CHAPTER 1 NOTES

THE SCIENCE OF LIFE

40 MILLION SPECIES ORGANISM- LIVING THING BIOLOGY- THE STUDY OF LIVING

THINGS

CHAPTER 1

SECTION 1

THE WORLD OF BIOLOGY

Characteristics of Life

Organization and Cells Response to Stimuli Homeostasis Metabolism Growth and Development Reproduction Change Through Time

Organization and Cells

CELLS- Basic unit of structure and function

ORGANIZATION- at both molecular and cellular levels- particular cells carry out specific functions

atoms molecules organelles cells organs organ systems organism

CELL STRUCTURE AND FUNCTION

Cell- basic unit of structure and function Unicellular organisms- one celled Multicellular organisms- more than one cell Cells are highly organized. Cell Differentiation- the development of

cells having special functions

STABILITY AND HOMEOSTASIS

Homeostasis- stable level of internal conditions

Metabolism

ENERGY USE– METABOLISM – sum of all chemical processes

that occur in an organism– Energy maintains organization

Growth and Development

GROWTH- result of cell division and enlargement– Development- process by which adult organism

arises (puberty)

REPRODUCTION AND INHERITANCE

REPRODUCTION- the production of new offspring

– transmits heredity info to offspring (DNA) – gene- a short segment of DNA that contains the

instructions for the development of a single trait Sexual reproduction- the production of offspring

from the combination of genetic material from two parent organisms

Asexual reproduction- the production of offspring that does not involve the union of gametes (sex cells)

EVOLUTION

Populations of organisms evolve or change over time.

Allows for survival in a changing world Assists with the diversity of organisms

Section 2

Themes in Biology

BIOLOGY THEMES

3 Themes in Biology– Diversity and Unity of Life– Interdependence of Organisms– Evolution of Life

Unity in the Diversity of Life

There are certain features that all living things have in common:– Genetic code = the rules that govern how cells

use the hereditary information in DNA– Presence of organelles

Three Domains of Life– Bacteria– Archae– Eukarya

6 Kingdoms– 4 in Eukarya (Protista, Fungi, Animalia, and

Plantae)– 1 in Arachae (Archae)– 1 in Bacteria (Bacteria)

INTERDEPENDENCE OF ORGANISMS

Ecology - the study of the interaction of organisms with one another and their environment

Ecosystems- environmental communities

Evolution of Life

Evolution = descent with modification- a process in which the inherited characteristics within populations change over generations such that genetically distinct populations and new species can develop

Natural selection = the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals

MATTER, ENERGY AND ORGANIZATION

Living things are composed of highly organized matter

Organization requires energy Photosynthesis- energy from sun is changed into a

form of energy that can be used by living things autotrophic- make their own food (producers) Heterotrophs- organisms that must take in food to

meet their energy needs (consumers)

CHAPTER 1 SEC. 3

THE STUDY OF BIOLOGY

Steps of the Scientific Method

Make an observation with the senses Ask a question about the observation Collect data Hypothesize Prediction Experiment Draw Conclusions Communicate

COLLECTING DATA

DATA- all info gathered in trying to answer a

question- includes:– Observation

Qualitative- what we see or gather with senses

– Measuring Quantitative- what we measure using instruments and

numbers

– Sampling- using a small part to represent the entire population; which must be large and random

– Organizing data- charts, graphs, tables, maps etc

HYPOTHESIS

DEFINITION- A STATEMENT THAT EXPLAINS A SCIENTIST’S OBSERVATIONS AND DATA AND CAN BE TESTED– Can be proved wrong, but can never be proved

beyond all doubt– Are often refined, revised or discarded based on

new evidence

PREDICTION

A STATEMENT MADE IN ADVANCE THAT STATES THE RESULTS THAT WILL BE OBTAINED FROM TESTING A HYPOTHESIS

“IF…..THEN……..

EXPERIMENT

DEFINITION: testing a hypothesis or prediction by gathering data under controlled conditions

CONTROLLED EXPERIMENT involves the following:– Control group- a group or individual that serves

as a standard of comparison with another group or individual to which it is identical except for one factor- “the norm”

(Experiment cont.)

– EXPERIMENTAL GROUP- group or individual that is exposed to the factor/variable

– INDEPENDENT VARIABLE- an experimentally manipulated variable- the one thing you are testing- that you change

– DEPENDENT VARIABLE- the responding variable in an experiment (results for action of the independent variable)

ANALYZING DATA FROM EXPERIMENT

IS DATA RELIABLE? OFFER SUPPORT? REJECT?

MAKE STATISTICS; COMPARE WITH OTHER STUDIES

LOOK FOR SOURCES OF ERRORS

DRAWING CONCLUSIONS

Model- an explanation supported by data Inference- a conclusion made on the basis

of facts or premises rather than on direct observations

Theory- a broad and comprehensive statement of what is believed to be true, supported by considerable experimental evidence from related hypothesis

COMMUNICATION

Report findings in journals, at meetings, etc. Allows scientists to repeat and/or expand on previous work

CHAPTER 1 SEC 4

TOOLS AND TECHNIQUES

MICROSCOPES

MAGNIFICATION- the increase of an object’s size to allow viewing

RESOLUTION- the power to show details clearly

FOUR BASIC TYPES OF MICROSCOPES:– Compound light microscope (LM)– Stereomicroscope– Transmission electron microscope (TEM)– Scanning electron microscope (SEM)

LIGHT MICROSCOPE

Light transfers through a thin specimen on a slide

Parts of light microscope– Stage- supports slide and specimen– Objective lens- enlarges t he image – Ocular lens- magnifies image even more– Nosepiece- holds and rotates the objectives– Diaphragm - changes the amount of light to

reach the specimen

– Course focus/adjustment- the focus to be used at lower powers- DO NOT USE AT HIGH POWER

– Fine focus/adjustment- the focus to be used at high power for more precise images

– Power of magnification- the total amount of magnification- ocular lens is 10 X

Multiply 10X by the objective lens– Ex. 10x X 40x = 400 power

Eye piece

Ocular lensBody tube

NosepieceObjective lens

StageDiaphragm

Light source

Course adjustment

Fine adjustment

Base

STEREOMICROSCOPE

Used to view larger objects Usually only has 2 objectives- ours has a 5

and 10 power

TRANSMISSION ELECTRON MICROSCOPE

Transmits a beam of electrons through a thin slice

Focuses on a screen or photographic plate Can magnify up to 200,000 times BUT cannot be used to view live specimens

SCANNING ELECTRON MICROSCOPE

Three-dimensional images- no living Specimens are not sliced- but are sprayed

with a metal coating which emits a shower of electrons when the beam of electrons is passed over it

Electrons are passed onto a photographic plate

Magnify up to 100,000 times

MEASUREMENT

SI= Systeme International d’Unites BASE UNITS-

– Length = meter = m– Mass = kilogram = kg– Time = second = s– Electric current = ampere = A– Temperature = Kelvin = K– Amount of substance = mole = mol– Volume = liter = l

Metric Prefixes

Based on the power of ten– Kilo 1000– Hecto 100– Deka 10– Meter, liter,gram– Deci .1– Centi .01– Milli .001– Micro .000001– Nano .000000001

Units

DERIVED UNITS- when two base units combine– Volume= m3

LAB SAFETY

http://www.youtube.com/watch?v=z_J9wMSbkZI

http://www.youtube.com/watch?v=KR-PyIrcwaU

http://www.youtube.com/watch?v=ug8j_0mNRfs