What is Ecology?

Questions for Today: What is the Basic Building Block of Life? How many species are there in the World? What are the levels of organization of matter in nature?

Cells are the Basic Units of Life Any living organism, alive or dead, are composed of cells. The smallest and most fundamental structural and functional units of life. This is Called the Cell Theory and it states All living things are composed of one or more cells. Cells are the basic units of structure and function in living things. New cells are produced from existing cells.

Cells are the Basic Unit of Life Remember from Biology: Two Types of Cells Prokaryotic No Nucleus or membrane bound organelles Example: Bacteria Eukaryotic Contains a nucleus and membrane bound organelles Animal and Plant Cells.

Structure of a Eukaryotic Call and a Prokaryotic Cell 5

Species Make Up the Encyclopedia of Life A species is a set of individuals that can mate and produce fertile offspring. Named using the Binomial Nomenclature System developed by Carolus Linnaeus. Remember from Biology DKPCOFGS Scientific names and the rules when writing them.

Species Make Up the Encyclopedia of Life Scientists estimate that there could be 4 – 100 million species in the Environment. Best guess is 10-14 million Biologist have identified and classified 1.8 million species. Most species are insects Over half of the animal and plant species are found in the Tropical Rainforests.

Have You Thanked the Insects Today? Pollinators Eat other insects Loosen and renew soil Reproduce rapidly Very resistant to extinction 8

Species Make Up the Encyclopedia of Life In 2007, Scientists began a $100 million, 10-year project to list and describe all1.8 million known species. www.eol.org

Levels of Organization From the inclusive to the most exclusive: Biosphere Ecosystem Community Population Organism Cells Molecule Atom

Biosphere Ecosystem Community Population Organism Cell Molecule Atom Stepped Art Smallest unit of a chemical element that exhibits its chemical properties Atom Molecule Chemical combination of two or more atoms of the same or different elements Cell The fundamental structural and functional unit of life Organism An individual living being Population A group of individuals of the same species living in a particular place Community Populations of different species living in a particular place, and potentially interacting with each other Ecosystem A community of different species interacting with one another and with their nonliving environment of matter and energy Parts of the earth's air, water, and soil where life is found Biosphere Figure 3.3 Some levels of organization of matter in nature. Ecology focuses on the top five of these levels. See an animation based on this figure at CengageNOW. Fig. 3-3, p. 52