The Organization of Life Chapter 4 Section 1 Ecosystems: Everything Is Connected

Notable Quote “When we try to pick out anything by itself, we find it hitched to everything else in the universe.” -John Muir, (naturalist, writer, and founder of the Sierra Club)

Bellringer 11/8/13  What things do you need for survival?  What kinds of ecosystems might produce these necessities?

Bellringer #2  For 5 minutes, write a description about the ecosystem around your house. Be sure to include answers to the following questions:  What are the names of some of the animals in your ecosystem? Common names will be fine.  What are the names of some of the plants in your ecosystem? Common names will be fine.  What are some of the things you and your family do to care for the ecosystem around your home?  What could you and your family do to better care for the ecosystem around your home?  What kinds of things can your community do to better care for the ecosystem around your home?

Defining an EcosystemEcosystem  All of the organisms in an area together with their physical environment  Ex: oak forest, coral reef, vacant lot  No clear boundaries  All are connected to each other  Ex: soil washes from a mountain into a lake; birds migrate from Canada to Mexico, pollen blows from a forest into a field

Components of an Ecosystem  Biotic and abiotic factors  Organisms  Populations  Communities

Biotic Factors  Living and once living parts of an ecosystem  Includes all plants and animals  Dead organisms  Parts of dead organisms (e.g. leaves)  Organisms’ waste products

Abiotic Factors  Nonliving parts of ecosystem  Air  Water  Rocks  Sand  Light  Temperature

How Organisms Fits Into Organization of Living Things

Activity: Round TableRound Table List the biotic and abiotic factors in the figure

Organisms  An individual living thing  Ex: you, an ant, a bacterium  Species = a group of organisms that are closely related and that can mate to produce fertile offspring  Ex: humans are in species Homo sapiens  Every organism belongs to a species

Populations  All the members of the same species that live in the same place at the same time  Ex: all field mice in a corn field, all people living in Stafford County, VA  Members usually breed w/ each other and not w/ other populations

Communities  A group of various species that live in the same place and interact w/ each other  Ex: pond (plants, fish, and insects living in and around pond)  All living things belong to one or more communities  Land communities often dominated by a few plant species (dictates what animals live there)

Habitat  The place an organism lives  Ex: howler monkey lives in rain forest  Aka “address”  Organisms are well suited for natural habitats and cannot survive long outside them  Contains specific characteristics necessary for organisms to survive in habitat  One change can have dire consequences

Quiz  For each picture, state whether it shows an organism, population, community, ecosystem, or biosphere  Explain your answer

Section 2: Evolution

Bellringer  What characteristi cs do you think help the chameleon when it hunts?

Evolution by Natural Selection  1859 – Charles DarwinCharles Darwin  Observed organisms in population differ slightly from each other in form, function, and behavior  Proposed environment exerts strong influence over which individuals survive to produce offspring  b/c of certain traits, some individuals are more likely to survive than others

Evolution by Natural Selection  Natural selection – unequal survival and reproduction that results from the presence or absence of particular traits Natural selection  Over many generations natural selection causes the characteristics of a population to changenatural selection  Evolution – a change in the genetic characteristics of a population from one generation to the next Evolution

Evolution by Natural Selection  Adaptation – an inherited trait that increases an organism’s chance of survival and reproduction in a certain environment

Parts of Evolution by Natural Selection

Coevolution  The process of evolving in response to long-term interactions with another species  Ex: honeycreeper has long beak to reach nectar in flower; flower has evolved structure so that as bird sips nectar it gets pollen on its head

Darwin’s Finches

Evolution by Artificial Selection  Many populations of plants and animals do not live in the wild but are cared for by humans  People control how they reproduce and evolve  Artificial selection – the selective breeding of organisms by humans for specific characteristics Artificial selection  Ex: dogs, fruits and vegetables

Evolution of Resistance  Sometimes humans cause unwanted adaptations  Ex: insects resistant to pesticides and bacteria resistant to antibiotics  Resistance – the ability of one or more organisms to tolerate a particular chemical designed to kill it Resistance  An organism may contain a gene that allows it to break down chemical into harmless substance  The faster an organism reproduces, the faster its populations can evolve

Pesticide Resistance

The Diversity of Living Things Section 4-3

Bellringer  How would scientists classify you?  Kingdom?  Phylum?  Class?  Order?  Family?  Genus?  Species?

Bellringer Answer  How would scientists classify you?  Kingdom? Animalia  Phylum? Chordata  Class? Mammalia  Order? Primates  Family? Hominidae  Genus? Homo  Species? Homo sapiens

Diversity  Cell – basic unit of living things; smallest unit of biological organization  Cells of animals, plants, fungi, and protists contain a nucleus (eukaryotes)  Bacteria, fungi, and plants have a cell wall

The Kingdoms of Life

Bacteria  Microscopic, single- celled organisms that usually have cell walls and reproduce by dividing in half (fission)  Archaebacteria  Eubacteria  Most bacteria  Includes disease causing and those found in garden soil  Live in every habitat on Earth, from hot springs to the bodies of animals

Bacteria and the Environment  Break down the remains and wastes of other organisms and return nutrients to the soil  Recycle nutrients, such as N and P  Ex: nitrogen-fixing bacteria  Allow organisms, including humans, to extract certain nutrients from their food  Escherichia coli in intestines help digest food and release vitamins that humans and other animals need

Fungi  Fungus – an organism whose cells have nuclei, cell walls, and no chlorophyll  Cell walls act as miniature skeletons that allow fungi to stand upright  Mushroom is reproductive structure of a fungus; rest is underground network of fibers that absorb food from decaying organisms in the soil  Release chemicals that help break down organic matter and then absorb nutrients

Fungi  Some cause disease  Athlete’s foot, ringworm  Add flavor to food  Fungus in blue cheese gives cheese its strong flavor  Yeast make bread rise