Download Biology Test I

Chris Khan 2005
Beginnings of Biology
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Biology is the study of life
The Scientific Method is an orderly and systematic way for problem solving
There are 7 steps in the Scientific Method: Make Observations, Form Hypothesis, Make Prediction, Perform Experiment,
Analyze Experiment Data, Draw a Conclusion, and Report your Results.
A good experiment needs an independent variable, a dependent variable, a control experiment, a constant, and repeated trials.
Homologous: structures with a common evolutionary ancestor.
Analogous: structures that are similar in function, but not in evolutionary structure or ancestor.
Wallace wrote a letter to Darwin asking for help in science on his believed theory of evolution. It turns out that Wallus and
Darwin had nearly identical papers on evolution and both got equal credit for it.
Evolution: Evidence for Evolution:
o Fossil Record
 Homologous
 Analogous
o Geographic Distribution
o Comparative Biochemistry
o Comparative embryology
Humans are clearly related to chimpanzees with about 95% of the same genes.
Lamarck and Darwin were closely associated with evolution.
Theories of Evolution
o Jean-Baptiste Lamarck
 1809
 Use and Disuse (Develop with Use)
 Inheritance of Acquired Characteristics (FALSE)
 Characteristics developed in response to need
 Disproved by Weismann (tried to see If offspring would have a smaller tail if tail of parent mouse was cut
off)
Somatic Cells: any body cell not involved in reproduction
Germ Cell: any cell used for reproduction
Charles Darwin
o 1858
o Natural Selection
o Over-Production
o Struggle for Existence
o Variation
o Survival of the Fittest
o Origin of New Species by the inheritance of successful variations
o Lived in Kent
o Got Shaggus disease from the kissing bug (reduva bug)
o Turtle Shells looked different based on what they ate
Alfred Russell Wallace
o Presented the same idea in a letter to Darwin
Ameba reproduce by binary fission and dividing in two
Carrying Capacity: top number on a chart
In survival, the winner is the one who can survive in it’s habitat
Darwin’s body is buried in the West minister Abbott
A Cell is the basic unit of a living thing
Organelles are parts of a cell
Smaller than organelles are molecules, atoms, and sub-atomic particles…
Cells make up tissues, which make up organs, organ systems, organisms, species, population, community, ecosystem, biome,
and biospheres.
An atom is the smallest part of an element that can be used in a chemical reaction.
Mendalaya made the Periodic Table.
Atoms look like a solar system.
Ions are atoms without electrons.
Figure I:
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Half-Life: the time it takes for an element to lose half of it’s mass.
The Geiger counter is a way to find out how radioactive an item is.
DNA changes, chemicals, radiation, etc. cause mutations.
HCl: Hydrochloric Acid
H2O2: Hydrogen Peroxide
C6H12O6: Glucose
Valence: electrons in the highest energy level.
Atomic Number: the number of protons in a nucleus that determines which substance we are working with
Atomic Mass: the sum of the neutrons and protons in an atom
Compound: substance composed of 2 or more elements chemically combined in definite proportions by weight
Covalent Bond: bond formed between two atoms by the sharing of electrons
Electro negativity: the power of an atom in a molecule to attract electrons to itself
Element: substance which cannot be broken down into simpler substances by ordinary chemical means
Empirical Formula: simplest formula of a compound; lowest whole number ratio of atoms in a substance
Hydrogen Bond: bond between 2 polar molecules; between the H atom in one molecule and an atom of high electro
negativity in another
Ion: a charged atom
Ionic Bond: bond between ions resulting from the loss and gain of electrons
Isomers: compounds with the same molecular formula but different structural formulas
Isotope: atoms with the same atomic number but different atomic masses (example: Carbon 14, when carbon’s atomic mass
is 12)
Lewis Structure: structure showing covalent bonds and valence electrons in a molecule
Molecule: the smallest part of a substance having all the properties of the substance
Molecular Formula: formula which denotes the composition of a molecule and the exact number of atoms that are present
Non Polar Molecule: a covalently bonded molecule which does not have a positive and negative end
Polar Molecule: molecules with a positive and negative end, due to the unequal sharing of a pair of electrons
Structural Formula: formula which uses dashes to show covalent bonds between atoms
Valence: combining power of an element (electrons that can be borrowed, loaned, or shared) (number of electrons in the
highest energy level)
Quantum Mechanics Model of the Atom:
Principle Quantum tells the energy level of the electron (n)
Second Quantum tells the shape of the electron orbital cloud (l)
Third Quantum tells the orientation of the orbital (m)
Fourth Quantum tells the spin of the electron (s)
S Orbital—spherical shape (1)
P Orbital—dumbbell shape (3)
D Orbital—(5)
F Orbital—(7)
Temperature determines how fast an atom moves.
Carbon electrons are held more tightly because they have 6 protons.
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Column
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Bonds
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Shape
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Example
IA
1
Linear
H2
VIII A
1
Linear
F2
VI A
2
Bent
H2O
VA
3
Pyramid
NH3
IV A
4
Tetra-Hedron
CH4
If the difference in electro negativity is equal to, or greater, than 1.7, the bond is ionic. If the electro negativity is less than
1.7, the bond is covalent.
Molecular Formula: written as the formula of the atom (i.e. H2O)
Empirical Formula: molecular formula written in simplest form (i.e. H 2O2 = HO)
Structural Formula: uses dashes to show covalent bonds.
Lewis Structure: shows covalent bonds and valence electrons (dot method).
Hydrogen Gas: H2
Water: H2O
H:H is a covalent bond
CH4: Methane
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C2H6: Ethane
C3H8: Propane
C4H10: Butane
C5H12: Pentane
Polarity: H—H is nonpolar (because there is no dipole; there are 2 atoms of same electro negativity)
Dipole: positive and negative end
Molecules are Polar if their Lewis Structure is non-symmetrical. If the Lewis Structure is symmetrical, the molecule is nonpolar.
The part of the atom with higher electro negativity is the negative end and the part with lower electro negativity is the
negative end.
Solute dissolves in the solvent. More solvent is a dilute. More solute is concentrated.
PH (lower-case P and upper-case H) is measure of how acidic or basic a substance is. Scale goes from 0-14. 0-6 is acidic, 7
is neutral and 8-14 is basic.
Takes the hydrogen proton; leaving the electron with chlorine transforming NH 3 into NH4+ with a positive charge and making
Cl into Cl- with a negative charge.
RULE OF THUMB for solvents and solutes: “Like” dissolves “like”
PH: -log [H+]
Increase in PH is an increase of an exponent power of ten.
Water is a polar molecule with a bent shape.
Water exhibits hydrogen bonding when close to another water molecule.
Water has cohesion and sticks to itself.
Water does NOT dissolve non-polar molecules.
Hydrophobia: fear of water.
Water molecules dissolve polar molecules by bonding its negative end to the positive end.
Amphipathic molecules are part polar and part non-polar.
When water boils, bubbles of steam form.
Water is most dense at 4°C.
Solutions are made up of a solute and a solvent.
The solute is always the lesser amount and the solvent is the greater amount.
Water is a good solvent.
Molarity>> M= Moles of Solute
Liter of Solvent Solution
One “mole” is the number of 6.02(1023)
Molecules in living things include: H2O, CO2, C6H12O6 (glucose), NaCl, O2, HCl, S, Ca, K, etc…
Living things need protein, carbohydrates, lipids, and nucleic acids.
Protein is made up of C, H, O, N, and S (contains nitrogen)
Proteins are responsible for the structure of the body, proteins are found in cells, proteins repair body cells, proteins make up
hormones, proteins make up enzymes, and proteins make up anti-bodies
Enzymes are organic catalysts that break down food
All enzymes are catalysts, but not all catalysts are enzymes
Non-polar molecules float on water
Proteins can be gene protein, storage protein, structural protein, receptor protein, and defensive protein.
Proteins are the building blocks of life.
Organic Compounds contain carbon