Biology Lecture 1 PDF

Topic 1 Introduction to the Science of Life and Levels of Organization PowerPoint Lec tures for Biology, Seve nth Edition Neil Campbell and Jane Reece Lectures by Chri s Romero Copyright © 2005 Pearson Edu cation, Inc. publishing as Benjamin Cummings  Learning Objectives (...

Topic 1 Introduction to the Science of Life and Levels of Organization PowerPoint Lec tures for Biology, Seve nth Edition Neil Campbell and Jane Reece Lectures by Chri s Romero Copyright © 2005 Pearson Edu cation, Inc. publishing as Benjamin Cummings  Learning Objectives (LOBs) 1. Identify the levels of organization of living organisms (biological hierarchy). 2. Describe the properties of living organisms. 3. Identify the classification of living organisms (taxonomy). 4. Explain Darwin’s theory on the origin of species (evolution) including its two main concepts (natural selection and decent with modification) Reading: Campbell Biology Chapter 1 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Did you ever wonder… Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  How does a cell work? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  What is cancer and how is it caused? Breast cancer Huang Chuncai (Neurofibromatosis) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Why do we need to eat fruits and vegetables? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Why do we need to exercise? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Why do we look like our parents? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Why do we grow old? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  All of the above questions can be answered by studying Biology Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  What is Biology? Biology is the scientific study of life: looks for answers to the question of what is life and how it works Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  What is Biology? Biology is the scientific study of life: – how a single cell develops into an animal – how plants convert sunlight into sugars – how life evolved from microbes to humans – environmental issues Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Properties of living organisms (b) Evolutionary (a) Order adaptation (c) Response to the environment (e) Energy (d) Regulation processing (g) Reproduction (f) Growth and Figure 1.2 development Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Properties of living organisms 1. All living organisms are composed of cells 2. Reproduction (using DNA) 3. Growth and development 4. Capable of energy processing (absorb energy from their environment) 5. Sense their environment and respond to environmental signals 6. Regulation (e.g. homeostasis) 7. Evolutionary adaptation (evolution) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 1. All living organisms are made of cells Unicellular organisms: made of 1 cell Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  1. All living organisms are made of cells Multicellular organisms: made of more than one cell Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  2. Living organisms reproduce using DNA Genetic material – Transferred from parents to offsprings – DNA: deoxyribonucleic acid Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 3. Living organisms grow and develop DNA used as a blueprint Organisms develop and grow in complexity Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  3. Living organisms grow and develop Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  4. Living organisms absorb energy from their environment Plants: autotrophs - perform photosynthesis - convert sunlight to chemical energy (sugars) Animals: heterotrophs - Do not perform photosynthesis - Use energy from their food Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  5. Response to environmental signals Living organisms smell, listen, taste, touch and see their surroundings Some organisms can see and feel things that humans cannot Some organisms have a great sense of direction (unlike humans) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  6. Regulation of their systems Homeostasis: maintenance of constant internal conditions Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  7. Evolutional adaptation Evolution: changes in organisms over successive generations (over time) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Hierarchy of Biological Organization Βiological hierarchy: The study of life extends from the microscope scale of molecules and cells to the global scale of the entire living planet Importance: understanding the hierarchy of biological organization helps us to understand the interactions from the molecular level to biosphere level Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Hierarchy of Biological Organization 1 The biosphere From the biosphere to organisms 2 Ecosystems 3 Communities 4 Populations 5 Organisms Figure 1.3 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Hierarchy of Biological Organization From cells to molecules 9 Organelles 1 µm Cell 8 Cells Atoms 10 µm 10 Molecules 7 Tissues 50 µm 6 Organs and organ systems Figure 1.3 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Hierarchy of Biological Organization Organism Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Biological Hierarchy Molecules: e.g. DNA and proteins Cells: many different cell types in multicellular organisms Tissues: made by different types of cells Organs: made by different types of tissues - e.g. heart, brain Organ system: made by many different types of organs - e.g. heart and blood vessels: work together to pump blood (cardiovascular system) Οrganism: an individual form of life, e.g. a specific plant, an animal, a bacterium, etc. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Biological Hierarchy Population: a group of organisms of the same type (species) living in a certain area Community: groups of different species or organisms living together in the same area Ecosystems: the communities and their physical environment (e.g. a tropical coral reef) Biomes: large areas defined by distinct characteristics (e.g. dessert biome, tropical rainforest biome, coral reefs) Biosphere: our planet Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Ecosystem Dynamics The dynamics of any ecosystem include 2 major processes: – Cycling of nutrients: materials acquired by plants eventually return to the soil – Energy flow: sunlight → producers → consumers Producers: organisms that convert light energy to chemical energy (perform photosynthesis) Consumers: feed on producers or other consumers (cannot perform photosynthesis) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Energy flows through an ecosystem Usually entering as sunlight and exiting as heat Sunlight Ecosystem Producers (plants and other photosynthetic organisms) Heat Chemical energy Consumers (including animals) Figure 1.4 Heat Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Cell Cell: the basic structural and functional unit of every organism The cell is the lowest level of organization that can perform all activities required for life Figure 1.5 25 µm Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Genetic material: The Cell’s Heritable Information Cells contain chromosomes which partly consist of DNA Each chromosome contains thousands of genes Genes: – direct the production of proteins (gene expression) – transmit information from parents to the offspring Sperm cell Nuclei containing DNA Fertilized egg Embryo’s cells with DNA from with copies of both parents inherited DNA Egg cell Offspring with traits inherited from Figure 1.6 both parents Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The molecular structure of DNA The entire set of genetic information in a cell is called the genome Nucleus DNA The sequence of Each Cell nucleotides (A, T, C, G) A chromosome C in genes contains the Nucleotide contains T A information for building hundreds or T A the cell’s molecules thousands of C C genes G T A G T A (a) DNA double helix. This model shows (b) Single strand of DNA. These geometric shapes and each atom in a segment of DNA.Made letters are simple symbols for the nucleotides in a up of two long chains of building small section of one chain of a DNA molecule. blocks called nucleotides, a DNA Genetic information is encoded in specific sequences molecule takes the three-dimensional of the four types of nucleotides (their names are Figure 1.7 form of a double helix. abbreviated here as A, T, C, and G). Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cell types: Two Main Forms of Cells All cells share certain characteristics – They are all enclosed by a membrane – They all use DNA as genetic information Two types (forms) of cells make up every organism – Prokaryotic (Bacteria and Archaea domains) – Eukaryotic (Protists, Fungi, Plants, Animals kingdoms) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Prokaryotic versus Eukaryotic cells Eukaryotic cells have a nucleus which contains the DNA and are subdivided by internal membranes into various membrane-enclosed organelles. Prokaryotic cells lack a nucleus and membrane-enclosed organelles EUKARYOTIC CELL PROKARYOTIC CELL DNA (no nucleus) Membrane Membrane Cytoplasm Organelles Figure 1.8 1 µm Nucleus (contains DNA) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Prokaryotic-Eukaryotic cell morphology Prokaryotic cell Eukaryotic cell Lysosome Εndoplasmic reticulum Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Grouping Species: Taxonomy To understand the diversity of life, biologists classify species into groups which are then combined into broader groups (depending on how closely they are related) Taxonomy: the branch of biology that names and classifies species according to a system of broader and broader groups Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Classifying living organisms Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya Figure 1.14 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Classifying living organisms Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Organism nomenclature: Binomial nomenclature Carolus Linnaeus (1707-1778): Swedish botanist - founder of taxonomy (branch of biology that classifies organisms) - developed binomial nomenclature of species (e.g. Homo sapiens) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Organism nomenclature: Binomial nomenclature Species (organism) name = Genus + characteristic property Examples: Staphylococcus aureus (a bacterial species) genus characteristic property Homo sapiens genus characteristic property Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Three Domains of Life At the highest level, life is classified into three domains: – Bacteria – Archaea – Eukarya Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Three Domains of Life Living organisms: consist from either 1 or more cells (unicellular or multicellular) Domain Bacteria and domain Archaea: consist of unicellular prokaryotes Domain Eukarya, the eukaryotes, is divided into 4 kingdoms – Protists: mostly unicellular eykaryotes(include Protozoa and Algae) – Fungi: unicellular (e.g. yeasts) or multicellular (e.g. mushrooms) eukaryotes – Plants: multicellular eukaryotes – Animals: multicellular eukaryotes Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Life’s three domains Kingdom Plantae consists Bacteria are the most di4veµmrse Protists (multiple kingdom100sµ)m of multicellular eukaryotes and widespread prokaryotes are unicellular eukaryotes and that carry out and are now divided among some simple multicellular photosynthesis, the multiple kingdoms. relatives. Scientists are currently conversion debating how to split the protists DOMAIN ARCHAEA of light energy to food. into several kingdoms Live in extreme environments0,.5sµumch Kindom Fungi is defined in part Kindom Animalia consists as salty lakes and boiling hot by the nutritional mode of its of multicellular eukaryotes springs. Domain Archaea includes members, such as this mushroom, that ingest other organisms. multiple kingdoms. The photo showswhich absorb nutrients after Figure 1.15 a colony composed of many cells. decomposing organic material. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Βasic categories of living organisms Prokaryotic Εukaryotic Μicro- Αrchaea Protists οrganisms Βacteria Fungi Μacro- Do not exist Animals οrganisms Plants Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Originally living organisms were divided in five kingdoms, later in 3 domains Prokaryotic cells Eukaryotic cells (Domain Eukarya) Monera (Previously Kingdom) Kingdoms: Protists Bacteria Archaebacteria Fungi (Domain) (Domain Archaea) Plants Animals Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The (previously) five kingdoms descended from the same ancestor Plants Animals Fungi Eukaryotes Protists Bacteria and Prokaryotes Archaea Copyright © 2005 Pearson Educa tion, Inc. publishing as Benjamin Cummings  The evolutionary view of life Evolution is the change in the inherited characteristics of biological populations over successive generations 1859: Charles Darwin published his theory On the Origin of Species by Natural Selection Figure 1.18 Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Origin of Species: 2 main points 1. Descent with modification Contemporary species arose from a succession of ancestors Modifications happened along the way 2. Natural selection Individuals who are better fit will survive and reproduce A population will have an increasing proportion of individuals with “better” traits Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Descent with modification Homo sapiens Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Natural Selection Darwin proposed natural selection as the mechanism for evolutionary adaptation of populations to their environments Population of organisms Overproduction Hereditary and struggle for variations existence Differences in reproductive success Evolution of adaptations Figure 1.20 in the population Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Natural Selection Natural selection is the evolutionary process that occurs when a 1 Populations with varied inherited traits population’s heritable variations are exposed to environmental factors that favor the 2 Elimination of individuals with certain traits. reproductive success of some individuals over others 3 Reproduction of survivors. Figure 1.21 Population of beetles. Initially, the population varies extensively in terms of their color, from very light to very dark. 4 Increasing frequency of traits that enhance Birds can more easily spot the beetles that survival and reproductive success. are lightest in color Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The tree of life Darwin proposed that natural selection could enable an ancestral species to “split” into 2 or more descendant species, resulting in a “tree of life” Each species is on a twig of a branching tree of life extending back in time through ancestral species more and more remote All of life is connected through its long evolutionary history Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The tree of life Evolution of finches Large Small Large ground finch ground tree finch Large cactus ground finch finch Geospiza Camarhynchus Green Gray magnirostris Geospiza warbler warbler psitacula Medium Sharp-beaked Medfuiulimginosa Woodpecker finch finch ground finch Geospiza ground finch tree finch conirostris GeospizaCactus finch Certhidea Certhidea Cactospiza Camarhynchus difficilis ground finch pauper olivacea fusca Geospiza Mangropvaellida Small tree finch fortis finch Geospiza Camarhynchus scandens Cactospiza heliobates parvulus Seed eater Cactus flower Seed eater Vegetarian eater finch Platyspiza crassirostris Insect eaters Bud eater Ground finches Tree finches Warbler finches Common ancestor from Figure 1.23 South American mainland Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Scientific Method: Forming and Testing a Hypothesis Biologists use various forms of inquiry to explore life Inquiry: a search for information and explanations, often focusing on specific questions Hypothesis-Based Science: - In science, inquiry that asks specific questions usually involves the proposing and testing of hypothetical explanations (hypotheses) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Scientific Method Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Role of Hypotheses in Scientific Inquiry Scientific hypothesis: the answer to a given question, an explanation on trial Makes predictions that can be tested A scientific hypothesis must have 2 important qualities: – It must be testable – It must be falsifiable Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Hypothesis-Based Science We all use hypotheses in solving everyday problems Observations Questions Hypothesis # 1: Hypothesis # 2: Dead batteries Burnt-out bulb Prediction: Prediction: Replacing batteries Replacing bulb will fix problem will fix problem Test prediction Test prediction Figure 1.25 Test falsifies hypothesis Test does not falsify hypothesis Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Deduction: The “If…then” Logic of Hypothesis-Based Science Deductive reasoning: – The logic flows from the general to the specific If a hypothesis is correct, we can expect a particular outcome Designing controlled experiments: - Experiments must be designed to test the effect of one variable by testing control groups and experimental groups in a way that cancels the effects of unwanted variables Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Scientific theory and Limitations of Science Scientific theory: – broad in scope – generates new hypotheses – is supported by a large body of evidence Limitations of science: - Science cannot address supernatural phenomena - Reason: hypotheses must be testable and falsifiable and experimental results must be repeatable Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  What will we learn during MED-103? Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Living organisms consist of cells Organism Tissues Cells Human beings have 200 different types of cells. They were all created from one fertilized egg! Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Some interesting numbers The number of cells in the human body: 1013 The number of cells created during a lifetime: 1016 Death and creation of new cells: 107 / second Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Animals consist of cells Mouse cells (NIH3T3) fibroblasts) Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Plants consist of cells Onion cells Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cells can exist as independent organisms Bacterium Βacillus Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cells vary in their appearance and function Bacteria E.coli Onion cells Red blood cells Ovum Sperm cells Neuron cell Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  All organisms consist of cells and have a similar biochemistry Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Chemistry of Life Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The chemical basis of life Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Properties of Water Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The structure and function of large biological molecules Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Cell Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cell structure Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Membrane structure and function Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cell communication Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Introduction to metabolism Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Cellular respiration Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  The Cell Cycle and Mitosis Mitosis vs Meiosis Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Enjoy the wonderful world of Biology…. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Red Blood Cells Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Summary Properties of living organisms 2 different cell forms: Eukaryotic vs Prokaryotic cells Biological hierarchy: organisation of living organisms from the molecular level to biosphere level Taxonomy: classification of living organisms according to how closely they are related (Domain → Species) Darwin’s theory on the origin of species (evolution): - Natural selection - Decent with modification The scientific method: Forming and testing a hypothesis Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  Midterm and Final exams You will be examined using SBAs and SAQs SBA= Single Best Answer questions (multiple choice questions- 5 answer choices) - Only 1 correct answer - No negative marking SAQs= Short Answer Questions Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings  SBA (Short Best Answer) example Which type of organism is a unicellular prokaryote? A. Bacteria B. Protists C. Fungi D. Animals E. Plants Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings