CHAPTER 1 BIOLOGY THE SCIENCE OF LIFE
BIOLOGICAL THEMES 1. Cell Structure & Function cell is the basic unit of life all organisms are composed of at least one cell Unicellular single celled ; bacteria, ameba, paramecium Multicellular many celled; animals, plants, fungi
Cell similarities Contain cell membrane & cytoplasm Contain genetic material Made of organic compounds (contain carbon)
BIOLOGICAL THEMES 2. STABILITY & HOMEOSTASIS - Organisms work to maintain homeostasis stable internal conditions - Examples: - Sweating - Fever - Increasing white blood cells
BIOLOGICAL THEMES 3. REPRODUCTION & INHERITANCE - Reproduction producing new organisms - Asexual hereditary information from organisms is not combined - Binary fission splitting in two - Sexual hereditary information from two parts of an organism or two organisms is combined - Fertilization egg & sperm unite - Pollination fertilization in plants - Inheritance passing of hereditary material (DNA) to offspring
BIOLOGICAL THEMES 4. Evolution - Changing of an organism over time - Natural selection suggests that organisms with favorable traits called adaptations have a greater chance at survival
BIOLOGICAL THEMES 5. INTERDEPENDENCE OF ORGANISM - Ecology study of the interactions among organisms and their environment - Symbiosis relationship shared between 2 different organism
- Types of symbiosis - Predation one organism hunts 9 predator) and kills another (prey) - Parasitism one organism (parasite) lives off another (host)
- Mutualism both organisms benefit - Commensalism one organism benefits while the other is unaffected
BIOLOGICAL THEMES 6. Matter, Energy & Organization - Ways in which organism obtain, use & transfer energy - Autotrophs make their own food; include plants, algae & some bacteria - Most commonly done through photosynthesis energy from sun converted to chemical energy
AUTOTROPHS
HETEROTROPHS
- Heterotrophs depend on others for their food - Carnivores eat animals - Herbivores eat plants - Omnivores eat animals & plants - Scavengers eat dead organisms - Decomposers breakdown dead plant & animal matter to simpler molecules
CHARACTERISTICS OF LIFE CELLS all organisms made of at least one cell
CHARACTERISTICS OF LIFE Organization 6 levels Chemical foundation ; atoms, molecules & compounds Cellular basic unit of living things Eukaryotic cell with a nucleus Prokaryotic cell lacking a nucleus Tissue 2 or more cells performing similar functions Organs structures made of 2 or more tissues performing similar function Systems 2 or more organs performing similar functions Organism all levels working together
CHARACTERISTICS OF LIFE Energy use - Metabolism sum of all chemical reactions that occur in an organism
CHARACTERISTICS OF LIFE Homeostasis - Maintaining stable internal conditions
CHARACTERISTICS OF LIFE Growth -nonliving things grow by accumulating more of the material they are made of - Living things grow through cell division & cell enlargement - Development how an adult organism arises
CHARACTERISTICS OF LIFE Reproduction - Producing new offspring - needed for the continuation of a species
SCIENTIFIC METHOD STATE THE PROBLEM OR QUESTION COLLECT DATA - Observation use of senses; qualitative - Measuring measured with numbers; quantitative - Sampling using small parts to represent an entire population - Organizing data place in logical order; graph, chart, table, map, diagram, etc.
SCIENTIFIC METHOD HYPOTHESIZING - Statement that explains the observations & can be tested
SCIENTIFIC METHOD EXPERIMENTING - Controlled experiments compare a control group with an experimental group - Independent variable factor which is different for the control & experimental group - Dependent variable results from the independent variable - Constants factors that are the same for both groups
Scientists want to test the effect of sunlight on the growth of tomato plants. Each plant receives 100ml of water daily and 5 mg of plant food. Plants receive the following amounts of sunlight: Plant A 0 hours Plant B 4 hours Plant C 6 hours Plant D 8 hours
Independent Variable amount of sunlight Dependent Variable growth of the plant Constants tomato plants, water & food Control Group Plant A Experimental Groups Plant B, C, D Hypothesis Sunlight will affect plant growth plants that receive more sunlight will grow taller Plants that receive less sunlight will not grow
SCIENTIFIC METHOD DRAWING CONCLUSIONS - Does data support the hypothesis? - Inference a conclusion based on previous knowledge - Theory statement of what is thought to be true ; can be proven wrong - Scientific Law -
SCIENTIFIC TOOLS & TECHNIQUES A. MICROSCOPES instrument that produces an enlarged image Magnification increase of an objects size Resolution (resolving power) power to show detail and distinguish between two objects
SCIENTIFIC TOOLS & TECHNIQUES Compound Light Microscope uses light & a set of lenses to form an image Eyepiece contains ocular lens; magnifies image 10X Revolving nosepiece contains the objective lenses Objective lens lens directly above specimen Low power 4 or 10X ; shows greatest area High power 40X ; shows less area but more detail Stage holds slide & contains an opening for light to pass through Iris or Diaphragm controls amount of light passing through stage Total Magnification = Ocular X Objective
SCIENTIFIC TOOLS & TECHNIQUES B. Electron Microscopes Use electron beams to form images SEM scanning electron microscope TEM transmission electron microscope
SCIENTIFIC TOOLS & TECHNIQUES C. Chromatography Separation of mixtures into chemical components
D. Electrophoresis carry with electricity Separates fragments such as DNA & proteins By their size