Levels of Life’s Hierarchy (Levels of Organization)

Least specific

  • Biosphere – All environments on earth that support life (Basically, the Earth and the sky above it that has living things occupying it.)
  • Biome – Major types of ecological associations that occupy broad geographic regions of land or water and are characterized by organisms adapted to the particular environments
  • Ecosystem – all living organisms in a particular area as well as the nonliving, physical components they interact with (ex. Sunlight, water, etc.)
  • Community – All living things in an area
  • Population – Single species living in a single area
  • Organism – Single individual
  • Organ System – group of organs working together for a certain function
  • Organ – 1 part of an organ system
  • Tissue – group of similar cells that do a particular function for an organ
  • Cell – Smallest unit of life (All living things are made of up one or more cells)
  • Organelle – “organ” of a cell
  • Molecule – cluster of atoms held together by chemical bonds
  • Atom - basic unit of matter made of dense nucleus (protons and neutrons) with electron cloud around it

Most specific

Biomes

  1. Tropical Forest (rain forest and dry)
  • Temperature: warm to high
  • Rainfall: varied – heavy
  • Plants: thorny shrubs, deciduous trees, & succulents. (very diverse)
  • Sunlight: little reaches the forest floor.
  • Habitats: floor –> canopy.
  • Poor soil, due to high temp & heavy rains (leaching).
  • Animals: monkeys, birds, snakes, bats, frogs – tree dwelling.
  • The Rain Forest contains about 45% of all animal species

  1. Savanna
  • Temperature: warm year round
  • Rainfall: moderate rainfall (with long periods of drought)BIOME DEFINED MAINLY BY THIS
  • Plants: grasses & scattered trees.
  • growing point below ground & resistance to periods of drought.
  • Habitats: migratory
  • Poor soil, lack of moisture, grazing animals, & fires inhibit most trees.
  • Biome is dependent upon fires to keep nutrient rich enough to support life
  • Animals: large grazing mammals, insects, burrowing animals, predators (lions & cheetahs).

  1. Deserts

•Temperature: very hot,

and cold (Antarctica)

•Rainfall: dry

•Plants: none, deep rooted shrubs, succulents.

–waxy coating to prevent water loss

–many seeds that remain dormant until it rains

•Sunlight: extreme

•Habitats: burrows, active at night

•Animals: ants, birds, rodents, lizards, snakes, & hawks.

  1. Chaparral

•Temperature: mild winter, hot summer

•Rainfall: rain in winter, dry in summer

•Plants: dense shrubs with tough evergreen leaves. Seasonal plants.

–Food reserves in roots allow for rapid growth after frequent fires.

–Seeds only germinate after hot fire.

•Animals: deer, birds, rodents, lizards & snakes

  1. Temperate grasslands (Prairies)
  • Temperature: relatively cold
  • Rainfall: rain, but periodic severe droughts
  • Plants: grass, mostly treeless
  • fire & grazing prevents tree growth
  • Habitats: bird nests on ground, burrows.
  • Animals: large grazing mammals (bison, wild horses).
  • Soil supports diverse microorganisms & small animals.
  • One of the most productive agricultural regions in the world

  1. Temperate (deciduous) Forest
  • Temperature: cold winter, hot summer
  • Rainfall: high precipitation
  • Plants: deciduous trees (oak, hickory, maple)
  • Habitats: rich soil, leaf litter, burrow
  • Animals: invertebrates, mice, shrew, squirrels, birds, bobcats, foxes, bears, & mountain lions.
  • Most destroyed by loggers & urban development.

  1. Taiga (Coniferous) Forest-

•Temperature: long cold winters, short wet summers

•Rainfall: considerable precipitation (snow)

•Plants: cone bearing evergreens

–(spruce, pine, fur)

•Habitats: soil thin & acidic

•Animals: moose, elk, bears, wolves, hares, migratory birds.

•Heavily logged.

•Largest terrestrial biome

  1. Tundra

•Temperature: extremely cold

•Rainfall: little

•Plants: no trees, shrubs, grasses, mosses, and lichens.

–Permafrost prevents deep root penetration

•Sunlight: little light for much of the winter, constant daylight in summer

•Habitats: migratory (summer is a breeding ground), high altitude, permafrost, soil continually saturated due to poor drainage and slow evaporation.

•Animals: well insulated (oxen & caribou), lemmings, fox, snowy owl.

•During the summer, clouds of mosquitoes fill the air due to the marshy ground.