The Organization of Life Chapter 4

Ecosystems  Ecosystem- all the organisms living in an area together with their physical environment.  Ecosystems are connected. “ When we try to pick out anything by itself, we find it hitched to everything else in the universe.” – John Muir

Ecosystems

Ecosystems  Components of the ecosystem- –Biotic- living or once living portion of an ecosystem. –Abiotic- nonliving portion of the ecosystem.  Ex.- Light, sand, rocks, air, water

Ecosystems

Ecosystem  Components of an ecosystem- –Organisms- an individual living thing. –Species- a group of organisms that are closely related and that can mate to produce fertile offspring. –Populations- all members of the same species that live in the same place. –Communities- a group of various species that live in the same place and interact.

Ecosystems

Ecosystems  Habitat- the place an organism lives.  Niche- the role an organism plays in an ecosystem. What the organism does to survive and meet its needs.

Ecosystems

Evolution  Evolution- genetic change over time. –Darwin proposed that an environment exerts a strong influence over which individuals survive and reproduce. –Natural selection- some individuals are more likely to survive and reproduce because of certain characteristics they have.

Evolution

Evolution

Evolution  Adaptation-an inherited trait that increases an organisms chance of survival and reproduction.  Coevolution- the process of genetic change due to long term interaction between two organisms.

Evolution  Artificial selection- Human controlled breeding of organisms for specific traits. –Wolves  Dogs –Native grains  Wheat

Evolution  Evolution of Resistance –Resistance- the ability of one or more organisms to tolerate a particular chemical designed to kill it.  Pesticide resistance

Diversity of Living Things  Learn this chart– p. 102 in your textbook.

Diversity of Living Things  Bacteria –Single celled –Prokaryotic –2 kinds  Archaebacteria and Eubacteria –Break down waste, recycle materials, help with digestion in more complex organisms, cause illness

Diversity of Living Things  Fungi –Eukaryote –Have cell wall made of chitin –Extracellular digestion –Breakdown organic matter, recycle materials, cause disease, food for humans

Diversity of Living Things  Protist –Eukaryote –Very Diverse group  Animal like- amoeba  Plant like- kelp  Fungus like –Some cause disease- plasmodium = malaria –Plantlike protist (algae) make up the base of all aquatic food chains.

Diversity of Living Things  Plants –Multi-celled eukaryotes –Cells walls made of cellulose –Photosynthesize –Most have vascular tissue- a system of tubes that carry water and nutrients –Nonvascular plants  No vascular tissue  Swimming sperm- require water for reproduction  Ex.- ferns and club mosses

Diversity of Life  Plants-con’t –Gymnosperms  Woody plants  Seeds are not covered by fruits  Produces pollen for reproduction- wind  Ex.- conifers

Diversity of Life  Plants –Angiosperms  Flowering plants  Seeds protected by fruit  Produces pollen for reproduction- wind, insects, animals  Most land plants are angiosperms

Diversity of Life  Animals –Eukaryotic –Heterotrophic- can not produce its own food –Mobile

Diversity of Life  Invertebrates –Lack backbones –Ex- coral, octopus, insects

Diversity of life  Vertebrates –Have backbone –Land and water dwelling –Warm blooded animals can survive cold climates (birds and mammals)