AP biology: AP Test

biology review

science

  • the heart of science is inquiry- search for information and an explanation with making observations and forming hypotheses

making observations

  • making observations- describes natural structures of processes through observation and analysis of data

  • data- recorded observations

  • qualitative- observations with senses

  • quantitative- measured using instruments

  • inductive reasoning- derive generalizations based on a large number of specific observations

forming hypotheses

  • hypothesis- predictions that can be tested by recording more observations or experiments

  • include “if…then…(because…)”

  • NEVER SAY- “the hypothesis is correct because…”

  • deductive reasoning- specific results are deriverde from general premises

hypotheses

  1. start with a null hypothetsis (the researcher attempts to disprove, reject, or nullify your hypothesis)

  2. list the alternative hypothesis

hypothesis/theory/law

  • hypothesis- an explanation to a question (can be tested by an experiment or an observation but can also be rejected)

  • theory- summarizes a group of hypotheses (new hypotheses can be generated and also NEVER becomes a law)

  • scientific law- statement of fact usually as a mathematical formula (like newtons law of gravity)

experiments

  • start with an observation and a hypothsis

  • use control groups (+ and/or -) and experimental groups

  • use an independent variable and a dependent variable

  • use constants

  • minimum of three trials

variables vs constants

  • a variable is something that is changed in the experiment

  • a consant is something that does not change throughout

  • independent variable- the one factor that is changed by the person doing the experiments (represents a quantity that is being manipulated in an experiment)

  • dependent variable- the factor which is measured in the experiement (represents a quantity whose value depends on how the independent variable is manipulated)

control groups

  • control are essential elements of an experiment

  • they help eliminate experimental errors and biases of researchers

  • results of the control experiments validate statistical analysis of the experiment

  • reliability of the experiment increases

  • controls are NOT constants

- there are two types of controls: positive and negative

  • positive: group not exposed to the experimental treatment or independent variable (but it is exposed to a treatment known to produce the expected effect)

  • negative: group not exposed to ANY treatment or exposed to a treatment that is known to have NO effect (ensure that there is no effect when there should be no effect)

    unit one: chemistry of life

    REVIEW:

  • matter- anything that takes up space and has mass

  • element- a substance that cannot be broken down into other substances by chemical reactions

  • compound- a substance consisting of two or more different elements combined in a fixed ratio

  • essential elements- of the 92 naturally occuring elements 20-25% are essential to survive and reproduce. CHOPN make up 96% of living matter

  • trace elements- of the 92 naturally occuring elements, these are required by an organism in very small quantities.

Chemistry review

  • lewis dot model- simplified Bohr diagrams

types of bonds

  • elements want to be stable (they achieve this by forming chemical bonds with other elements)

  • octet rule- elements will gain, lose, or share electrons to complete their valence shell and become stable (like noble gases)

  • chemical bonds- an attraction between 2 atoms, resulting from the sharing or transferring of valence electrons

  • electronegativity- the measure of an atom’s ability to attract electrons to itself

  • covalent bonds- when two or more atoms share electrons

  • forms molecules and compounds

    • single bond: 1 pair of shared electrons

    • double bond: 2 pairs of shared electrons

    • triple bond: 3 pairs of shared electrons

  • nonpolar convalent bonds: electrons are shared equally between two atoms

  • polar covalent bonds: electrons are not shared equally between two atoms