A View of Life Chapter 1

Learning Objective 1 What are the three basic themes of biology? What are the three basic themes of biology? 1. Evolution 2. Information Transfer 3. Energy for Life

3 Basic Themes of Biology Evolution Populations change over time Information Transfer Genetic information is transferred: Within cells Within cells Within organisms Within organisms Among organisms Among organisms From one generation to another From one generation to another Energy for Life Energy flows From the SUN to Earth From the SUN to Earth From producers to consumers From producers to consumers

Learning Objective 2 What characteristics distinguish living organisms from nonliving things? What characteristics distinguish living organisms from nonliving things?

Cell Structure Plasma membrane Plasma membrane Surrounds and protects cell Surrounds and protects cell Separates cell from environment Separates cell from environment DNA DNA Codes genetic instructions Codes genetic instructions Organelles Organelles Internal structures for special functions Internal structures for special functions

Two Types of Cells Prokaryotic cells Prokaryotic cells Bacteria and archaea Bacteria and archaea Single celled organisms Single celled organisms No membrane-bound organelles No membrane-bound organelles Eukaryotic cells Eukaryotic cells Organelles enclosed by membranes Organelles enclosed by membranes Nucleus contains DNA Nucleus contains DNA

Organisms Grow and Develop Biological growth Biological growth Increases size and/or number of cells Increases size and/or number of cells Development Development Changes that take place during an organism’s lifetime Changes that take place during an organism’s lifetime

Organisms Regulate Their Metabolic Processes Metabolism Metabolism All the chemical activities of the organism All the chemical activities of the organism Homeostasis Homeostasis Homeostatic mechanisms regulate and balance the internal environment Homeostatic mechanisms regulate and balance the internal environment

Organisms Respond to Stimuli Stimuli Stimuli Physical or chemical changes in the internal or external environment Physical or chemical changes in the internal or external environment Cause the organism to respond Cause the organism to respond

Fig. 1-2, p. 4

Fig. 1-3a, p. 4

Fig. 1-3b, p. 4

Organisms Reproduce Asexual reproduction Asexual reproduction Low genetic variability Low genetic variability Sexual reproduction Sexual reproduction High genetic variability High genetic variability

Populations Evolve and Become Adapted to the Environment

What are the Characteristics of Life? 1. Composed of cells Prokaryotic vs Eukaryotic Prokaryotic vs Eukaryotic 2. Grow and Develop 3. Metabolism and Homeostasis 4. Respond to Stimuli 5. Reproduce 6. Evolve

Learning Objective 3 What are the hierarchical levels of biological organization? What are the hierarchical levels of biological organization?

How are you the “organism” arranged?

The Hierarchy of Biological Organization

Nucleus Organism Organ system Organ Tissue Cell Organelle Macromolecule Molecule Population Community Ecosystem Biosphere Water Oxygen atom Hydrogen atoms Bone cells Fig. 1-6, p. 7

Learning Objective 4 What is the importance of information transfer to living organisms? What is the importance of information transfer to living organisms?

DNA Transmits information from one generation to the next Transmits information from one generation to the next Contains 4 types of nucleotides Contains 4 types of nucleotides Makes up genes Makes up genes Codes for proteins Codes for proteins

The DNA Molecule

Information is Transmitted Chemical and electrical signals Chemical and electrical signals Proteins Proteins Hormones Hormones Cell signaling Cell signaling Neurotransmitters Neurotransmitters

Evolution: The Unifying Concept of Biology Theory of Evolution Theory of Evolution Explains changes in populations over time Explains changes in populations over time Evolution Evolution Processes by which populations change overtime Processes by which populations change overtime

Learning Objective 5 What is the binomial system of nomenclature used to classify living organisms? What is the binomial system of nomenclature used to classify living organisms?

Organizing the Study of Life Systematics Systematics Study of organisms and their evolutionary relationships Study of organisms and their evolutionary relationships Taxonomy Taxonomy Science of naming and classifying organisms Science of naming and classifying organisms Species Species Populations capable of breeding with one another Populations capable of breeding with one another

Taxonomic Classification is Hierarchical DomainKingdomPhylumClassOrderFamily

Taxonomic Classification

Learning Objective 6 What are the 3 domains and What are the 3 domains and 6 kingdoms of living organisms?

Tree of Life

Fungi Six Kingdoms: BacteriaEukaryaArchaea BacteriaArchaeaProtistaPlantaeAnimalia Common ancestor of all organisms Fig. 1-9, p. 12 Three Domains:

Three Domains Bacteria Bacteria Archaea Archaea Eukarya Eukarya

Six Kingdoms Archaea Archaea Bacteria Bacteria Protista Protista Plantae Plantae Fungi Fungi Animalia Animalia

Learning Objective 7 What is the theory of evolution, and why is it the unifying principle of biology? What is the theory of evolution, and why is it the unifying principle of biology?

Adaptation Interactions between environmental conditions and genes Interactions between environmental conditions and genes Takes place over many generations Takes place over many generations An evolutionary process An evolutionary process

Learning Objective 8 How can natural selection cause adaptations to evolve? How can natural selection cause adaptations to evolve?

Natural Selection Theory of natural selection Theory of natural selection Charles Darwin and Alfred Wallace Charles Darwin and Alfred Wallace Applies to populations, not individuals Applies to populations, not individuals

Darwin’s 4 Observations 1. Individuals of a species vary 2. More offspring are produced than survive 3. Organisms compete for resources; some are better adapted to succeed 4. Best-adapted individuals survive to reproduce

Mutations Chemical or physical changes in DNA Chemical or physical changes in DNA Can be inherited Can be inherited Cause genetic variation Cause genetic variation

Evolution Process by which populations change over time as a result of selective pressures from changes in environment Process by which populations change over time as a result of selective pressures from changes in environment

Gene Pool All the genes in a population All the genes in a population

Fig. 1-11a, p. 13

Fig. 1-11b, p. 13

Fig. 1-11c, p. 13

Learning Objective 9 What are the roles of producers, consumers, and decomposers in the flow of energy through ecosystems? What are the roles of producers, consumers, and decomposers in the flow of energy through ecosystems?

Energy for Life Life depends on energy from the sun Life depends on energy from the sun

OTHER ACTIVITIES Homeostasis Movement of materials in and out of cells Growth and development Reproduction NUTRITION Nutrients SYNTHESIS Manufacture of needed materials and structures Energy CELLULAR RESPIRATION Biological process of breaking down molecules Some used as raw materials Some used as fuel Fig. 1-12, p. 14

Energy Flow

Consumer (robin) Light energy Food Consumer (caterpillar) Producer (plant) Plant litter, wastes Soil Decomposers (bacteria, fungi) Heat Dead bodies Fig. 1-13, p. 14

Autotrophs Producers (autotrophs) Producers (autotrophs) Make their own food Make their own food Transform light energy to chemical energy through photosynthesis Transform light energy to chemical energy through photosynthesis Photosynthesis Photosynthesis CO 2 + water + light → sugars + oxygen

Heterotrophs Consumers (heterotrophs) use energy stored by producers through cellular respiration Consumers (heterotrophs) use energy stored by producers through cellular respiration sugars + oxygen → CO 2 + water + energy Decomposers (heterotrophs) break down wastes and dead organisms Decomposers (heterotrophs) break down wastes and dead organisms

Learning Objective 10 What procedures and terminology are used to test a hypothesis using the scientific method? What procedures and terminology are used to test a hypothesis using the scientific method?

The Process of Science Deductive reasoning draws specific conclusions based on information (facts) Deductive reasoning draws specific conclusions based on information (facts) Inductive reasoning draws general conclusions based on specific observations Inductive reasoning draws general conclusions based on specific observations

The Scientific Method Observation Observation Question or problem Question or problem Hypotheses Hypotheses Testable predictions Testable predictions Experiments Experiments Analyze data Analyze data Conclusions Conclusions

The Hypothesis A tentative explanation for observations A tentative explanation for observations Consistent with facts Consistent with facts Can be tested Can be tested Tests can be repeated by others Tests can be repeated by others Can be rejected Can be rejected Is falsifiable Is falsifiable

Testing Predictions by Experiment Prediction Prediction Deductive product of a hypothesis Deductive product of a hypothesis Control group Control group Closely matches experimental group Closely matches experimental group Experimental group Experimental group Differs from control group in 1 variable Differs from control group in 1 variable

Testing a Prediction

Amoeba dies Amoeba lives (a) Experimental group. When its nucleus is surgically removed with a microloop, the amoeba dies. (b) Control group. A control amoeba subjected to similar surgical procedures (including insertion of a microloop), but without actual removal of the nucleus, does not die. Fig. 1-17, p. 18

Interpreting Experiments Data analysis Data analysis

Sampling Error Can lead to inaccurate conclusions Can lead to inaccurate conclusions

Fig. 1-19a, p. 20

Single selection Marbles Curtain Actual ratio 20% blue 80% white 100% blue Assumption produces Fig. 1-19a, p. 20

Fig. 1-19b, p. 20

30% blue 70% white Marbles Curtain Actual ratio 20% blue 80% white Multiple selections produce Assumption Fig. 1-19b, p. 20

Scientific Theory An explanation of the natural world An explanation of the natural world Based on testable hypotheses Based on testable hypotheses Supported by reproducible observations Supported by reproducible observations