AP Bio Notes 

Cline: full division of organisms no longer able to reproduce with one another (speciation division due to distance)

Corn: provides 8 essential peptides

The Nature of Science: 1. seeks to explain the natural world 2. relies on evidence from the natural world to support evidence

Theory: well-supported explanation based upon OBSERVATION and EXPERIMENTATION

Elements of Theory: 1. explain known phenomena 2. predict new events 3. Theories can only be DISPROVED; it is modified when it no longer supports known phenomena

Evolution: A genetic change in a population over time; sometimes leads to the production of new species

Population: A group of organisms of the same species

Species: A group of organisms that are capable of INTERBREEDING

Fitness: how to measure capability of survival and reproduction

Gradualism: incremental changes that accumulate over time

Punctuated equilibrium: rapid spurts of genetic change due to rapid environmental changes

Genetic Drift: change in allelic frequency within a population due to MUTATION

Gene Flow: change in allelic frequency within a population due to MIGRATION

Why couldn’t Hybrid Orioles Survive?

• both types of orioles had different molting times
• the hybrids ended up molting twice
  • They couldn’t fly and escape predation
  • became weaker and ended up dying

Pinnate: Leaves where the veins come off of main vein

Palmate: Leaves with veins that come off of the stem

Simple Leaves: have a bud between stem and branch

Compound Leaves: Have a leaf with leaflets

Allopatric Speciation: Two populations of same species are living in DIFFERENT ENVIRONMENTS

• no gene flow between populations
• different adaptations to environments

Sympatric Speciation: two populations living in the SAME ENVIRONMENT

• one species in one are splits
  • becomes two separate species
  • pre-zygotic and post-zygotic barriers
  • prevent gene flow
  • ex) mating at different times of the day

Natural Selection: favorable traits that are heritable become MORE COMMON

• unfavorable traits become LESS COMMON

4 Elements of Evolution

1. variation
2. inheritance
3. selection
4. time

Variation: not all individuals are identical in a population

Causes of Variation:

• mutations: random changes in DNA
• sexual reproduction: Existing DNA is rearranged
• migration: New genes enter or leave a population

Inheritance: traits can be passed down from parent to offspring

Selection: Individuals best suited for their environment will survive and reproduce more

• those traits will become increasingly more common in the population
• those less suited are less likely to survive and reproduce

Time:

Punctuated Equilibrium: rapid spurts of genetic change due to rapid change in environment

Speciation: a possible result of evolution

Antibiotics: drugs that abolish the growth of micro-organisms

Micro-organisms: bacteria fungi, or protozoans

Misuses or Antibiotics:

• incomplete treatment
• over-prescribing
• overuse

phenomenon: direct observation of something (a fact observed)

data: facts and observations gathered and recorded about a problem

experiment: an organized, purposeful test in which certain conditions are changed

variables: the conditions in an experiment that are changed

Controlled experiment: only ONE VARIABLE is allowed to change (experimental observation); other factors are held constant

Experimental variable: what is changed in an experiment

Hypothesis: a possible explanation of phenomena

• a solution to a problem
• based on OBSERVATIONS MADE and FACTS GATHERED
• hypothesis must be TESTABLE and FALSIFIABLE
• often written using “if… then” statement

Theory: a logical explanation of a natural event

• based on results of EXPERIMENTATION and OBSERVATION

A theory must:

• explain known phenomena
• predict new events

Law: a statement that describes natural phenomena; a principle

Scientific Method: a logical method that utilizes a series of steps to investigate a problem or phenomenon

1. observations: made of a particular problem, or natural phenomenon
   • known facts are gathered
2. Data: gathered and may lead to a solution
   • observations and known facts
3. Hypothesis: formed as a possible explanation of the phenomenon
   • a solution to a problem, based upon observations made
4. Controlled Experiment: developed and performed to test a hypothesis
   • one variable is changed
   • the rest are held constant
   • experimental variable
5. Conclusions: made concerning the problem, and the accuracy of the hypothesis, based on result of experiment
6. Theory: may be formulated over time as a logical explanation of the observed phenomena
   • theories must be tested repeatedly
   • theories contradicted by experimentation must be changed or rejected

Scientific Method Order: Observations, data, hypothesis, controlled experiment, conclusions, theories

Scientific theories MUST:

• explain known phenomena
• predict new events
• (not an opinion)
• based on results of many experiment conducted by different scientists around the world

Biology: the study of life and living things

Characteristics of Organisms

1. use energy for life processes
2. made up of one or more cells
3. typically have a definite form and limited size
4. limited life span
5. responds to changes in their environment
6. are able to reproduce and they grow
7. carry out life processes in order to create stable internal environment (promotes homeostasis)

Life Processes:

• organisms take in materials from their external environment and change them into forms useful to life: nutrition
  • Nutrients- substances organisms need to live
  • Indigestion-- taking in food from the environment
  • digestion- the breakdown of complex food materials into simpler forms

Transport- the movement of materials into and out of cells

• circulatory system

Respiration- releases chemical energy from nutrients

Synthesis- organisms combine simple substances to form more complex substances, break down complex substances, release energy, by series of chemical reactions

Cellular respiration- way to get energy (mitochondria)

Earth’s Formation:

• core melted- tremendous pressure; energy from radioactive decay
• formed as a rocky sterile ball
• VIOLENT VOLCANISM led to formation of an ATMOSPHERE
• CONDENSATION of water vapor formed seas
• ORGANIC MOLECULES were synthesized from atmospheric gases (violent electrical storms; lightning)

4 billion years ago, the first living things appeared in oceans

• water protected life from UV radiation

• photosynthesis by early organism contributed O2 to Atmosphere

  • O2 fused together to form:
  • ozone layer: formed in upper atmosphere, blocking out most UV radiation (deadly to early life)
    • UV radiation causes damage to DNA

• Earth’s crust floats on semi-fluid mantle

  • mantle currents are formed by heating and cooling of flowing mantle material

• Convection current: circulation caused when heated, less dense material rises and is displaced by cooler, denser material

• mantle material is heated by the core

• material rises to crust and expands to sides

• it cools and sinks to interior

• mantle material pushing up from the core forms ridges

  1. deflected mantle spreading side to side carries the oceanic crust with it
  2. sea floor spreads

• expanding oceanic crust collides with the continental crust

  1. oceanic crust, being more dense, dives below continental crust
  2. Tremendous heat and pressure from the diving (subducting) crust causes rear continental margins
  3. where oceanic crust doesn’t subduct it pushes continental crust: causing continental drift

Levels of Organization:

• atoms- the smallest particle of an element that has the chemical properties of the element; all matter composed of atoms
• molecules- the smallest chemical unit of a compound that is capable of a stable, independent existence
• cells- the most basic unit of structure and function in living things
  • the smallest units of living things that show the characteristics of life
• tissues- a group of similar cells organized into a singular functioning unit
• organ- agroup of tissues that work together to perform a function
• organism- a living thing
• population- a group of organisms capable of inter-breeding (living together at the same time and place)
• community- the assemblage of different population living together in a defined area
• ecosystem- the organisms of a particular habitat together with the physical environment in which they live

Convergent Evolution- the process whereby organisms not closely related independently evolve similar traits

• same niche, different environment

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