The Scientific Study Of Life

Chapter 1

Objectives

Outline the universal characteristics of living Outline the universal characteristics of living thingsthings

Describe the Scientific Classification SystemDescribe the Scientific Classification System Outline the Scientific Method as a processOutline the Scientific Method as a process

Chapter 1 Page1 Biology is the study of lifeBiology is the study of life Living organisms have several properties and common Living organisms have several properties and common

characteristicscharacteristics Exhibit orderExhibit order

Ability to reproduceAbility to reproduce Ability to grow and developAbility to grow and develop Utilization of energy ( metabolism)Utilization of energy ( metabolism) response to external environmental stimuliresponse to external environmental stimuli Ability to adaptAbility to adapt

Chapter 1 Page2

Living organisms have several properties Living organisms have several properties and common characteristics con’tand common characteristics con’t Maintenance of homeostasisMaintenance of homeostasis Homeostasis maintains living systems in an Homeostasis maintains living systems in an

acceptable rangeacceptable range

Chapter 1 Page 3 Cell: most basic structure in living organisms, Cell: most basic structure in living organisms,

capable of carrying out all of the activities capable of carrying out all of the activities fundamental to lifefundamental to life

Cell is the structural and functionalCell is the structural and functional unit of life unit of life

Robert Hooke, an English Scientist, Robert Hooke, an English Scientist, First described and named cells in 1665.First described and named cells in 1665.

There are two main types of cells: Prokaryotes and There are two main types of cells: Prokaryotes and EukaryotesEukaryotes

Chapter 1 Page 4

Characteristics of ProkaryotesCharacteristics of Prokaryotes bacteriabacteria lack many of the organelles of eukaryoteslack many of the organelles of eukaryotes smallersmaller many have cell wallsmany have cell walls

Chapter 1 Page 5

Characteristics of EukaryotesCharacteristics of Eukaryotes plants,plants, animals,animals, fungi, protistafungi, protista membrane bound well defined nucleusmembrane bound well defined nucleus complex organelles complex organelles cell wall only in plantscell wall only in plants

Prokaryotes Vs Eukaryotes

Chapter 1 Page 6

Cells are organized in tissues,Cells are organized in tissues, organs, organs, organ systems, organ systems, individuals, individuals, populations, populations, communitiescommunities and ecosystems and ecosystems

Chapter 1 Page 7

Biologists classify organisms into groups Biologists classify organisms into groups with similar characteristics to understand with similar characteristics to understand the diversity of lifethe diversity of life

Classification of organisms = taxonomyClassification of organisms = taxonomy The system progresses from the most The system progresses from the most

general to the most specificgeneral to the most specific

Chapter 1 Page 8

The “system”The “system”KingdomKingdom

PhylumPhylumClassClass

OrderOrder FamilyFamily GenusGenus SpeciesSpecies

TheSystem

Based on information obtained the System Based on information obtained the System has been modified and is much more has been modified and is much more complicated than we will take time to complicated than we will take time to explain in our class. explain in our class.

There are now several Domains above the There are now several Domains above the Kingdom Level – Please read about themKingdom Level – Please read about them

Chapter 1 Page 9

For our purposes we will discuss the Five For our purposes we will discuss the Five Basic Kingdoms:Basic Kingdoms: Monera = BacteriaMonera = Bacteria Protista = unicellular eukaryotesProtista = unicellular eukaryotes Plantae = plantsPlantae = plants Fungi = mushrooms, slime molds, fungiFungi = mushrooms, slime molds, fungi Animalia = animalsAnimalia = animals

Chapter1 Page 10

Science means to know in LatinScience means to know in Latin Scientific Method specifies a process used Scientific Method specifies a process used

to find answersto find answers there are many different approachesthere are many different approaches

Chapter1 Page 11

Scientific Process ( Method)Scientific Process ( Method) Review accumulated scientific dataReview accumulated scientific data Formulate hypothesisFormulate hypothesis Experiment and observe to collect dataExperiment and observe to collect data Evaluate resultsEvaluate results

Chapter1 Page 12

Facts to remember regarding hypothesesFacts to remember regarding hypotheses They reflect past experience with similar They reflect past experience with similar

questionsquestions Propose multiple hypotheses whenever possiblePropose multiple hypotheses whenever possible Hypotheses should be testable via scientific Hypotheses should be testable via scientific

processprocess Hypotheses can be eliminated, but not proven Hypotheses can be eliminated, but not proven

with 100% certaintywith 100% certainty

Hypotheses Con’t HH0 0 = There is no difference

Example: There will be no difference in the stalking behavior of lions born in zoos and lions born in the wild

HA = There is a difference

Example: Lions born in the wild will stalk prey more efficiently than those born in zoos.

Positive and Negative Feedback

Used to regulate function in many Used to regulate function in many biological systemsbiological systems

Prevents was of energy and biochemicals in Prevents was of energy and biochemicals in living systemsliving systems

Helps maintain homeostasisHelps maintain homeostasis

Positive and Negative Feedback