1. Organization of living systems begins with cells; cells are made of molecules that contain atoms.

2. Cells combine to form a tissue (e.g., nervous tissue).

3. Different tissues combine to make up organs (e.g., the brain).

4. Organs work together as organ systems (e.g., the brain, spinal cord, etc.)

5. Multicellular organisms may have many organ systems.

6. A species in a particular area (e.g., gray squirrels in a forest) constitutes a population.

7. Different populations inhabiting an area at the same time make up a community. (Fig. 1.1)

8. A community and its physical environment constitutes an ecosystem.

9. Each level of organization has emergent properties not accounted for by a sum of the parts.

1. Maintaining organization and carrying on life requires outside source of energy. (Fig. 1.2)

2. Food provides nutrient molecules used as building blocks or for energy.

3. Energy is capacity to do work; it takes work to maintain organization of the cell and organism.

4. Metabolism is all chemical reactions that occur in a cell.

5. Ultimate source of energy for life on earth is the sun through photosynthesis.

6. Organisms must remain homeostatic or keep themselves stable in temperature, moisture level, acidity, and other physiological factors.

1. Response often results in movements of plant or animal.

2. Ability to respond helps organism survive.

3. Responses to environment altogether constitute behavior of organism.

1. Reproduction is the ability of an organism to make a copy of itself.

2. Bacteria, protozoa, etc. simply split into two.

3. Multicellular organisms may pair sperm with egg; resulting in an immature individual, which develops to become the adult.

4. Organisms develop as result of blueprint of instructions encoded in their genes.

5. Genes are made of long molecules of DNA that specify how the organism is ordered.

1. Adaptations are modifications that make an organism suited to its way of life. (Fig. 1.3)

2. Natural selection is process by which species becomes modified over time.

3. Descent with modification

1. Populations within a community interact among themselves and with the physical and chemical environment, forming an ecosystem.

2. All ecosystems together make up the biosphere, the thin layer of life that encircles the earth.

3. Interactions between populations in an ecosystem tend to keep the system relatively stable.

4. Food relationships form a major part of interaction between populations. (Fig. 1.4)

5. Large ecosystem keeps cycling its raw materials (e.g., water and nitrogen).

6. A constant supply of solar energy is required for an ecosystem and for life to exist.

1. Found in clear, shallow tropical waters; has highest abundance of living things.

2. Reef base is non-living stony coral where crevices provide shelter; outer layers are living tissues.

1. Most complex ecosystems in the world; found at low altitudes near equator.

2. Require plentiful sun and rainfall all year long.

3. Broadleaf evergreen canopy intercepts most sunlight; understory layer consists of shrubs, ferns, etc.

4. Most organisms live in canopy; includes tree sloths, monkeys, birds, butterflies, bats, etc.

1. Human populations tend to modify existing ecosystems for own purposes.

2. Fewer ecosystems are able to function adequately to sustain human populations.

3. Preservation of biodiversity is extremely important.

1. Taxonomy is the biological discipline of identifying and classifying organisms.

1. Scientific name is a binomial.

2. System was started by Swedish naturalist Carolus Linnaeus.

3. Scientific name of a species---underlined or in italics---contains two parts:
first name is genus; second name is specific epithet of organism.

1. Classification uses groups: species, genus, family, order, class, phylum/division, and kingdom.

1. Living things on this planet are categorized into five kingdoms: (Fig. 1.7)

2. Monera---prokaryotic, unicellular organisms (archaebacteria and eubacteria);

3. Protista---eukaryotic, unicellular, colonial and simple multicellular organisms (protozoa, etc.);

4. Fungi---eukaryotic, mostly multicellular, filamentous organisms that absorb their nutrients;

5. Plantae---eukaryotic, multicellular, and photosynthetic organisms (plants);

6. Animalia---eukaryotic, multicellular organisms (animals) that ingest their nutrients.

1. Scientific investigation is limited to questions that can be studied objectively.

2. Scientific conclusions are subject to change when new techniques and equipment are available.

3. Ultimate goal of science is to understand natural world in terms of theories; examples include Cell Theory, Biogenesis Theory, Theory of Evolution and Gene Theory.

1. Scientific method is an approach employed by biologists for gathering information. (Fig. 1.8) [transp. 1]

2. Based on observations, or data in the scientific literature, scientists formulate a hypothesis.

3. Formulating a hypothesis involves inductive reasoning; (i.e., isolated facts are used to generalize about an observed phenomenon).

4. It is possible to prove a hypothesis false, but it cannot be proven true.

5. An experiment in industrial melanism---a case study in the scientific method.

6. Some investigations are controlled experiments.

7. Some investigations are observational---ostrich egg case study is example.