Chapter 1-Introducing Biology Review January 2nd
What is Biology? • Biology – the scientific study of all forms of life, or all types of organisms. • What are some characteristics of living things?
7. Living things maintain a stable internal environment (homeostasis).
What is living and nonliving? • Rock? • Leaves? • Yogurt? • Yeast? • Pond Water? • Dirt?
Area on earth with most diversity • Biodiversity increases from Earth’s poles to the equator. • Greater biodiversity is found in warmer areas. • Why? B/c more living things are able to survive in consistently warm temperatures versus areas with large temperature changes.
What are the unifying themes of biology? • Systems exist on all scales of biology Ex. From microscopic molecules to biosphere • Structure is directly related to function Ex. red blood cells, cells of the nervous system 3. Organisms must maintain homeostasis 4. The evolution of organisms explains both the unity and diversity of life.
Structure and Function Related • What something does in an organism is directly related to its shape or form. • Ex: Teeth, Cell types, Feet types
How do organisms maintain homeostasis? • What is homeostasis? • Maintenance of constant internal conditions in an organism • Temp, blood sugar, acidity, etc. • Maintained through negative feedback • Where a change in system helps it return to original state. • Ex: Cruise control, shiver, • Behavior is also maintained by homeostasis
Evolution and Adaptation related • One way evolution occurs is through natural selection of adaptations • Adaptation- an inherited trait that gives an advantage to individual organisms and is passed on to future generations. • Adaptation is fit to the environments • Takes many generations, due to environmental pressures.
Scientific Inquiry • Begins with careful and systematic observations • Biology is a process of inquiry that uses critical and logical thinking to find answers to questions. • Scientific inquiry also requires evidence- just like in a court of law.
Control Group vs. Experimental Group • Control group- one that has not been manipulated. A group separated from the rest of the experiment where the independent variable being tested cannot influence the results. • An experimental group is the group in a scientific experiment where the experimental procedure is performed.
Dependent vs Independent Variable • Independent variable- a condition that is manipulated or changed by a scientist. • Dependent variable- observed and measured during an experiment • The independent variable in an experiment is the variable that YOU change in order to affect the dependent variable. The dependent variable is what is being measured, or what is being affected. • For example: If you are testing how the amount of time you leave a sponge in a bowl of water affects the amount of water absorbed, then the amount of time you leave the sponge in is the independent variable, and the amount of water absorbed is the dependent variable. An easy way to remember it is that the dependent variable all DEPENDS on the independent variable.
Thinking Like a Scientist • Data– Info gathered from observations • Quantitative Data – number data • Qualitative Data – descriptive data • Inference – logical interpretation based on prior knowledge or experience.
Hypothesis and Theory • Hypothesis- proposed answer for a scientific question. • Must be specific and testable • Repeated testing • Two outcomes: nonsignificant and statistically significant • Theory- a proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence. • Natural Selection • By definition they are not proved
Scientific Models • Models are useful tools for scientists as they try to make sense of the world around us. • Models help us to understand complicated things in the world and they have been very valuable in the tremendous scientific and technological advances that we have seen, including those in medicine, genetics, electronics and engineering. • Examples: vaccination, CD, car or bus
Imaging Technologies • Technology plays a major role in increase in knowledge of biology. • Microscope- allows an enlarged image of an object • Cells • Today we have light microscopes, electron miscroscopes (SEM and TEM)
Computer Models • Computer models simulate the interactions among different variables to provide scientists with a general idea of how a biological system may work.
Genomics and molecular genetics • Our understanding of DNA has increased dramatically. • Molecular geneticsis the study and manipulation of DNA on a molecular level. • GMOs, transgenics • Genomics- the study and comparison of genomes both within and across species. • Computer databases of the entire genome
Biotechnology • Biotechnology is the use and application of living things and biological processes • DNA testing in medicine and forensics • transgenic (genetically modified) crops • transgenic bacteria • Concerns: • safety of genetically modified crops • spread of undesirable genes • decrease in biodiversity • ethical considerations • Human Genetic Screening