NOTES FOR BIOLOGY 1201

Section 001

Spring 2005

DR. STEVEN POMARICO

Properties of Life - 1.1.1

About 1.5 million species have been identified and named!!

WITH SO MANY DIFFERENT SPECIES THERE ARE MANY UNIFYING SIMILARITIES.

1---Life contains an order of structural levels with each level building on the levels beneath it.

>>>>> Hierarchy of biological organization (the definitions for these are handled separately, here you should concentrate on the organization)

-Atoms

-Molecules

-Macromolecules

-Organelles (not present in prokaryotes)

-Cells

-Tissues (not present in prokaryotes or all eukaryotes)

-Organs (not present in prokaryotes or all eukaryotes)

-Organ systems (not present in prokaryotes or all eukaryotes)

-Organisms

-Populations

-Community

-Ecosystem

-Biomes

-Planet (Biosphere)

Each level of biological organization has emergent properties.

---emergent property.

3---Living things reproduce and cells are the basic unit of structure and function.

---prokaryotic cells

---eukaryotic cells

-DNA is the basis of heritable information

 The passing of DNA from one generation to another is the basis of inheritance.

Inheritance-Acquisition of traits by transmission of DNA from parent to offspring.

This process of transmitting the DNA to new generations is built into the functions of reproduction.

4--DNA also provides the instructional methods that guide the growth and development of multicellular organism. .

5---Life has the ability to acquire material and energy

                             >The material and energy are often transformed<

         Energy-Capacity to do work

All levels of biological organization are thermodynamically “open systems”.

6----Organisms have the ability to maintain their structure and regulate their internal environment.

---homeostasis

Structure and function are related.

The Nature of Science: The Story of Darwin - 1.2.2

Science is an activity that often involves HYPOTHETICO-DEDUCTIVE processes

Science as an activity is a process of discovery

                     The principles behind this discovery process are:

                                1) all events have a natural cause - natural causality

                                2) natural causes obey natural laws

                                3) natural laws don=t change with time or distance

The process of scientific discovery usually proceeds by the scientific method

          Make observations - Lights don’t go on when you flip the light switch.

          Form a hypothesis - Bulb is burned out.

          Conduct experiments - Change the bulb. 

          Make conclusions - do the results of the experiments support your hypothesis

                                                     If not then you have to change your hypothesis

                                                     If they do then your one step closer to a theory

A theory is an explanation of natural events that is based on a LARGE number of observations and/or experiments.

The theory of evolution is a central theme in biology.

The ability to evolve is built into organisms.

          -organisms within a species are variable (e.g., some are tall some are short)

          -variability means some are “better” suited to survival.

          -variability comes from the genes and genes are inherited.

Conclusion: More “good” genes survive and therefore the population changes.