Chapter 3

The Biosphere

3.1 Ecology

• The study of interactions btw living organisms & their env.

• Biosphere – whole planet where life is– 8km above– 11km below

3.1 Ecology

• Individual – a single organism• Species – group of similar orgs • Population – groups of same species inds

that live in same area• Community – pops. that live in defined area• Ecosystem – orgs & env in a defined area• Biome – group of ecosystems w/ same

climate• Biosphere – whole planet where life is found

3.2 Energy Flow

• Food energy from Ch 38

• Food chain/web– Differences

• Chain pg 69• Web pg 71

3.2 Energy Flow

• Producers– All living organisms need energy– Most organisms use light energy from

the sun• A little goes a long way!

– Some organisms use chemical energy– aka Autotrophs

• Orgs. able to use energy in env. (sun or chem.)

• Make their own food

3.2 Energy Flow

• Energy from the Sun

– CO2 + H2O carbs + O2

• Types – Plants– Algae– Photosynthetic bacteria

• Cyanobacteria most common

Light eng.

3.2 Energy Flow

• Energy from Chemicals– Produce food in the absence of light– Use inorganic molecules to make

organic molecules– Chemosynthesis – Mostly bacteria in volcanic areas & deep

sea vents

3.2 Energy Flow

• Consumers– Eat other organisms– aka heterotrophs– Types

• Herbivores – eat only plant material• Carnivores – eat only animal material• Omnivores – eat both plant & animal material• Detritivores – eat plant & animal remains

(detritus)• Decomposers – break down organic matter

3.2 Energy Flow

• Feeding Relationships– Energy flows one way– Energy is never lost, only converted

• Food Chains– Linear relationship btw. producers &

consumers

3.2 Energy Flow

• Food Webs– Too complex for a linear representation

• Trophic Levels– Producer– Primary consumer– Secondary consumer– Etc.– Decomposers

3.2 Energy Flow

• Ecological Pyramids– Amt. of energy matter/# orgs. at each

level – 10% energy passed on from one trophic

level to the next– 90% lost as heat energy

• Biomass Pyramid– Amt. living mass at each level– Amt. food

3.3 Cycles of Matter

• Energy FLOWS – Linear– Converted: light food chemical heat– At end, lost as heat

• Cycles– Continuously recycled

• Water pg 75• Carbon pg pg 77• Nitrogen pg 78• Phosphorous pg 79

Skim!

Definition of “living”Conventional definition: Often scientists say that life is a

characteristic of organisms that exhibit the following phenomena:

• Homeostasis: Regulation of the internal environment to maintain a constant state; for example, sweating to reduce temperature.

• Organization: Being composed of one or more cells, which are the basic units of life.

• Metabolism: Consumption of energy by converting nonliving material into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.

• Growth: Maintenance of a higher rate of synthesis than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter. The particular species begins to multiply and expand as the evolution continues to flourish.

Definition of “living”

• Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.

• Response to stimuli: A response can take many forms, from the contraction of a unicellular organism when touched to complex reactions involving all the senses of higher animals. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun or an animal chasing its prey.

• Reproduction: The ability to produce new organisms. Reproduction can be the division of one cell to form two new cells. Usually the term is applied to the production of a new individual (either asexually, from a single parent organism, or sexually, from at least two differing parent organisms), although strictly speaking it also describes the production of new cells in the process of growth.

From Wikipedia

4.2 What Shapes an Ecosystem?

• Factors– Living/biological

• Biotic– What the org eats– Amt of food available– What eats the org.

– Nonliving/physical• Abiotic

– Temperature– Climate– Shelter

4.2 What Shapes an Ecosystem?

• Niche– Physical & biological (abiotic & biotic)

conditions as well as how it responds to/uses the conditions• Diet• Predators• How it hunts/gathers food• Living conditions• When/how reproduce• How develop (grow up)

4.2 community interactions

• Competition– 2 orgs use same resource at same timeany necessity of life– Try to occupy similar niche– Competitive exclusion principle

• No 2 species can occupy same niche

• Predation– Predator/pray

• Symbiosis– 2 species live closely together

• Mutualism– Both species benefit

• Commensalism– One species benefits, the other is neither helped

nor harmed

• Parasitism – One species benefits, the other is harmed

4.2 community interactions

4.2 Ecological Succession

• Disturbance causes destruction of env. and species die-off

• Primary– On land where there is no soil/organic

matter, ie bare rock– Pioneer species

• 1st species into a desolate area

• Secondary – Organic material still present

5.1 How Populations Grow

• Geographic distribution– aka range– Area where a population lives

• Population density– Number of individuals per unit of area

• Ex: as of 2000, Concord pop. = 121,780 Inds/area = 121,780 ppl/Concord

• Growth rate– Rate that # of inds. grows w/in a pop.

5.1 How Populations Grow

• Growth rate– Population growth

•Births

•Deaths

•# inds. leave/come to an area (emigration/immigration)

5.1 How Populations Grow

• Exponential growth– Unlimited resources– Compare graphs on pg 121

•How are these graphs alike?•Besides showing dif. orgs., how are

they graphs different?•What do these differences tell you

about the different species?•What is another difference btw how

elephants and bacteria reproduce?

5.1 How Populations Grow

• Logistic growth– Growth slows/stops– Carrying capacity

• Limit of inds that can live in a given area based on the available resources

5.2 Limits to Growth

• Limiting factors– Density-dependent

• Competition, predation, parasitism, disease

– Density-independent• Abnormal weather, natural disasters, season

cycles, human activity

5.3 Human Population Growth

• Exponential (graph pg 129)• Note historical events• Factors that effect human population

growth: war, famine, disease, social/economic

• Age structure diagrams (pg 131)

Sub work 10/17

• Due at end of period– Pg 118 Inquiry Activity– Pg 123 Analyzing Data

• Due on test day– Workbook 5.1, 5.2, 5.3 (due test day)

• Test Thursday

•Write on sep. sheet of loose leaf paper•Name, date, period upper left corner•Name of assignment top line right corner•Grade: neatness & completeness

Test Review

• How to study:– Keep up with reading HW & do workbook

• If no workbook, answer end of section questions and any other questions provided in the text

– Keep a vocab. list/make flash cards– Read & understand any pictures, tables,

charts, or graphs– Go back through text & notes looking for

key/repeated concepts or topics– As you review, jot down any questions or

topics that are still unclear

Test Review – Main Topics

• Vocabulary– 3.1 (pg 63)

• Ecology• Biosphere• Species• Population• Community• Ecosystem• biome

– 3.2 (pg 67)• Autotroph/producer• Photosynthesis• Chemosynthesis• Heterotroph/consumer• Herbivore• Carnivore• Omnivore• Detritivore• Decomposer• Food chain• Food web• Trophic level• Ecological pyramid• biomass

Test Review – Main Topics

• Vocabulary– 3.3 (pg 74)

• None

– Concepts• Energy flows

linear• Matter cycles

– Carbon– Phosphorus– Nitrogen – Water

» Evap./transp.» Condensation» Precipitation

– 4.2 (pg 90)• Biotic factor• Abiotic factor• Habitat• Niche• Resource • Comp. exclude. princ.• Predation• Symbiosis• Mutualism• Commensalism • Parasitism• Ecological succession• Primary succession• Pioneer species• Secondary succession

Test Review – Main Topics

• Vocabulary– 5.1 (pg 119)

• Population density• Immigration• Emigration• Exponential growth• Logistic growth• Carrying capacity

– 5.2 (pg 124)• Limiting factor• Density-dependent• Density-independent• Predator-pray

relationship

– 5.3 (pg 129)• Demography• Demographic transition• Age-structure diagram