TOPIC 4.1 ECOLOGY IB DP – CORE 1 Amit Mishra - NES International School Mumbai.

Topic 4.1 EcologyIB DP – CORE

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Essential idea:

•The continued survival of living organisms including humans depends on sustainable communities.

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Nature of science: :

•Looking for patterns, trends and discrepancies—

(i.e. Discrepancy -- plants and algae are mostly autotrophic but some are not. )

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Assessment Statement

Define species, habitat, population, community, ecosystem and ecology

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Basic Concepts• Species : a group of organism that can interbreed & produce fertile offspring.(have a common gene pool).

• Habitat: the environment in which species normally lives (location).

• Population: a group of the organism of the same species ,living in the same area at the same time.

• Community: a group of populations living & interacting with each other in an area.

• Ecology: the study of relationships between living organisms & their environment.

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Environment

• Its everything which surrounds an organism.• It has 4 main components

• Hydrosphere (water)• Atmosphere (gases)• Lithosphere (rocks)• Biosphere (all living beings)

• The first 3 are abiotic components while the 4th is the Biotic component

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Assessment Statement

Distinguish between autotroph and heterotroph.

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Autotrophs & heterotrophs

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• Autotrophs are the species with the capacity to make their own food.• Eg.:cynobacteria, Algae,Grass, Trees.

• Hetrotrophs are the species which do not have the capacity to produce their own food.• Eg.:animals,fish,zooplanktons.• Three type of heterotrophs :

1. consumers 2. detritivore 3. saprotroph

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Assessment Statement

Distinguish between consumers, detritivores and saprotrophs

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Detrivores & saprotrophs• Detrivores are the organism that consumes dead organic

matter.• Eg.: earthworm, woodlice.

• Saprotrophs are the organisms that live on, or in, dead organic matter. (digesting the food by secreting enzymes)

• Eg. Bacteria, Fungus.

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15 minute Vocabulary Practice

• Study Individually – 3 minutes• Read the definition to your partner – your partner guesses definition – 3 minutes

• Switch with partner. – 3 minutes• Read vocabulary word to partner – Partner describes definition – 3 minutes

• Switch – 3 minutes

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Vocabulary Practice

• Autotroph: • Heterotroph:• Consumer: • Detritivore: • Saprotroph:

• Species.• Habitat.• Population.• Community• Ecosystem: • Ecology:

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Assessment Statement• State that saprotrophic bacteria and fungi (decomposers)

recycle nutrients.

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Assessment Statement

Explain that energy can enter and leave an ecosystem, but that nutrients must be recycled.

Energy enters as light and usually leaves as heat.

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Nutrient Cycles• All the chemical substances that an organism needs to sustain life are its nutrients.

• Every living organism needs nutrients to build tissues and carry out essential life functions.

• Nutrients are passed between organisms and the environment through biogeochemical cycles.

•Nutrient Cycle

Nutrient Cycle vs. Food ChainNutrient Cycle vs. Food Chain

Food Chain

The Carbon Nutrient Cycle

CO2 in Atmosphere

Photosynthesis

feeding

feeding

Respiration

Deposition

Carbonate Rocks

Deposition

Decomposition

Fossil fuel

Volcanic activity

Uplift

Erosion

Respiration

Human activity

CO2 in Ocean

Photosynthesis

IB Assessment Statement Distinguish between organic and inorganic nutrients. (Compounds containing carbon that are found in living organisms (except hydrogencarbonates, carbonates and oxides of carbon are regarded as organic.)

Organic Nutrients/ Compounds• Organic Compounds are compounds containing carbon

found in living things• BUT there are exceptions are classified as NON-organic

• Carbon dioxide (CO2)

• Carbon Monoxide(CO).

• Hydrogen Carbonates (HCO3- )

Overview: Carbon—The Backbone of Biological Molecules• Although cells are 70–95% water, the rest consists mostly of carbon-based organic compounds

• Carbon is unparalleled in its ability to form large, complex, and diverse molecules

• Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds

Inorganic Nutrients Species need to survive•Living organisms need a supply of chemicals elements from the environment.

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Essential Elements of Life

• About 25 of the 92 elements are essential to life• Carbon, hydrogen, oxygen, and nitrogen make up 99% of

living matter• Most of the remaining 1% consists of calcium,

phosphorus, potassium, iron and sulfur

Autotrophs vs. Heterotrophs• Autotrophs obtain all the elements they need from

inorganic sources, include carbon and nitrogen

• Heterotrophs obtain carbon and nitrogen from their food (other living organisms). They do obtain other inorganic elements such as sodium, potassium and calcium from the abiotic (non-living world)

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Sustainability of Ecosystem• Something is Sustainable - if something that can continue

indefinitely

• There are three requirements for sustainability1. Nutrient availability

2. Detoxification of waste products

3. energy availability

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Mesocosms – Lab/ practical 5• Mesocosm are small experimental areas that are set up

as ecological experiments.• i.e. Small fenced off enclosures in grasslands and forests can be

used –VIDEO – EVOLUTION minnows in MEXICO illustrates mesocosms

• We will create a sustainable mesocosm for a lab.

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Community & Populations SKILL• A community is formed by populations of different species

living together and interacting.

• SKILL : Test for the association between species using Chi-Square Sampling with data obtained by quadrat sampling.

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Chi-Square Tutorial • https://www.khanacademy.org/math/probability/statistics-

inferential/chi-square/v/pearson-s-chi-square-test-goodness-of-fit

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