When they no longer occur you are dead.
What is life?
Characteristics of Living things.
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1- Made of cells (cellular) • Unicellular • • • •
Multi-cellular
2- Reproduce • Asexual • Sexual
3- Based on a genetic code • •
(D.N.A) Inherited traits
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4- Grow and develop
5- Obtain and use Energy •
Autotroph
•
Heterotroph
6- Respond to Stimuli • Reacts to internal and • External stimuli.
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7- Maintain an internal balance Homeostasis
8- Change over time Evolution
Have you ever taken a look at the Natural World, and wonder why things happen?
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This is SCIENCE!!!!!!! • Science is a body of knowledge based on the study of the natural world.
Why is the sky Blue?
Why do days get longer in the summer and shorter in the fall?
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Why do leaves change colors in the fall?
Why do the leaves only change certain colors?
How do geese know to fly South in the Winter and North in the Spring?
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How do they find their way?
How do whales migrate, thousands of miles each year?
How do salmon find their place of birth, in order to spawn ?
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How do swallows return to San Juan Capistrano on the same day every year?
We All observe and form questions about the natural world!
So how do we answer these questions about the natural world!
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Science • Process of THINKING and LEARNING about the Natural World. •
Observation
•
Curiosity
• •
Questions SCIENCE
Methods of Science • Observation – direct method of gathering information.
• Inferences – combining what you know with what you have learned. • *** Using observation and knowledge to determine a conclusion.
Scientific Method • 1- Observation – Develop a problem or question
• 2- Form a Hypothesis – Prediction, possible answer, explanation
• 3-Test the Hypothesis – Observation, experiment – Collect data
• 4- Conclusion – Analyze the data
• 5- Theory – Well tested explanation, or answer
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Experimental design • Independent variable - is the variable that is varied or manipulated by the researcher. • Dependent variable - is the response that is measured. • ****what you are doing is the independent, what you are trying to figure out is the dependent."
• (Independent variable) causes a change in (Dependent Variable) and it isn't possible that (Dependent Variable) could cause a change in (Independent Variable). • For example: • (Time Spent Studying) causes a change in (Test Score) and it isn't possible that (Test Score) could cause a change in (Time Spent Studying). • We see that "Time Spent Studying" must be the independent variable and "Test Score" must be the dependent variable because the sentence doesn't make sense the other way around.
Data collecting • Quantitative – collected as numbers. Numerical data can be measured – time, temperature, length, mass, area, volume or density. Qualitative – description of what our senses detect. Sight, taste, hearing, touch and smell.
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Remember !!! • No Theory is considered absolute truth. • *** As new evidence is uncovered, a Theory may be revised or replaced by a more useful explanation.
Branches of Biology • • • • • • • • • • • • • • •
Based on the type of organism being studied. Zoology - study of animals. Invertebrate Vertebrate Botany - study of plants. Vascular Non-vascular Paleontology - study of ancient life Entomology - study of insects. Morphology - study of external structures of plants, animals Ornithology - study of birds. Cytology - study of cells Genetics – study of genes & heredity Mycology – study of fungi
Study of Biology •
Levels of Organization: (smallest - largest)
• Molecules - group of atoms. • Cells - smallest unit of life • Group of cells - tissues, organs, systems. • Organism - individual living things. • Population - group of organisms, that live in same area. • Community - populations that live together. • Ecosystem - community, non-living surroundings • Biosphere - part of earth that contains all ecosystems.
