Biology: Exploring Life

Transcription

1 Chapter 1 Biology: Exploring Life PowerPoint Lectures for Biology: Concepts and Connections, Fifth Edition Campbell, Reece, Taylor, and Simon Lectures by Chris Romero 1. Go to: 2. Click on the Pelican Book (the 5 th Edition of your book) 3. Login using the following login: Login Name: mpietrangelo Password: mpietrangelo1 1

2 Community All organisms on the Florida coast Spinal cord Nerve Biosphere Population Group of brown pelicans Ecosystem Florida coast Brain Organism Brown pelican Tissue Nervous tissue Cell Nerve cell Organ system Nervous system Nucleus Organelle Nucleus Organ Brain Atom Molecule DNA THE SCOPE OF BIOLOGY 1.1 Life s levels of organization define the scope of biology Life s structural hierarchy Defines the scope of biology, the scientific Biosphere study of life Ecosystem Florida coast Community All organisms on the Florida coast Population Group of brown pelicans Organism Brown pelican Spinal cord Organ system Nervous system Nerve Brain Tissue Nervous tissue Organ Brain Figure 1.1 Cell Nerve cell Nucleus Atom Organelle Nucleus Molecule DNA 2

3 An ecosystem consists of all the organisms living (BIOTIC) in a par ticular area As well as the nonliving (ABIOTIC) environmental components All the living organisms in an ecosystem Make up a community A population Consists of a localized group of individuals of a species An individual living entity Is an organism 3

4 The hierarchy continues downward with Organ systems Organs Tissues Cells Organelles Molecules THE PROCESS OF SCIENCE 1.2 Scientists use two main approaches to learn about nature Science Is a way of knowing Seeks natural causes for natural phenomena 4

5 Discovery Science In discovery science Scientists describe some aspect of the world and use inductive reasoning to draw general conclusions Hypothesis-Based Science (Hypothetico-Deductive Reasoning) In hypothesis-based science Scientists attempt to explain obser vations by testing hypotheses 5

6 1.3 With the scientific method, we pose and test hypotheses Hypothesis-based science involves Obser vations, questions, hypotheses as tentative answers to questions Deductions leading to predictions, and then tests of predictions to see if a hypothesis is falsifiable A Case Study from Ever yday Life Deductive reasoning is used in testing hypotheses as follows If a hypothesis is correct, and we test it, then we can expect a par ticular outcome Observations Question Hypothesis # 1: Dead batteries Hypothesis # 2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test prediction Figure 1.8A Test falsifies hypothesis Test does not falsify hypothesis 6

7 A Case Study from Biological Science In experiments designed to test hypotheses The use of control groups and experimental groups helps to control variables Observations: 1. Jumping spiders wave their legs in the presence of potential competitors. 2. Certain fly species, when approached by jumping spiders, wave their wings, which have markings that resemble spider legs. Question: What is the function of the flies wing markings and waving behavior? Hypothesis: The markings and wing waving increase survival of the flies by causing jumping spiders to flee. 7

8 Prediction: If this hypothesis is correct, Experiment: and the flies wings are masked with a dye, Predicted Result: then jumping spiders should pounce on the experimental flies more often that they do on control flies with normal wings. 1.4 The diversity of life can be arranged into three domains Organisms are grouped (classified) Into the prokaryotic domains Bacteria and Archaea and the eukaryotic domain Eukarya 8

9 Domain Bacteria prokaryotic cells composed of cells that lack a true, membranebound nucleus Figure 1.5A SEM 3,250 typically unicellular Domain Archaea prokaryotic cells composed of cells that lack a true, membrane-bound nucleus Figure 1.5B SEM 25,000 9

10 Domain Eukarya includes Protists (protozoans and algae, falling into multiple kingdoms) The kingdoms Fungi, Plantae, and Animalia Kingdom Fungi 275 Protists (multiple kingdoms) Kingdom Animalia Figure 1.5C Kingdom Plantae Protists typically unicellular were traditionally classified as Kingdom Monera but new studies indicate that is inaccurate and scientists are debating how many kingdoms Protists should be divided into 10

11 Fungi includes molds, yeasts, and mushrooms decompose the remains of dead organisms and absorb nutrients from the leftovers Plantae consists of plants typically photosynthetic comprised of cells that have thick, cellulose, cell walls 11

12 Animalia eat other organisms comprised of cells that have a cell membrane, but lack a rigid, cell wall typically motile (able to move) 12