Chapter 1: Living Things Aim: What is the difference between living and nonliving things?

Characteristics of Living Things Organized Grow and develop Reproduce Respond to stimuli Maintain certain internal conditions Use energy Things that have ALL of these characteristics are called organisms

Organized Made up of small units called cells Cells contain structures with specialized functions Some organisms are unicellular (one cell only) Some are multicellular (two or more cells) Each cell contains heredity material and has a structure Growth and Development Unicellular organisms grow as the cell increases Multicellular organisms grow as their cells increase in number Changes that occur in an organism during its lifetime are called development

Reproduce Reproduction is the process by which one organism makes one or more new organisms All organisms reproduce differently Respond to Stimuli All living things respond to changes in their environment Changes can be internal or external Internal stimuli: ex: feeling hungry or thirsty External stimuli: ex: light and temperature Homeostasis An organisms ability to maintain steady internal conditions when outside conditions change

Ensures that cells can function Energy Cells use energy to transport substances, make new cells, and perform chemical reactions Everything an organism does requires energy Energy comes from the sun directly or indirectly

Nonliving Things Don’t have all of these characteristics Don’t need things in order to survive Examples: Water Air Rocks Clouds

Aim: How do we classify living things?

Classification Aristotle was one of the first people to classify organisms He classified living things into two large groups, plants and animals Animals were classified by the presence of “red blood”, animal’s environment, shape and size of the organism Plants were classified according to structure and size and whether the plant was a tree, shrub, or herb

Robert H. Whittaker proposed a five-kingdom system. Carolus Linnaeus came up with a new system of classification based on the structures of the organism Organisms were placed into to kingdoms Robert H. Whittaker proposed a five-kingdom system. Kingdoms: Monera, Protista, Plantae, Fungi and Animilia

Today’s Classification System Is called systematics Uses all evidence known about an organisms to classify them Cell type Habitat way organism obtains food and energy structure and function of features Common ancestry Molecules within organism, such as DNA

The six kingdoms are separated into one of the three domains: This new system led to the development of another level of classification called domains. The six kingdoms are separated into one of the three domains: Bacteria Archaea Eukarya 6 kingdoms are: Bacteria, Archaea, Protista, Fungi, Plantae, Animalia

Aim: How do scientists name organisms?

Binomial Nomenclature Two-word naming system developed by Linneaus that scientists still use today First word identifies the genus of the organism The second word is the species, which may describe the organism’s appearance or its behavior Examples: Brown Bear=Ursus arct0s

Using Scientific Names Scientific names are the same worldwide Communication about organisms are more effective because of scientific names

Aim: What tools do we use to help with classification?

Tools for Identifying Organisms Dichotomous keys A series of descriptions Arranged in pairs Identifies an unknown organism Choices continue until the organism is identified

Cladograms a branched diagram that shows the relationships among organisms, including ancestors Has a series of branches Each follows a new characteristics Each characteristic is observed in all the species to its right