Chap 1.docx

Chapter 1 ========= EVOLUTION, THEMES OF BIOLOGY, AND SCIENTIFIC INQUIRY ==================================================== **Properties of Life** About **8.7 million species** are believed to be living on Earth today!! **WITH SO MANY DIFFERENT SPECIES THERE ARE MANY PROPERTIES THEY HAVE IN CO...

Chapter 1 ========= EVOLUTION, THEMES OF BIOLOGY, AND SCIENTIFIC INQUIRY ==================================================== **Properties of Life** About **8.7 million species** are believed to be living on Earth today!! **WITH SO MANY DIFFERENT SPECIES THERE ARE MANY PROPERTIES THEY HAVE IN COMMON (see fig 1.2).** **1\-\-- Evolutionary Adaptation.** **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.** **Conclusion: More "good" genes survive and therefore the population changes genetically. That's Evolution!** **2 \-\--** Life contains an **order** of structural levels with each level building on the levels beneath it. \>\>\>\>\> Hierarchy of biological organization (see fig 1.3) **(*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) **-Organisms** **-Populations** **-Communities** **-Ecosystem**s **-**Planet (**Biosphere**) **3 \-\--** Each level of biological organization has **emergent properties**. (See fig 2.2). \-\--**emergent property**. **4 \-\--** Structure and function are related. Cells are the basic unit of structure and function. \-\--**prokaryotic cells**(see fig 1.4). \-\--**eukaryotic cells**(see fig 1.4) **5 \-\--** Genetic information is expressed and transmitted. DNA is the basis of heritable information (see fig 1.6). DNA provides the instructional methods that guide the **growth and development** of multicellular organism. 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**. **6 \-\--** Life has the ability to acquire material and **energy** **Energy**-Capacity to do work All levels of biological organization are thermodynamically "open systems" (see fig 1.9). **7 \-\--** Organisms have the ability to maintain their structure and regulate their internal environment. Negative feedback (see fig 1.10) and positive feedback are the 2 common mechanism used for regulation. This ability to maintain structure and regulate is called **homeostasis**. \-\--**homeostasis** **8 \-\-- Organisms interact with other organisms and with their environment. These interactions form the basis of ecosystems.** Evolution produces unity and diversity. **With all the underlying similarities there is an amazing diversity of the organisms on the planet.** **HOW IS THE DIVERSITY OF LIFE ARRANGED** **Premise: The division of living organisms into groups makes the study of them easier and more logical.** **\>\>\>\>\>The three-domain system, was conceived about 4 decades ago (see fig 1.13).** **In this system commonalities in the DNA organization and other characteristics allows groups, termed domains, to be constructed There are two prokaryotic domains, Bacteria and Archaea, and a eukaryotic domain; Eukarya** **In domain Eukarya there are currently four subdivisions known as kingdoms: Protista, Plantae, Fungi, and Animalia.** **Science is an activity that often involves one of 2 methods:** **Discovery science focused on the Where, What, and When** **and** **Hypothesis based science focused on the How and Why** Both methods involve science as an activity. The process of science involves observation and analysis of data. **Quantitative data and qualitative data** Both methods also follow certain principles 1. all events have a natural cause - **natural causality** **Hypothesis based science uses a HYPOTHETICO-DEDUCTIVE process and deductive reasoning** This type of process is sometime referred to as "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. A **theory** is an explanation of natural events that is based on a LARGE number of observations and/or experiments.