Chapter 1 Scientific Study of Life Copyright McGraw-Hill Education. All rights reserved. 2012 No reproduction Pearson or Education, distribution without Inc. the prior written consent of McGraw-Hill Education.
Biology, Science, and Society
Figure 1.CI2 Mandatory childhood vaccines? Whooping cough Polio Measles MMR & Autism? Wakefield falsified 1998 study 2010 - Lancet retracts study Are you for or against mandatory childhood vaccines? If you had children, will you vaccinate them?
Figure 1.1 Photo taken from the Hubble Space Telescope showing a tiny portion of the universe. Studies by astronomers have shown that all matter on Earth originated inside stars or with the Big Bang. What is Science? Studying unusual species such as this deep sea glass squid allows biologists to understand the processes by which a species successfully survives. Many different environments exist in the world, but the same physical and chemical laws govern them all. The natural world comprises all matter and energy. An erupting volcano spewing liquid rock and heat is the result of energy that still remains from the creation of Earth nearly 4.6 billion years ago. Jane Goodall has dedicated her life to studying the needs and behaviors of chimpanzees. The DNA of humans and chimps is almost the same, yet important physical and behavioral differences are obvious. Evolution examines how these differences arose.
What is Biology?
Branches of Biology
Human Biology
What is Life?
7 Attributes of Life 1. Order
Figure 1.7-1 Order Atom
Figure 1.7-2 Order Atom Molecule 4 classes of biological molecules Carbohydrates (sugars) Proteins Nucleic acids Lipids
Figure 1.7-3 Order Atom Molecule Cell Cellular Basis of Life Basic unit of life Come from other cells Composed of one or more cells Transforms energy Contains genes (DNA) Enclosed by a membrane
Figure 1.7-4 Order Atom Molecule Tissue Cell Cellular Basis of Life Basic unit of life Come from other cells Composed of one or more cells Transforms energy Contains genes (DNA) Enclosed by a membrane
Figure 1.7-5 Order Atom Organ Tissue Cell Molecule
ORDER Figure 1.3 Cells Endothelial cell Tissues Sheet of Endothelial cells Organ Capillary Emergent Properties Red blood cell Endothelial cell
Figure 1.7-6 Order Organ system Atom Organ Tissue Cell Molecule
Figure 1.7-7 Order Organ system Organism Atom Organ Tissue Cell Molecule
Figure 1.15 ORDER Too small to see with the unaided eye Visible with the unaided eye Multicellular organism Organ system Multicellular organism Organ systems Organs Organ Tissues Cells Tissue Organelles Molecules Cell Atoms Organelle Molecule Atom
Order Organ system Organism Population Organ Tissue Atom Cell Molecule Biological Order above the organism
Order Organ system Organism Population Organ Tissue Atom Cell Molecule Community Biological Order above the organism
Figure 1.7-10 Order Organ system Organism Population Organ Atom Molecule Biological Order above the organism Tissue Cell Community Ecosystem
Order Organ system Organism Population Organ Atom Molecule Biological Order above the organism Tissue Cell Community Ecosystem Biosphere
Figure 1.2 MOLECULE A group of joined atoms. Example: DNA ATOM The smallest chemical unit of a type of pure substance (element). Example: Carbon atom ORGANELLE A membrane-bounded structure that has a specific function within a cell. Example: Chloroplast ORGANISM A single living individual. Example: One acacia tree CELL The fundamental unit of life. Multicellular organisms consist of many cells; unicellular organisms consist of one cell. Example: Leaf cell TISSUE A collection of specialized cells that function in a coordinated fashion. (Multicellular life only.) Example: Epidermis of leaf ORGAN A structure consisting of tissues organized to interact and carry out specific functions. (Multicellular life only.) Example: Leaf POPULATION A group of the same species of organism living in the same place and time. Example: Multiple acacia trees ORGAN SYSTEM Organs connected physically or chemically that function together. (Multicellular life only.) Example: Aboveground part of a plant COMMUNITY All populations that occupy the same region. Example: All populations in a savanna ECOSYSTEM The living and nonliving components of an area. Example: The savanna BIOSPHERE The global ecosystem; the parts of the planet and its atmosphere where life is possible.
Life s Hierarchy of Organization
7 Attributes of Life 1. Order 2. Reproduction
Heritable Information continuity of life From pre-existing cells Sperm cell Nuclei containing DNA Asexual reproduction or Mitosis Egg cell Sexual Reproduction or Meiosis Fertilized egg with DNA from both parents Embryo s cells with copies of inherited DNA Offspring with traits inherited from both parents
Figure 1.6 a. b. Asexual Reproduction Sexual Reproduction
DNA Nucleus Cell Cellular reproduction DNA DNA (copying) Mitosis (clones) Meiosis (variation) Protein Synthesis DNA RNA Protein Nucleotide A C T A T A C C G T A G T A (a) DNA double helix (b) Single strand of DNA
Universal Genetic Code
Universal Genetic Code Examples Naturally produced Gene inserted to produce
7 Attributes of Life 1. Order 2. Reproduction 3. Growth & Development
7 Attributes of Life 1. Order 2. Reproduction 3. Growth & Development 4. Energy Processing & Utilization
Energy Transfer and Transformation Potential & kinetic energy Producers & consumers Sunlight Producers absorb light energy and transform it into chemical energy. Heat When energy is used to do work, some energy is converted to thermal energy, which is lost as heat. Chemical energy Chemical energy in food is transferred from plants to consumers. An animal s muscle cells convert chemical energy from food to kinetic energy, the energy of motion. A plant s cells use chemical energy to do work such as growing new leaves. (a) Energy flow from sunlight to producers to consumers (b) Using energy to do work
7 Attributes of Life Catabolism 1. Order 2. Reproduction 3. Growth & Development 4. Energy Processing & Utilization Metabolism Catabolism breakdown/releases NRG Anabolism builds up/requires NRG Anabolism
7 Attributes of Life 1. Order 2. Reproduction 3. Growth & Development 4. Energy Processing & Utilization 5. Respond to Environment Stimuli
7 Attributes of Life 1. Order 2. Reproduction 3. Growth & Development 4. Energy Processing & Utilization 5. Respond to Environment Stimuli 6. Regulation (Homeostasis)
Regulation Negative Feedback Positive Feedback More, more, more
Positive Feedback 1. Action potentials nerve communication (Na + ) 2. Blood clotting & platelets 3. Birth 4. Breast feeding
Figure 1.5 a. b.
Negative Feedback
7 Attributes of Life 1. Order 2. Reproduction 3. Growth & Development 4. Energy Processing & Utilization 5. Respond to Environmental Stimuli 6. Regulation 7. Evolutionary Adaptations
Cellular Basis of Life 1. Basic unit of Life 2. Composed of one or more cells 3. Arises from pre-existing cells Asexual (Mitosis)/Sexual (Meiosis) 4. Transform energy 5. Information retention (genes) 6. Surrounded by a membrane Cell Theory
Figure 1.2 Cellular Basis of Life a) Several Staphylococcus aureus, the bacterium that causes food poisoning (SEM X 50,000). Prokaryote (1 10 um) b) Some of the many cells that line the inner surface of the human stomach (SEM X 500). Eukaryote (10 100 um) Membrane bound organelles
Cellular Basis of Life Figure 1.8 Eukaryotic cell Membrane Cytoplasm Prokaryotic cell DNA (no nucleus) Membrane Nucleus (membraneenclosed) Membraneenclosed organelles DNA (throughout nucleus) 1 m
Methilcillin resistant Staphylococcus auerus (MRSA)
Interaction with the Environment (Biotic & Abiotic Factors) Leaves absorb light energy from the sun. Sunlight CO 2 Leaves take in carbon dioxide from the air and release oxygen. O 2 Cycling of chemical nutrients Leaves fall to the ground and are decomposed by organisms that return minerals to the soil. Water and minerals in the soil are taken up by the tree through its roots. Animals eat leaves and fruit from the tree.
Unity in diversity Fungi (decomposers) Plants (photosynthesis) Animals (ingestion) EUKARYA Plants Where do we fit into the natural world? Animals Protists (eukaryotic, mostly unicellular) Fungi Protists Monerans (prokaryotic, unicellular) ARCHAEA Archaebacteria Taxonomy Whitiker s classification BACTERIA Unknown ancestor a) Five-kingdom system. b) Three-domain system.
Phylogenetic Tree of Life based on ribosomal RNA From: Woese et al, 1990
Domains of Life Figure 1.9 DOMAIN BACTERIA Cells lack nuclei (prokaryotic) Most are unicellular DOMAIN ARCHAEA Cells lack nuclei (prokaryotic) Most are unicellular DOMAIN EUKARYA Cells contain nuclei (eukaryotic) Unicellular or multicellular Protista (multiple kingdoms) Kingdom Animalia Unicellular or multicellular Autotrophs or heterotrophs Multicellular Heterotrophs (by ingestion) TEM (false color) 1 μm SEM (false color) 1 μm Prokaryotes DOMAIN EUKARYA LM 200 μm DOMAIN BACTERIA DOMAIN ARCHAEA Animals Fungi Plants Kingdom Fungi Most are multicellular Heterotrophs (by external digestion) Kingdom Plantae Multicellular Autotrophs Protista Common ancestor of all life
Evolutionary adaptation What s an acceptable definition of evolution? What s changing through time?
Charles Darwin Descent with modification Natural selection
Descent with modification
Natural Selection Population of organisms Hereditary variations Overproduction of offspring and competition Environmental factors Differences in reproductive success of individuals Evolution of adaptations in the population
Figure 1.20 Natural selection 1 Population with 2 Elimination of 3 Reproduction of 4 varied inherited individuals with survivors traits certain traits Increasing frequency of traits that enhance survival and reproductive success
Natural Selection Figure 1.8 Generation 1 Generation 2 Multiple generations later Antibiotic present Hair Bacterial cell Time Reproduction and Selection Antibiotic absent Staphylococcus aureus before mutation Mutation occurs (red) SEM (false color) a. b. 10 μm
Figure 1.10 Scientific Method Publish Peer review Make observations Draw conclusions Ask a question Consult prior knowledge Consult prior knowledge Collect and interpret data Formulate a hypothesis Make predictions
Figure 1.8 Scientific Method 4 Experiment or observe 4 Experiment or observe 1 Observe and generalize 2 5 5 Modify hypothesis as necessary and repeat steps 3 and 4 Formulate a hypothesis Modify hypothesis as necessary and repeat steps 3 and 4 Direction of Increasing confidence in hypothesis 3 Make a testable prediction 3 Make a testable prediction 3 Make a testable prediction
Scientific Method Figure 1.11 Observations Questions a. b.
Scientific Method Observations Questions Hypothesis Educated guest why? Background research Tentative explanation Null hypothesis = no difference Alternative hypothesis
Scientific Method Observations Questions Hypothesis Educated guest why? Background research Tentative explanation Predictions For experimental design
Scientific Method Observations Questions Hypothesis Predictions For experimental design Experimentation Qualitative Quantitative Control grp Experimental grp Sample size
Figure 1.9-5 Select a large number of appropriate subjects. Randomly divide the subjects into two groups. Group 1 Group 2 Treat the groups equally in all ways but one. Experimental group: receives treatment Control group: receives placebo Observe or make measurements. Are blood pressures lower in the experimental group? Compare results. Yes No Hypothesis received support. Modify hypothesis to fit the new findings.
Scientific Method Observations Questions Hypothesis Predictions For experimental design Experimentation Analysis - statistics
Freshman enrollment Freshman enrollment Freshman enrollment Types of graphs 4000 4000 4000 3000 3000 3000 Standard error bar 2000 2000 2000 1000 1000 1000 0 0 0 0 10,000 20,000 30,000 0 10,000 20,000 30,000 0 10,000 10,000 20,000 20,000 30,000 Total student enrollment Total student enrollment Total student enrollment a) A scatter plot b) A line graph c) A bar graph
Incidence of illness (# cases/100 child-years) Figure 1.12 30 25 25.86 Any rotavirus illness Severe rotavirus illness 20 15 14.46 10 5 0 Placebo (control) 6.19 6.86 2.15 2.15 0 0 Low Medium High
% with tumors % with tumors Figure 1.A 30 25 Male rats 27 30 25 Female rats Saccharin-fed Controls 20 19 20 15 15 10 10 5 0 5 4 3 0 0 0 0 0 Parents Offspring Parents Offspring
Scientific Method Observations Questions Hypothesis Predictions For experimental design Experimentation Analysis statistics Interpretation/Conclusion Presentation
Figure 1.CI2 Mandatory childhood vaccines? Whooping cough Polio Measles MMR & Autism? Wakefield falsified 1998 study 2010 - Lancet retracts study Are you for or against mandatory childhood vaccines? If you had children, will you vaccinate them? Thimerosal