UNIT 14 ECOLOGY Founder of Ecology n Ernst

UNIT 14 – ECOLOGY

Founder of Ecology n Ernst Haeckel – “Oikos”

A. Introduction Ecology is the study of interactions between organisms and their environment; therefore the study of ecology includes biotic, or _____ living factors, as well as abiotic (____) non-living factors. n

B. Levels of Organization Species - a group of similar organisms 1. _______ that can interbreed and produce fertile offspring

B. Levels of Organization n n Population - a group of organisms that belong to 2. _____ the same species and live in one area. The area in habitat which an organism lives is known as its ____. 3. Community _______ - many different species of habitat organisms living in the same ______ abiotic Ecosystem - a community and the _______ 4. ______ factors that affect it Biome - a group of ecosystems that have the 5. _______ communities same climate and similar _______ Biosphere - Earth 6. ______

IV. ENERGY FLOW (pp. 67 -73) All living things require energy. The ultimate source of energy for the earth is the ____. sun Self-feeder n A. Autotrophs – “______”. They are also known as _____. Most producers capture energy from the sun in a process called __________. Photosynthesis takes photosynthesis chloroplasts of plant cells. place in the _____ n The equation for photosynthesis is 6 O 2_. _____ +__ 6 CO 2 +6 H 2 O +_______ light energy →____ C 6 H 12 O 6 n

obtain food B. Heterotrophs – Organisms that have to _____ _ consumers are called heterotroph or ______. n n n There are several categories of consumers: plants (producers)__ 1. Herbivores – Eat __________ animals (other consumers)__ 2. Carnivores – Eat ____________ plants & animals 3. Omnivores – Eat ___________ 4. Detritivores – Obtain energy from ____ dead bodies of plants worms , _____ and animals; for example, _______ vultures , _ organic matter. Most 5. Decomposers – Break down _____ Eubacteria or Kingdom _______ Fungi_. decomposers are in Kingdom ______

C. Energy in a Cell – All organisms producers and _____) consumers (_____ must convert _____ energy present in ____ and glucose chemical other food molecules into usable energy. This metabolism conversion process is known as ______ and the end-product is a re-chargeable “battery” used by all cells for energy known as ____. ATP Most ATP is produced through the process of cellular respiration _________. n The equation for cellular respiration is C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O +ATP ___. _ ________________ n

IV. ENERGY FLOW – A COMPARISON OF PHOTOSYNTHESIS & CELLULAR RESPIRATION (p. 232) PHOTOSYNTHESIS CELLULAR RESPIRATION Function Use energy from sun to make glucose Release energy from glucose to make ATP Cell Location Chloroplasts Mitochondria Occurs In Autotrophs Heterotrophs AND Autotrophs Reactants CO 2 + H 2 O + energy C 6 H 12 O 6 + O 2 Products C 6 H 12 O 6 + O 2 CO 2 + H 2 O + energy Overall Reaction CO 2 + H 2 O + energy → C 6 H 12 O 6 + O 2 → CO 2 + H 2 O + energy

C. Tracing Energy Flow n A. Trophic Levels - Each step in the pathway of trophic level energy flow is known as a ______. The first trophic producer level is always a _____. The 2 nd trophic level is known as the primary (1 o) _consumer_ and may be an herbivore or ____ omnivore_. The last step is always a _____ Decomposer ________. n 1. Food Chains – A food chain illustrates how energy is transferred by showing _feeding relationships between organisms. The arrows energy transfer show the direction of _______– means “is eaten by”_.

Typical Food Chain n _Energy (Sun)____ → __Producer____ → _1˚ Consumer (herbivore or omnivore)____ → _2˚ Consumer (carnivore or omnivore)____ → _Decomposer_ EX: Sun-> Grass->Grasshopper->Snake->Hawk

n ·Which organism acts as a secondary consumer? n ·According to this food chain, which organism could be n described as an herbivore? n ·Which organism is the producer? n ·What are two terms that could be used to describe the hawk?

Food Webs n 2. Food Webs – Typically feeding relationships are more complex than illustrated in a food chain. Most organisms eat a______ variety organisms and are eaten by a variety of organisms. ______ These interconnected pathways are more accurately shown in a food web.

Food Webs n n n n According to this food web. . . ·How many different producers are there? ·Is the grasshopper a producer, primary, or secondary consumer? ·Is the grasshopper an herbivore, carnivore, or omnivore? ·What organism(s) acts as the decomposer? ·Give an example of an organism in this food web that acts as secondary and tertiary consumer. ·If all the squirrels in the community perished, would the hawk be able to survive? Explain. ·If the grass was destroyed, which organism would be most directly affected? Explain.

Ecological Pyramids n chain or 3. Ecological Pyramids – Although in theory, a food ____ web can consist of unlimited numbers of _______ trophic food ______, levels in actuality this does not take place. On average, only 10%_ _____of the energy stored in an organism is passed to the next trophic level. _____ 90% of the energy is either used by the organism to maintain ______ homeostasis or lost as ______ heat to the environment. Because of this, most food chains typically consist of only ______ 3 or 4 trophic levels. Ecologists pyramids to represent the amount of ______ use ____ energy or trophic level _______ matter at each ________.

V. NUTRIENTS IN AN ECOSYSTEM (pp. 74 -80) Unlike energy from the sun, nutrients are only available to an ecosystem in specific quantities and must be recycled within and between ecosystems. Nutrients may ____ limiting factor become a ________when they are depleted. build biomolecules , Organisms require nutrients to _________ cells, tissues, _______ etc. Although all nutrients, including water ______ , are re-cycled, there a few nutrient cycles that are especially important. n

A. Water Cycle

B. Carbon Cycle n Organisms require carbon to make proteins carbohydrates _______, lipids _______, nucleic acids. Carbon dioxide in the and______ plants and atmosphere is taken up by _____ algae photosynthesis (Algae are ____ for _______. autotrophic, unicellular organisms with cell walls made of cellulose and chloroplasts Protista _). that belong to kingdom ____

B. Carbon Cycle n cellular respiration They produce glucose for _________. consumers eat plants & Humans and other _____ algae, or they eat other organisms who have eaten plants & algae. The carbon from glucose CO 2 a waste is returned to the atmosphere as _____, product of cellular respiration. In addition, fossil fuels and erosion, burning of _____, decomposition ________ recycle carbon.

Carbon Cycle

C. Nitrogen Cycle n n Nitrogen Cycle – Organisms require nitrogen to proteins and nucleic acids build __________. atmosphere is mostly nitrogen, but only The ______ bacteria produce the _______ enzymes needed to convert _______ nitrogen from the atmosphere to a useable form, nitrogen fixation a process known as _________. After nitrogen fixation is carried out by bacteria in soil, the nitrogen compound in the soil is then plants absorbed by ____ and used to make proteins nucleic acids ______& ______.

Nitrogen Cycle n When other organisms eat plants and algae ___________, they can reuse the nitrogen to build their own proteins_ and ______. nucleic acids _______ When decomposers return the organisms die, ______ nitrogen to the soil where it may be taken plants again or returned to the up by ______ bacteria atmosphere by other _____.

Nitrogen Cycle

D. Phosphorus Cycle - All organisms require DNA RNA lipids phosphorus for____, _______, and the phospholipids bilayer __________of the cell membrane. Phosphorus is found in soil and rocks, absorbed roots by the ______of plants, where it is transported xylem through the rest of the plant by the______. Consumers ______eat plants, which is then returned to the soil n

Phosphorus Cycle

E. Nutrient Limitation n n E. Nutrient Limitation – When nutrients are scarce in an ecosystem, they are described limiting nutrient as________. This imposes restrictions on the number of organisms, an organism’s growth, and the ________of primary productivity the system. For example, run-off from fertilized fields can trigger algae blooms in aquatic systems.

Algla Blooms

VIII. ECOLOGICAL SUCCESSION (pp. 94 -97) n n Ecosystems are constantly changing in response to natural and human disturbances. As an ecosystem changes, older inhabitants gradually die out and new organisms move in, resulting in further changes in the community. Ecological slow succession refers to a series of _____changes physical environment that occur in a __________over time.

A. Primary Succession n n A. Primary Succession – Occurs following destruction of an_____; ecosystem for example, after Volcanic eruption, glaciers melting: First species to populate area known as _______species pioneerafter a Lichens are the most common pioneer species volcano because they are capable of growing on bare rock. A lichen is a fungus and cyanobacteria living together. Cyanobacteria are photosynthetic bacteria. In a lichen, the cyanobacteria provides food for the fungus and the fungus provides water and protection for the cyanobacteria.

Primary Succession

B. Secondary Succession n B. Secondary Succession – Occurs when a disturbance of some kind changes an existing community without removing wildfire the soil; for example, _____, clearing plowing for farming land, ________.

Secondary Succession

IV. n ECOSYSTEM INTERACTIONS (pp. 90 -93) Ecosystems are influenced by a combination of biological and physical factors. Together biotic factors and abiotic factors determine the health of an ecosystem and its _inhabitants_.

The Niche n A. The Niche - The role an organism plays in its _community is its _niche. An organism’s niche is comprised of _biotic_and _abiotic_factors, for example, the type of food it eats, how it obtains its food, the way it is food for other organisms, how & when it reproduces, its physical living requirements to survive, etc.

Warbler’s Niche

B. Interactions Within a Community interactions have a powerful effect on an ecosystem: n 1. Competition – Competition occurs when organisms are attempting to use the same _resources at the same time. Each different species within a community must have its own _niche_.

Predation n 2. Predation – The organism that does the killing and eating is the _predator and the food organism is the _prey_.

3. Symbiosis – A relationship in which two organisms _live very closely together is described as symbiosis. n n There are three main types of symbiotic relationships: a. Mutualism – Both organisms _benefit. For example, virtually all plant roots have mycorrhizae – a Fungus that resides within the plant roots. Fungus enhances absorption of water and nutrients in roots; plant provides protection for the fungus.

Commensalism n b. Commensalism – In commensalism, only one organism benefits, but the other organism _is not harmed___. For example, barnacles are small _animals__ that often attach themselves to whales. They do not harm the whales, and the barnacles benefit from the _movement of water as whale swims – provides food for barnacles___.

Parasitism n c. Parasitism – In parasitism, only one organism benefits and the other organism is _harmed__ by the relationship. The organism that is harmed is known as the _host__. Examples of parasites include _tapeworms, hookworms, ticks, lice.

V. n POPULATIONS WITHIN AN ECOSYSTEM (pp. 124 -127) Populations within an ecosystem cannot have unlimited growth. There are conditions that have an impact on population size known as _limiting factors. Limiting factors may described as density -dependent or density-independent.

A. Density-Dependent Limiting Factors n n n A. Density-Dependent Limiting Factors – Density-dependent factors depend on population size; For example, _competition__ and availability of _food___, _water__, and _sunlight__.

B. Density-Independent Limiting Factors n n B. Density-Independent Limiting Factors– These are factors that affect all populations the same way, regardless of size. Examples include _unusual weather, natural disasters__, and human activities such as_cutting down trees, damming rivers, etc__

C. Climax Community n n C. Climax Community– A climax community is a _stable community with very little population growth or decline. Each ecosystem has a _carrying capacity_, a certain number of organisms that can exist _successfully_. When the carrying capacity is exceeded, resources become a _limiting factor_, and population numbers _decline_.