Presentation on theme: "Classification systems change as scientists learn more."— Presentation transcript:
1Classification systems change as scientists learn more. Notes for B 2.3Classification systems change as scientists learn more.
2Taxonomy changes as scientists make discoveries. Early scientists described 2 kingdoms:Plants: green and nonmovingAnimals: moving organisms
3Three DomainsMicroscopes and other advances in technology show that there are basically 3 different types of cells.Kingdoms are arranged into 3 larger groups called domains: Bacteria, Archaea, and Eukarya.
4Three Domains Bacteria: includes bacteria kingdom No nucleus UnicellularVary in how they get energy
5Archaea Kingdom Archaea No nucleus (prokaryotic) Unicellular Vary in how they obtain energyDistinctive chemistry and live in extreme environments
6Eukarya Includes Kingdoms Protista, Fungi, Plantae, and Animalia Eukaryotic (have nuclei)Some unicellular, most multicellularVary in the ways they obtain foodSee chart on page B 61.
7Six Kingdoms Plantae Animalia Protista Fungi Archaea Bacteria See pages 62 and 63 for an overview of all of these kingdoms you studied in seventh grade.
8The two most familiar kingdoms are plants and animals. Carolus Linneaus divided all the species he identified into these 2 groups.Plantae DNA stored in a nucleusCan carry out photosynthesis to make sugarsContain cell walls around their cell membraneCannot move from place to placeMulticellular
9Animalia More than 90% of named species are insects. Obtain energy by eating organisms or by eating food made by other organismsCan move around for at least part of their livesMost have mouths and nervous systemsHave nuclei (eukaryotic)No cell walls
10Other organisms make up four more kingdoms. Linnaeus: called mushrooms, molds, and their relatives plantsArchaea, Bacteria, and Protista are mostly microscopic.Most organisms on Earth are classified as bacterial or archaea—prokaryotic, small, and simple.
11Protista Most unicellular Large, complex with a true nucleus Some eat other organisms.Some make their own food.Some resemble fungi.Most live in water or sea waterSeaweedsSome scientist think this should be divided into different kingdoms.
12Fungi Yeasts Molds Downy Mildew Most have cell walls Remain rooted in one placeMany act as decomposers
13Archaea Resemble bacteria in size and shape Genetic differences Appear to be related to eukaryotes, but do not have nucleiCell structure differs from bacteriaLive in many environs, especially the oceansSome live in extreme environs such as geysers, hot springs, hot vents, salty ponds etc.
14Bacteria Live nearly everywhere on Earth Helpful/harmful Unicellular Prokaryotes (no nucleus)Most have cell walls, but not the kind plants haveReproduce quickly by binary fission
15Species and environments change. Over a million species namedEstimated millions—maybe tens of millions– not yet discoveredSpecies evolve over time as individual organisms and environments change.Changes may result in pressures that affect living space, availability of food or other resources, or from other organisms.