Chapter One: Themes in the Study of Biology

Questions:

1. What are the properties common to all organisms?
2. What separates Domain Bacteria from Domain Archaea? What makes them similar?
3. How does the process of Natural Selection work?

Answers:

1. Animals, despite their vast differences, are similar in many ways.  Some properties that all animals possess include order, regulation, growth and development, energy processing, response to the environment, reproduction, and evolutionary adaptation, all of which are very important to their survival.  Order means that all animals show complex organization.  Regulation is important because, though the environment can change at any given time, an animal can keep its internal environment within limits that sustain life.  The important thing about growth and development is that heredity dictates its pattern in an organism.  Energy processing refers to the tendency of organisms to take in energy and transform it to perform all of life's activities.  Response to the environment concerns all organisms because every one responds to environmental stimuli.  All organisms also participate in the reproduction of their own kind.  Evolutionary adaptation refers to the changes that evolve over many generations as animals with the best traits pass them to their offspring.
2. Domain Bacteria and Domain Archaea are both made up of prokaryotes.  For a time they were combined into the same kingdom, but new evidence regarding DNA and other molecules suggests that they are completely different branches of life.
3. Natural selection is a mechanism by which populations adapt and evolve.  The individual organisms who happen to be best suited to an environment survive and reproduce most successfully, producing many similarly well-adapted descendants. After numerous such breeding cycles, the better-adapted dominate. 

Important Facts:
1. The levels of biological organization goes as follows: Biosphere, ecosystem, community, population, organism, organ, tissue, cell, organelle, molecule, and finally the atom.  Each level greatly affects the following level, just as it is substantially affected by its preceding levels. Each part helps define the emergent properties of its whole.
2.  In an ecosystem, chemical nutrients participate in an essential cycle.  They are passed from the atmosphere and the soil to producers to consumers to decomposers and then back to the environment. Energy only flows through an ecosystem once.  It passes from the sun to producers then to consumers and exits as heat.
3. The basic unit of life is the cell which performs all the necessary duties required for life.  Eukaryotic cells are enclosed in a membrane and contain a DNA-containing nucleus.  Prokaryotes lack the afore mentioned organelles and are much smaller.
4.  DNA is the genetic information that programs all inherited traits and the production of an organism's molecules.  All genes are coded in sequences that always contain the same four building blocks.
5.  There are different names and classifications for every species.  Some are classified under Domain Bacteria or the Domain Archaea, both of which include only prokaryotic cells.  The rest are classified under Domain Eukarya, which includes only eukaryotic cells.  Various different protist kingdoms emerge from this domain.  They are the kingdoms Fungi, Bacteria, and Animalia.
6. Natural selection is best defined as an editing mechanism that occurs when populations of organisms with inherited variations, having been exposed to environmental factors that favor them over others, have more reproductive success and so pass their genes on to their descendants.

Diagram-  This focuses on the cycling of chemical nutrients and flow of energy in an ecosystem. 

Summary: Chapter one focuses on life's hierarchy of organization.  It talks about the cycling of nutrients and flow of energy in an ecosystem as well as the cell.  It discusses DNA and its importance to life as well as the three domains of organisms.  The chapter also covers the theories of evolution and natural selection and how they're important to life.  It then includes the processes of science.

Key Terms
Biosphere-All  the environment on Earth that supports life.
Ecosystem-All the organisms living in a particular area, including the nonliving components of the environment.  (water, air, soil etc.)
Community- The entire range of organisms living in an ecosystem.
Population- Consists of all the individuals of a species living in a specified area. EX: lions inhabiting a savannah.
Organism- An individual living thing.
Organ System- Consists of several organs working together in performing specific functions.  EX: digestive system, nervous system etc.
Tissues- Make up organs.  Several different types, each with a specific function and made up of similar cells.
Organelle- A membrane bound structure that performs a specific function in a cell.
Molecule- A cluster of atoms held together by chemical bonds.
Prokaryotic cell- Simpler, and usually smaller than a eukaryotic cell.  Make up microorganisms called bacteria. 
Eukaryotic cell- Makes up forms of life such as animals, plants, and fungi.  It is subdivided by internal membranes into many different functional compartments or organelles.


Video:  
http://www.youtube.com/watch?v=GcjgWov7mTM