Biology 10, Las Positas College
Introduction, Scientific Method
Chapter 1

I-Scientific Method

A-Scientific Theory
B-Control Group

II-Grouping Life’s Diverse Forms

A-Unity
B-Diversity
C-Levels of Organization

III-Interdependencies among Organisms

IV-Binomial Nomenclature

 

I-Scientific Method

Observation
Develop hypothesis. Form = If . . , then . . .
Prediction
Test hypothesis
Make conclusion
B-Scientific Theory

Definition: Scientific theory – a synthesis of hypotheses; a powerful concept that helps scientists make predictions about the world
Law: a statement of absolute and universal truth

II- Grouping Life’s Diverse Forms


A. Unity

1. Requirements for Life

a. energy
b. water
c. nutrients
d. temperature suitable for life

Abundance of life depends upon abundance of above 4 requirements

2. Properties which distinguish life from non-life

a. internal environment different from outside
b. growth & development
c. take in energy &use it for life activities
d. respond to environment
e. DNA -> precise reproduction

3.Common characteristics of all living things

a. all made of lifeless atoms, organized into living organism – most common chemicals = carbon = C, nitrogen = N, hydrogen = H, oxygen = O
b. interact with other living things
c. reproduce via DNA

B-Diversity
5-30,000,000 species, fraction described, many different creature and plants but have enough similarities to form 3 domains

3 Domains

1. Eubacteria – prokaryotes = no internal membranes

2. Archea – prokaryotes

No internal membranes.
Live in extreme environments
3. Eukarya – have internal membranes, much larger, complex, than prokaryotes
4 kingdoms

1. Protista – mostly single celled creatures. Have internal organelles and nucleus therefore can be much larger and more complex than bacteria.

Remaining 3 kingdoms also have membrane-bound internal organelles and nucleus, are multicellular, more complex, usually larger than Protista.

2. Plants – photosynthesis -> self feeding and feed animals and fungi, multicelled, cell walls. Get energy from SUN.
3. Animals – move, eat others, consumers = obtain food by eating and digesting other organisms. Include plant eaters, parasites and meat eaters. Usually move during at least some stage of their life.
4. Fungus- decomposers. Secrete substances that digest food outside of body, then their cells absorb the digested molecules.

C. Levels of Organization

Living organisms are made up of chemicals organized into cells which are organized into plants or animals which interact among themselves and the rest of the biosphere.

Subatomic particle -> atoms -> molecules -> cells -> tissues -> organs -> organ systems -> organism -> populations -> communities -> biosphere

III-Interdependencies Among Organisms

Producers (plants, algae, photosynthetic bacteria) capture sun’s energy. Use or store energy.
Consumers, decomposers use energy stored by producers.
Nutrients recycled.
Energy is one-way flow because so much energy is lost to heat and metabolism at each transfer.


IV-Binomial Nomenclature

Each kind of organism has a scientific name consisting of a Genus and Species name.

Genus-always italicized or underlined and capitalized
Species-always underlined or italicized and never capitalized