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Chapter 1:
Biology: the study of life
What is Life?
1.7 The Nature of Science
Science is way of knowing
Seeks causes for natural phenomena
Discovery Science
Inductive reasoning
Hypothesis Based Science
Deductive reasoning
All living things have common characteristics
Organization – and made up of cells
Response to Stimuli
Homeostasis
Metabolism
Growth and Development
Reproduction
Evolution-Change through Time
1.1 Characteristics of life
Section 1.1Levels of Organization
BIOSPHEREECOSYSTEM
COMMUNITY POPULATION
ORGANISM ORGAN SYSTEM
ORGANS TISSUES
CELL ORGANELLE
MOLECULE
ATOM
Section 1.1 – Organization- Cells are the
structural and functional units of life
Perform all activities required for life
Prokaryotic cell
Simpler, small
Eukaryotic cell
More complex larger
Nucleus
(contains DNA)
Eukaryotic
cell
Prokaryotic cell
DNA
(no nucleus)
Organelles
25,0
00
Distinguish between:
Metabolism versus homeostasis?
Growth and Development versus Evolution?
1.1 Characteristics of life
Diversity & Unity (all living things have certain traits in common)Three Domains – Archaea, Eubacteria, Eukaryota
Interdependence of Organisms
Evolution of Life
Natural Selection & Adaptation
1.2 Themes in Biology
1.2 Diversity of Life
Extent of diversity has led to classification schemes
K-P-C-O-F-G-S
Six Kingdoms Eubacteria
Archeabacteria
Protista-one-celled organisms
Fungi-mold and mushrooms
Plantae- multicellular plants
Animalia; multicellular animals
1
2
3
Populations with varied inherited traits
Elimination of individuals with certain traits
Reproduction of survivors
1.2 Evolution – Natural Selection
Section 1.2 Interdependence of organisms
Food Web
Producers
Consumers
Decomposer
Dynamic of an Ecosystem
Energy Flow
Recycling
chemical
nutrients
1) Observation
2) Hypothesis
3) Prediction
4) Experiment
5) Results (Data tables)
6) Conclusion/ Evaluation
7) Communication to scientific peers
1.3 Scientific Method
1) Observation
2) Hypothesis
3) Prediction
4) Experiment
5) Results (Data tables)
6) Conclusion/ Evaluation
7) Communication to scientific peers
1.3 Scientific Method
1.3 The Scientific Method
Make an observation
Ask a Question
Make a Hypothesis using all known information
Predict what the outcome would be if the hypothesis is valid
Test the hypothesis by experiments, models, and observations
Record results—DATA TABLES!!
Repeat the tests for consistency
Draw conclusions & suggestions for improvement
Communicate results
Hypothesis- an educated guess
Even if supported by a couple of experiments, it is not widely supported as a general rule
1.3 Law versus Theory
Theory-
Highly tested
Generally accepted principle --explains a vast number of observations and experimental data
1.3 Law versus Theory
Theory-
A theory explains how nature works.
Widely accepted
Explains vast amount of data
Synthesis –E.g., Theory of Evolution
Often non-mathematical (but may be math within studies supporting theory).
1.3 Law versus Theory
Law- describes what nature does under certain conditions
Predicts what will happen as long as those conditions are met.
Often times mathematically defined (once again, a description of how nature behaves)
1.3 Law versus Theory
Repetition - Trials
1. What is the purpose of repetition in science? a) To over come human error or randomness
b) Eg. Large sample populations, same experiment many times over with the same results.
2. Will repetition eliminate systematic errors?a) NO! A scientist has to allow for margin of error or
adjust, like aiming higher to compensate or mechanically adjust the scope.
Converting one metric unit to
another
k h da Basic unit d c m
(m, L, g)
To convert from one unit to another, move the decimal same direction and number of places the units are from each other 12 kilometers is ?? centimeters
centimeters are 5 places to the right
1,200,000 cm
134 decigrams is ?? hectograms hectograms are 3 places to the left
0.134 hg
Accuracy vs. Precision
Scientific Method –
Precision versus
Accuracy
Accuracy describes the nearness of
a measurement to the standard or
true value
4. Target Analogy to Sci. Method
1. Target is the expected outcome
2. The holes represent actual outcome
3. Precision and accuracy represent
analysis of results
4. In science we analyze expected vs.
actual outcomes and come to
conclusions
Accuracy vs. Precision
Scientific Method –
Precision versus
Accuracy
Precision is the degree to which
several measurements provide
answers very close to each other. It
is an indicator of the scatter in the
data and validity of your methods.
ACCURATE – Depends on YOU!
PRECISION– depends on the
equipment—the increments to which it is
marked
-the more decimal places marked to the
better
Three targets with three arrows each to shoot.
Can you hit the bull's-eye?
Both accurate and precise
Precise but not accurate
Neither accurate nor precise
How do they compare?
Can you define accuracy and precision?
Scientific Method - Graphing
Independent Variable
The variable you have control over
Dependent Variable
Changes in response to the independent
variable
Controlled Variables
Remain constant so results of the
experiment are valid
Nature’s Chemical Language
The rattlebox moth
Produces chemicals important for mating and
defense
Ch 3- The human body, as all of nature, is made of
chemical elements.
element: cannot be broken down to other substances by ordinary chemical means
Most common in human body (96%)
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N)
Trace element: small amount is essential
Ch 3 Elements can combine to form
compounds
Compound: a substance containing two
or more elements in a fixed ratio
More common than pure elements
ex. Vitamin A, Proteins
Sodium Chlorine Sodium Chloride
Ch 3 Atoms consist of protons, neutrons,
and electrons
Atom: the smallest unit of matter that
still retains the properties of an element
Three subatomic particles
Protons (p+) atomic nucleus
single positive charge
Neutrons part of the atomic nucleus they have no charge
Electrons (e-) have a negative charge; they circle around the nucleus
# of e = # of p
Atomic Number
Defines the element
equal to the number of of protons
Is equal to the number of electrons in a
neutral atom
Always the whole number
Atomic Mass
Is equal to the number of protons and
neutrons in the nucleus of the atom
(mass number)
May not be a whole number on the
periodic table
In biology you may round the atomic
mass to a whole number
Ch 3 - Radioactive isotopes can help or
harm us
Isotopes: different forms of atoms
Atoms with the same number of protons and electrons but a different number of neutrons
Radioactive isotopes
Nucleus decays spontaneously giving off particles of energy Research/Medicine
Radioactive tracers
Dangers Damage molecules (DNA)
Ch 3 Electron arrangement determines the
chemical properties of an atom
electron shells: certain energy levels where
electrons occur
Each shell holds up to a certain # of e-
Valence Shell Electrons
the # of e- in the outermost energy level
determines the chemical properties of an atom
(how it will bond w/other atoms)
Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)
Transferof electron
Protons +11
Electrons -11
Charge 0
Protons +17
Electrons -17
Charge 0
Protons +11
Electrons -10
Charge +1
Protons +17
Electrons -18
Charge -1
Section 2-1
Figure 2-3 Ionic Bonding
Ionic bonding
Transfer of Electrons from one atom to another
Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na+) Chloride ion (Cl-)
Transferof electron
Protons +11
Electrons -11
Charge 0
Protons +17
Electrons -17
Charge 0
Protons +11
Electrons -10
Charge +1
Protons +17
Electrons -18
Charge -1
Section 2-1
Figure 2-3 Ionic Bonding
Rules for drawing covalent bonded
molecules
2 electrons 1 bond 1 line
You can form more than one bond between
atoms
Carbon 4 bonds
Oxygen always has 2 bonds and 2 lone pairs
Hydrogen always has 1 bond
Nitrogen has 4 bonds or 3 bonds and a lone
pair of electron
some organic molecules
Methane Acetylene Butadiene Benzene Isooctane
CHAPTER 3.1 - Carbon Compounds
Go to
Section:
CHAPTER 3.1 - Carbon Compounds
Carbohydrates
Go to
Section:
Forms
SUCROSE
from
dehydration
synthesis
Hydrogen Bonding
In a hydrogen bond, an atom or molecule
interacts weakly with a hydrogen atom
already taking part in a polar covalent
bond
Hydrogen Bonds
Hydrogen bonds form any time a
hydrogen atom is bonded to an F, O, N
They are weak bonds between to
molecules
Hydrogen bonds make liquid water
cohesive
Properties of water
Water is polar
Hydrophilic; water
loving
Hydrophobic; water
hating
Cohesive properties
due to hydrogen
bonding
Universal solvent
Water’s hydrogen bonds moderate temp.
Heat
The amount of energy associated with the movement of
atoms and molecules in the body
Warming
Disrupts (H) bonds then speeds up molecules
Store large amounts of heat while warming a few degrees
Cooling
Heat energy is released when (H) bonds form, slowing
the cooling process
Water is the solvent of life
Solution: liquid consisting of a uniform
mixture of two or more substances
Solvent: dissolving agent
Solute: substance that is dissolved
Water as a Solvent
Cl-
Water
Cl-
Na+
Water
Na+
Section 2-2
Figure 2-9 NaCI Solution
Go to
Section:
NaCl as the solute
Acids, Bases and Salts
Acid is a proton donor (H+), have a pH
less than 7
Base is an proton acceptor; has a pH
greater than 7
A salt is formed when and acid reacts
with a base
Buffer is a solution that is resistance to
pH change
The pH scale
pH is a measure of the H+ concentration
in a solution
The greater the H+ the lower the pH