Introduction to Biology Biology and Science Biology The

Introduction to Biology

Biology and Science Biology The study of life. From the Greek - Bios - "Life" Logos (logy) - "word or reason" - study of

Biology and Science Branches of biology Botany - study of plants Zoology - study of animals Anatomy - study of the structure of living things. Taxonomy - study of the classification of living things. Genetics - study of heredity. Physiology - study of the functions of living things. Microbiology - study of organisms at microscopic level

Biology and Science Body of knowledge gained by observation and experiment. Pure Science Basic research; Answers questions Applied Science Uses knowledge gained in basic research Solve practical problems Other sciences important to biology Chemistry - study of matter, structure and its changes Physics - relationship between matter and energy.

Scientific Investigations Scientific Method Logical, orderly way to solve a problem or answer a question. Steps State the Problem Gather Information on Problem Form a Hypothesis Experimentation Observe and Record Data from the Experiment. State a Conclusion Accurately Report Research Methods, Results, and Conclusions

Scientific Investigation State the Problem Define what you are trying to discover Gather Information on Problem Collect/study previous information May already have been answered. Usually library research/Internet Studies

Scientific Investigation Form a Hypothesis - working explanation or trial answer an "educated guess" Based on the available information. Attempts to explain the observed facts. Tested many times before acceptance May have to be changed if test results don't support the hypothesis

Scientific Investigation Experimentation or Test the Hypothesis Experiment Test to prove or disprove the hypothesis. Experimental Factor/Variable What you are trying to answer Test only one variable at a time Independent Factor – changes by itself Dependent Factor – changes because other factors Control Tested the same as the experimental part except experimental factor is omitted

Scientific Investigation Observe and Record Data from the Experiment. The results. Includes: Notes, drawings, tables, graphs, or other forms of information.

Scientific Investigation State a Conclusion Based on the facts observed in experiment. Answer to your problem. Theory - Best explanation to the problem Hypothesis that has been supported by experimental evidence over and over Strengthen or weakened by new data. Law - the way nature behaves.

Scientific Investigation Accurately Report Research Methods, Results, and Conclusions Publish report. Informs others of the new information Saves time, effort, money, and speeds progress.

Scientific Investigation Microscopes History of development Middle Ages - single lens magnifying glasses 1590 ‘s - Janssen brothers, Dutch eyeglass makers First known compound microscope Two lenses at opposite ends of a tube. Anton van Leeuwenhoek Used to his microscopes to observe many different things including bacteria Considered beginning of microbiology.

Scientific Investigation Types of Microscopes Compound Light Microscope Uses visible light to light specimen Must consist of 2 lenses – most have many Eyepiece lens Objective lenses Electron Microscopes Use beam of high speed electrons to illuminate specimen Types Transmission Electron Microscope (TEM) Electron beam passes through specimen Magnifies about 200, 000 x. Scanning Electron Microscope (SEM) Electron beam bounces off surface Produces 3 -D images.

Scientific Investigation Attributes of a Microscope Magnification - increase in size of image of specimen Each lens shows number of times it will magnify; 10 x - 10 times; 40 x - 40 times Total magnification found by finding the product of eyepiece and objective magnifications eyepiece lens = 10 x objective lens = 40 x Total Magnification = 400 x (10 x 40) Greatest magnification about 2000 x with light microscope Resolution (Resolving Power) Measure of the clarity and sharpness of the image; ability to show close objects are really separate. More magnification usually mean poorer resolution.

Scientific Investigation Other Major Equipment Ultracentrifuge - spins materials at very high speeds Separates solids from liquids using centrifugal force. Chromatography - Separating substances in a mixture Uses differences in solubility of solids in a solvent Electrophoresis - separates due to electrical charges. Computers Make long, complex calculations; modeling. Organize data.

Characteristics of Life • • • Living things organize protoplasm Display Metabolism and Require Energy Respond to Environment Adapt to the Environment Exhibit Growth and Development. Capable of Reproduction

Characteristics of Life Living things organize protoplasm Protoplasm - special system of very complex compounds reacting Protoplasm is nonliving Doesn't have a definite composition Protoplasm organized into cells - common unit of life When parts of protoplasm work together producing chemical activity then life exists. Levels of organization Cell Tissue Organ System Organism

Characteristics of Life Display Metabolism and Require Energy All living things perform chemical activities Transform energy (ability to do work). Metabolism - all chemical reactions in an organism Anabolism – assembly of compounds; stores energy; Catabolism - breakdown compounds; energy released, Energy Relationships All energy for life comes from sunlight. Autotroph - makes its own food. Heterotroph - eats other organisms.

Characteristics of Life Metabolic Functions Ingestion - take in materials Digestion - breakdown of complex food materials. Assimilation – assembly of new materials Respiration - release of energy from food Aerobic - uses oxygen Anaerobic - without using oxygen. Excretion - waste material elimination.

Characteristics of Life Respond to Environment Stimulus Change in the environment. Response Action of an organism caused by stimulus. Irritability Ability of organism to respond to stimulus.

Characteristics of Life Adapt to the Environment Some organisms have characteristics that enable survival a harsh environment. Variations - differences in organisms. Adaptation - characteristic of an organism that enables it to live in its environment. Adapted organisms are capable of surviving and reproducing. Organisms don't instantly change.

Characteristics of Life Exhibit Growth and Development. Growth - increase in size Either cell size or cell number increases. Development - series of orderly changes in form and function. Occur from beginning to maturity and death of organism. Stages Beginning Growth Maturity Decline Death

Characteristics of Life Capable of Reproduction Process where organism makes more of its own kind. Necessary for species survival not individual. Prevents extinction of the species. Forms of reproduction Sexual - requires 2 parents Asexual - requires 1 parent

Abiogenesis/Biogenesis Spontaneous Generation - Abiogenesis Before mid 17 th century, many believed living things developed from nonliving materials. Frogs and eels - made from pond mud Rotting meat - turned into maggots then flies. Jean van Helmont, Belgian doctor, 1600's Recipe for mice Dirty shirt in container of wheat would produce mice in 21 days. Abiogenesis Idea that living organisms could develop from nonliving matter.

Abiogenesis/Biogenesis Principle of Biogenesis Idea that living things could develop only from other living things. Now part of Cell Theory Support for Biogenesis Francesco Redi's - 17 th C Italian physician John Needham's - 18 th C English scientist. Lazzaro Spallanzani's - 19 th C Italian biologist. Louis Pasteur's - 19 th C French chemist

Abiogenesis/Biogenesis Redi's Experiment - 17 th century Believed flies came from eggs laid by other flies. Place raw meat in jars - sealed some, left some open. Maggots (fly larvae) appeared in open jars; none in closed People argued that air needed, provided vital force. Repeated experiment - didn't seal jars Covered some with fine netting Maggots appeared in open jars; not in net covered jars Eggs found on the netting. Proved flies came from other flies.

Abiogenesis/Biogenesis Needham's Experiment - 18 th century Heated meat broth Believed boiling would kill all living things in broth. Allowed broth to cool then loosely sealed flasks. Found microorganisms in broth several days later. Concluded microbes appeared spontaneously.

Abiogenesis/Biogenesis Spallanzani's Experiment - 19 th century Believed Needham hadn't boiled broth long enough Boiled broth in sealed flasks for about 1 hour. After several days - no growth Opponents believe boiling destroys "active principle" Believed air was necessary Repeated experiment by boiling broth for different amounts of time Loosely covered them Microbes found in all flasks.

Abiogenesis/Biogenesis Pasteur's Experiment - 19 th century Earlier work with microbes was inconclusive how they formed. Pasteur believed air contained inactive microbes called spores. First experiment Boiled broth in sealed flasks Opened/placed them in places where the air was likely to contain varying amounts of dust and spores High/low altitudes Dusty/clean areas Greatest number of microbes found in flasks with greatest amount of dust Opponents questioned amount of air

Abiogenesis/Biogenesis Second experiment Pasteur prepared set of flasks with swan necks. Air could get to broth Boiled flasks of broth - allowed them to set Observed that dust had collected in the s-trap of flask's neck When flask tipped the so that the dust got into the broth, microbes appeared Some flasks sat for more that a year with no growth Showed boiling didn't destroy the broth's ability to grow microbes Showed that air didn't contain any "active principle" or "vegetative force" that gave rise to life.