ISSUES IN BIOLOGY & THE SCIENTIFIC METHODPacket #1Chapter #1AP Biology

BIOTERRORISM

BIOTERRORISM Bioterrorism

The use of biochemical agents for terrorist purposes.

Biowarfare Use of disease-producing microorganisms or

biocides to cause death or injury to humans, animals and/or plants

Biochemical Agents Pathogens

Anthrax Bacillus anthracis

Smallpox Variola major

Agriculture pesticides

AVIAN FLU PANDEMIC

AVIAN FLU PANDEMIC Refers to influenza A viruses found chiefly in

birds Some infections, caused by the virus, can be

carried over to the human population Hong Kong 1997 Virginia 2002 New York 2003 Vietnam 2005 Iraq 2006 http://www.cdc.gov/flu/avian/gen-info/avian-flu-humans

.htm

EMBRYONIC STEM CELLS Ability to develop in

different cell types Treat diseases,

conditions and disabilities

http://stemcells.nih.gov/index.asp

OVER POPULATION Condition of any

organism’s numbers exceeding the carrying capacity of its ecological niche.

How does this relate to humans?

http://www.answers.com/over%20population

EMERGENT DISEASES http://www.cdc.gov/ncidod/id_links.htm

GLOBAL WARMING Increase in earth’s

average temperature and the climatic impacts that it may have.

BIODIVERSITY Biodiversity

– The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems.

A goal of scientists is to discover the effects of the previously mentioned not only on humans, but the estimated 7 – 20 million species on earth.

How do we do that?

SCIENTIFIC METHOD Manner for investigating nature

Scientists attempt to construct an accurate, reliable, consistent and non-biased representation of the natural world

Few scientists adhere to the “strict procedures” Creativity, individuality, distinct

SCIENTIFIC METHOD Scientific Theories

2 components Describes the patterns seen in the natural world Identifies a process or mechanism responsible for a

pattern Biology

A study of patterns of living things and their processes

SCIENTIFIC METHODCOMMON STEPS Observation

An observation is made regarding some event or characteristic of the world

A problem is developed An open-ended question that cannot be answered by a

yes or no answer

SCIENTIFIC METHODCOMMON STEPS Forming a Hypothesis

Postulating a premise An explanation of the phenomena observed Predict the existence of other phenomena or predict

quantitatively the results of new observations States results that may be expected from

observations and/or from experimental tests Can be based on one’s experience creativity or a sense

of what is practical Involves critical thinking and critical analysis

Deductive reasoning Reasoning from a general observation to a specific

conclusion Inductive reasoning

Reasoning from a specific case to the general Hypothetico Reasoning

Hypothesis developed Prediction deduced Tested against empirically derived data

SCIENTIFIC METHODCOMMON STEPS Experiment & Experimental Design

Unbiased Disprove a hypothesis

Evaluate an alternate hypothesis Null hypothesis

College/University Testing the hypothesis

Determining whether prediction is correct

SCIENTIFIC METHODCOMMON STEPS Experiment & Experimental Design

Methods and Procedures Adaptable

Able to reexamine as new information is collected Suppose to test a premise Best when designed to “disprove” a hypothesis

Often said in science that theories can never be proved but only disproved

A hypothesis can never be proven but evidence, collected during experimentation, can be used to support

EXPERIMENT III Experiment & Experimental Design

Variables must be defined Dependent Variables

Measureable and observable things Independent variable

Should be only one during an experiment Can be manipulated and changed

Controlled variables Kept constant and not allowed to change

*Control All experiments should have one Used as standard f comparison

SCIENTIFIC METHODCOMMON STEPS Collection of Results & Interpretation of Data

Must use same criteria (technique) for collecting all data

Representation of Data Tables Graphs

Interpretation of Data/Statistical Analysis T-test

Compares the means of two groups ANOVA

Compares the means of three or more groups Chi Square

Compares how closely the observed data is to the expected results

*Experimenters should also look at the variance

ANOVA

SCIENTIFIC METHODCOMMON STEPS Conclusion

Does the experiment match your predictions? Is your hypothesis supported Does your results agree with other findings?

Replicate the experiment

SCIENTIFIC METHOD

Scientific Law Hypothesis whose predictions have stood up

to thorough and rigorous testing with experiments and observations.

LIMITATIONS OF THE SCIENTIFIC METHOD Some hypotheses are not experimental

Intelligent beings in the universe Global warming *Theory of evolution