Transcript Chapter 1
The Science of Life Biology Organization Cell Unicellular Multicellular Organ Tissue Organelle A. Made of one cell B. The smallest unit that can perform all life’s processes C. Made of many cells D. The study of life E. The high degree of order within an organism’s internal and external parts and in its interactions with the living world. F. Tiny structures inside living cells G. A group of similar cells working together H. A group of tissues that work together to perform a specific job in a living thing. Biological molecule Homeostasis Metabolism Cell Division Development Reproduction Gene I. The sum of all chemical reactions in a living thing that take in and transform energy and materials from the environment J. Formation of two new cells K. Chemical compounds made up of atoms L. A short segment of DNA that had coded instructions for a single trait in an organism M. To produce new organisms similar to oneself N. Process by which an organism becomes a mature adult O. To maintain stable internal conditions Biology Organization Cell Unicellular Multicellular Organ Tissue Organelle D E B A C H G F Biological Molecule Homeostasis Metabolism Cell Division Development Reproduction Gene K O I J N M L Biology is the study of life ◦ From the Latin: Bios = life and ology = study of 1. Cellular Organization ◦ Organization is the high degree of order within an organism’s internal and external parts and in its interactions with the living world. ◦ All living things are made of one or more cells and these cells are highly organized. Unicellular = made of one cell Multicellular = made of many cells Atoms are the smallest particle of an element. They combine to form: Biological molecules which are chemical compounds that join to form: Organelles —Each of these tiny structures within a cell has a special job to do to keep the cell alive The cell is the smallest unit of life A group of cells working together make up a tissue A group of tissues make up an organ Organs combine to form organ systems An organism is a complete and whole living thing 2. Response to stimuli ◦ A stimulus is a sudden change in an organism’s environment ◦ All organisms must be able to respond or react to these sudden changes 3. Homeostasis is the maintenance of a stable level of internal conditions even though environmental conditions are constantly changing. 4. Metabolism is the sum of all the chemical reactions that take in and transform energy and materials from the environment. ◦ Different organisms have different metabolic rates Describes as a fast or slow metabolism 5. Growth and Development ◦ All living things grow or increase in size ◦ Growth results from the division and enlargement of cells ◦ Cell division is the formation of two new cells from an existing cell. ◦ Development is the process by which an organism becomes a mature adult. ◦ A multicellular organism is composed of trillions of specialized cells, all which developed from a single cell, the fertilized egg. 6. Reproduction ◦ All organisms produce new organisms like themselves. This is essential for the survival of the species. Hereditary information is passed from parent to offspring on the coded information molecule known as deoxyribonucleic acid or DNA. ◦ A gene is a short segment of DNA that contains the instructions for a single trait of an organism. 7. Change Through Time ◦ All populations of living things evolve or change through time. This is important for species survival in a changing world. ◦ This also helps to explain the diversity of lifeforms on Earth. Domain Kingdom Ecology Ecosystem Evolution Natural Selection Adaptation A. Communities of living species and their environments B. Branch of biology that studies how organisms interact with the environment C. Largest division in the classification of living things D. Traits that improve an individual’s ability to survive E. Theory stating that organisms with favorable traits are more likely to survive and pass on those traits F. Second largest division in the classification of living things G. Descent with modification Domain Kingdom Ecology Ecosystem Evolution Natural Selection Adaptation C F B A G E D Three important themes help explain the living world and are part of biology ◦ Diversity and Unity of Life ◦ Interdependence of Organisms ◦ Evolution of Life 1. Diversity and Unity of Life ◦ These terms seem to contradict each other Diversity = variety. Over 1.5 million species of living things exist on Earth. They are extremely different from each other. Unity = similar. There are certain genetic similarities common to all living things, no matter how different they appear to be. All living things have a genetic code found in the DNA molecule. They share certain genes, yet no two types of organisms have the same full set of genes. A tree of life places organisms with more similarities in their genes on closer branches. All life is connected, yet there are different lineages representing different species. The three branches represent the three Domains in the living world: Archaea, Bacteria, and Eukarya Most scientists also recognize six kingdoms: ◦ ◦ ◦ ◦ ◦ ◦ Archaeabacteria Eubacteria Protista Fungi Plantae Animalia 2. Interdependence of Organisms ◦ Organisms interact with each other. Nothing can survive completely independent of another living thing. Ecology =the branch of biology that studies how organisms interact with each other and their environment. Ecosystem = communities of living species and their physical environments. 3. Evolution of Life ◦ Populations of living organisms change through time or “evolve” Evolution =descent with modification. It is the process by which the inherited characteristics of a species change over time. Natural Selection = theory that states organisms with traits best suited to their environment will most likely survive and pass on those favorable traits. It explains how species evolve and new species emerge. Adaptation = traits that improve an individual’s ability to survive. Genetic variety allows some organisms to be born with favorable adaptations. Scientific Method Observation Hypothesis Prediction Experiment Control group Experimental group Independent variable Dependent variable Theory Peer review A. Forecasts what would happen in a test B. Used to test a hypothesis C. Organized set of steps used to solve a problem D. Provides a standard for comparison E. The act of perceiving something F. A proposed explanation G. A highly tested and generally accepted principle that explains an observation H. Experts critique each others work I. A.k.a. manipulated variable J. A.k.a responding variable K. Group in which one factor is different Scientific method Observation Hypothesis Prediction Experiment Control group Experimental group Independent variable Dependent variable Theory Peer review C E F A B D K I J G H The scientific method is an organized set of steps used to solve problems: ◦ Make an Observation —perceive a natural occurrence which causes you to pose a question ◦ State the Question ◦ Hypothesize and Predict—give an explanation that tries to answer the question and then make predictions as to what would happen if the hypothesis were true. ◦ Experiment—design and run a test for the hypothesis ◦ Analyze Data and Draw Conclusions ◦ Publish Conclusions—so that others can verify, reject, or modify your results. A good experiment is called a controlled experiment. It has several parts: ◦ Control group —this group provides a normal standard against which results are compared ◦ Experimental group —this group is identical to the control group except for one factor ◦ Independent variable —the factor that changes in an experiment. Also called the manipulated variable. ◦ Dependent variable —the factor that is being observed or measured. Also called the responding variable. Scientists collect two types of data: ◦ Quantitative Data —data measured in numbers ◦ Qualitative Data —data recorded as a description of something ◦ Both must be detailed A scientific theory is a highly tested, generally accepted principle that explains a vast number of observations and experimental data. Examples: Cell Theory, Quantum Theory, Theory of Relativity, Theory of Natural Selection A typical research paper has four sections: ◦ Introduction —states the problem and hypothesis to be tested ◦ Materials and Methods — describes the experiment ◦ Results —states the findings ◦ Discussion —gives the significance of the experiment and future directions the scientist will take. The microscope will be used quite often throughout this course. Proper use will be covered in a lab activity. The metric system will be used to take measurements in several lab activities. The metric system will be reviewed during that time.