Home
Announcements
Syllabus
Schedule
Lecture Notes
Lab WriteUp Sheets
Study Guides
Extra Credit
Field Trip Info
 
Up
Lecture 1
Lecture 1 Quiz
Lecture 2
Lecture 2 Quiz
Lecture 3
Lecture 3 Quiz
Lecture 4
Lecture 4 Quiz
Lecture 5
Lecture 5 Quiz
Lecture 6
Lecture 6 Quiz
Lecture 7
Lecture 7 Quiz
Lecture 8
Lecture 8 Quiz
Lecture 9
Lecture 9 Quiz
Lecture 10
Lecture 12
Lecture 13
Lecture 14
Review Game #3
 

LAMC
BIOLOGY

LAMC Bio 3 Lecture Notes: Chapter 1 – Introduction & Study of Life

Reading Assignment: Chapter 1

Learning Outcomes:
By the end of today’s lecture, you should be able to:
- Identify the different levels of biological organization
- List the properties of living organisms and determine whether something is living/non-living
- Explain the components and implications of the cell theory
- Explain the limitations of the fossil record
- Identify the steps used in the Scientific Method
- Explain the difference between inductive and deductive reasoning
- Apply the Scientific Method to answer a biological question

I. Hierarchy of Biological Organization
Atom à Molecule à Organelle à Cell à Tissue à Organ à Organ System à Organism à Population à Community à Ecosystem à Biosphere

II. Properties of Living Things:
1) Having an ordered structure
2) Reproduction
3) Growth and Development
4) Energy utilization
5) Response to the environment
6) Homeostasis
7) Evolutionary adaptation (of populations)

III. Cell Theory:

Robert Hooke (1665) – first described cells from a section of cork using a microscope that magnified 30x.

Anton van Leeuwenhoek – around the same time as R. Hooke, used a more developed magnifying glass to observe pond water, blood and sperm cells at a magnification of 300x.

Schleiden and Schwann (1839) – two scientists who reviewed the data collected by numerous people to conclude that all living things consist of cells.

The two components of the cell theory are:
1) All living things consist of cells
2) All cells come from other cells

The important implications of the cell theory are:
1) All individuals in a population of single-celled organisms are related by ancestry.
2) All cells in a multi-cellular organism are descended from the same ancestral cell.

IV. Spontaneous Generation Hypothesis:
This was the prevailing theory of how life arose before the origin of the cell theory.
It is the idea that living things can emerge from inanimate (non-living) material.
e.g. flies emerge from spoiled meat
Louis Pasteur’s experiment conclusively disproved this idea.

V. History of Life:

A. Limitations of the fossil record:

1) the structure of the organism is important – hard bodied organisms fossilize better than soft-bodied organisms.  Therefore the fossil record is highly biased in favor of organisms with a hard skeleton.

2) The environment that the organism dies in is important – warm, moist areas are highly conducive to decay by microorganisms, so there are fewer fossils in these regions.  Exposure to the elements after death also encourages decay and prevents fossilization.

3) Geological activity of the area containing fossils is important.  Many fossils are destroyed when earthquakes, volcanic eruptions, etc. disturb the region.  Consequently older fossils are rarer and are in poorer condition than more recent fossils.

4) In addition to all the limitations inherent in the formation and preservation of fossils, scientists need to ultimately be able to find the fossils.

VI. Scientific Method:

A. The following steps should be carried out when conducting scientific experiments:

1) Make observations
2) Formulate a question
3) Formulate a hypothesis
4) Design an experiment to test the hypothesis
5) Collect data and analyze results
6) Reach a conclusion – do the results support or refute the hypothesis?

An experiment can disprove a hypothesis, but it can’t prove it to be true; it can only support it.  If numerous experiments provide support for the same hypothesis, that hypothesis can become a “theory”.

B. Types of reasoning used in scientific experiments:

1) Deductive reasoning:
- go from general observations and known background information to make a specific prediction about the outcome of an event or the answer to a question

2) Inductive reasoning:
- this type of reasoning is based on specific experimental results; this is the only way in which new knowledge is attained

©2003-2004 Dilek Sanver-Wang, MS
Los Angeles, CA USA.  All Rights Reserved.