Biology 1132 Study Notes - Chapters 1, 4, 5, 6

Chapter 1: Environmental Interrelatedness

What is environmental science, per se, and what does it encompass
- Environmental science is the study of interactions among the biological, chemical, and physical components of the environment and the effects of human activities on these systems.
- It encompasses understanding how ecosystems function, how humans impact them, and how to sustain natural resources.
Interrelatedness is a key concept
- All components of the environment are connected; changes in one part affect others.
Ecosystem concept
- May have recognized boundaries
- May have indistinct boundaries
- Often has political subdivisions
Things an individual can do to protect the environment (10 things)
- Note: The transcript mentions 10 actions but does not enumerate them.
Sustainability
- Long-term maintenance of healthy ecosystems and resources for future generations.
Emerging global issues
- Population growth
- How to maintain a functional ecosystem
- Food security
- Environment and health
- i. Obesity
- ii. Water pollution
- iii. Air pollution
- iv. Traffic congestion
Security and the environment
- Environmental issues can influence and be influenced by security concerns (e.g., resource scarcity, conflict, health threats).
What was the Earth Summit (UNCED) in 1992
- United Nations Conference on Environment and Development (Earth Summit) held in Rio de Janeiro in 1992.
What was the Kyoto Protocol?
- International agreement linked to UNFCCC aimed at reducing greenhouse gas emissions.

Chapter 4: Scientific Concepts

Nature of Science
- Basic assumptions
- i. There are specific causes for events we see in the environment.
- ii. The causes can be identified.
- iii. There are general rules and patterns that may be used to describe what happens in nature.
- iv. An event that happens again and again probably has the same cause each time.
- v. What one person perceives can be perceived by others.
- vi. The same fundamental rules of nature apply regardless of when or where they occur.
Elements of the scientific method
- i. Careful observation
- ii. Asking questions about the observed event
- iii. Testing hypotheses
- Define hypothesis
- It must be testable or it is mere speculation
- An experiment is a recreation of an event or observation in order to support or reject a hypothesis (You don’t PROVE it)
- iv. There are multiple variables to account for
- v. What is a controlled experiment?
- vi. Is it reproducible?
- vii. Note the role of bias in an experiment
- viii. Submitting the ideas to the scrutiny of others
What is a theory? A law?
Cause and effect relationships
- a. An example is the correlation between cooler weather and falling leaves
- b. Actually the shortening of days affects the internal clock of plants, not the cooler weather
Limitations of science
- a. Not useful for religious studies or the supernatural
- b. How is beauty assessed—this is subjective, not empirical, so not science
Pseudoscience
- a. Quackery
- b. Often uses claims that sound scientific but aren’t
- c. Phrases like “Proven by science” and “The debate is over” are hallmarks of pseudoscience and are salesmanship
Matter
- a. Atomic number
- b. Atomic mass
- c. Parts of an atom
- i. Proton (+)
- ii. Neutron (neutral)
- iii. Electron (-)
- iv. Isotopes
- v. Electrons fill shells around the nucleus
- d. Molecules, mixtures, compounds
- e. ext{pH} = -oxed{ ext{log}}[H^+]
Bonds
- a. Ionic: transfer of electrons
- b. Covalent: sharing electrons
- c. Hydrogen bonds: molecular interactions typical of electronegative oxygen and electropositive hydrogens; unequal electron distribution
- i. Water molecules are polar and not symmetrical
Chemical reactions
- a. Endothermic: new bonds formed have more chemical energy and require heat
- b. Exothermic: new bonds formed have less chemical energy and release heat
- c. $ext{CH}4 + 2 ext{O}2 ightarrow ext{CO}2 + 2 ext{H}2 ext{O} + ext{heat} + ext{light}$
Energy
- a. Catalysts: make products form more quickly but only make a reaction occur in the direction it was already headed
- i. Lower activation energy
- ii. Aren’t used up in the reaction
- b. Enzymes are proteins and are biological catalysts
- i. Have a narrow pH range
- ii. Have a narrow temperature range
- iii. Only work on one substrate
- iv. Photosynthesis is a prime example
- c. Kinetic energy — energy of motion
- d. Potential energy — stored energy (often due to height or position)
- e. States of matter
- i. Solid, liquid, gas
- ii. Sensible heat vs. latent heat
Laws of thermodynamics
- i. First law: energy neither created nor destroyed— it merely changes form
- ii. Second law: whenever energy is converted from one form to another, some useful energy is lost (usually as heat) as things become more disordered; useful energy is not the same as total energy
Energy flow and how it affects the environment
- a. Entropy
- b. The process of becoming disordered is correlated with the constant flow towards a more dilute form of heat
- c. It takes work to maintain something and get it more ordered
- d. Energy quality
- i. Compare and contrast high and low quality heat
- e. Biological systems
- i. These are open systems and heat is released to the environment
- f. Pollution
- i. Heat is a pollutant
- ii. A lot of energy is not high quality
- iii. Total energy in the universe is a constant

Chapter 5: Interactions, Environments, and Organisms

Concepts in ecology
- a. Biotic factors (know examples)
- b. Abiotic factors (know examples)
Limiting factors
- a. Definition: shortage or absence restricts the species
- b. Range of tolerance
Habitat and niche
- a. Habitat: place
- b. Niche: functional role
Natural selection
- a. Genes determine variation
- b. More offspring produced than can survive
- c. Less resources to support more individuals
- d. Variation makes some individuals better at obtaining resources
How does speciation occur? Extinction?
Coevolution
Role of natural selection
- a. Genes—determine characteristics
- b. Population—organisms of a specific kind in a defined geographic region
Organisms and interactions
- a. Predation
- b. Competition
- c. Symbiosis
- d. Parasitism
- e. Commensalism
- f. Mutualism
What is a community?
Roles of species
- a. Producers
- b. Consumers
- i. Primary
- ii. Secondary
- iii. Tertiary
Keystone species
Energy flow through ecosystems
- a. Trophic levels
- b. Biomass: weight of living material in a trophic level
Food chains and food webs
- a. See figure 5.27 — trophic levels in a food chain
Nutrient cycles / biogeochemical cycles
- a. Carbon cycle
- b. Nitrogen cycle
- c. Phosphorus cycle

Chapter 6: Ecosystems and Communities

Succession
Climax community
Primary succession
Secondary succession
Biomes are determined by climate
- a. Precipitation
- b. Temperature
Major terrestrial biomes — know rainfall and organisms
- a. Desert
- b. Temperate grassland
- c. Savanna
- d. Mediterranean shrubland (chaparral)
- e. Temperate deciduous forest
- f. Tropical dry forest
- g. Tropical rain forest
- h. Taiga / northern coniferous forest
- i. Tundra
Major aquatic ecosystems
- a. MARINE (know examples)
- i. Pelagic
- ii. Benthic
- iii. Coral reef
- iv. The abyss
- v. Mangrove swamps
- vi. Estuaries
- b. FRESHWATER
- i. Lakes
- ii. Ponds
- iii. Streams and rivers