Questions and Answers
What is the primary source of energy for almost all life on Earth?
Energy from the sun takes approximately 8 minutes to reach Earth.
True
What percentage of solar radiation is estimated to be converted to chemical energy by photosynthesis?
1% to 2%
The sun has been emitting energy for about _____ years.
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Match the following terms with their definitions:
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What is produced during fusion in the sun?
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Only a small fraction of solar radiation reaches plants and photosynthetic organisms.
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How many joules of solar radiation bombards Earth each day?
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The sun's energy radiates in _____ directions through space.
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What does the 10% law refer to?
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Study Notes
Branches of Ecology
- Global ecology focuses on the interactions between ecosystems at a planetary scale.
- Ecosystem ecology studies the flow of energy and cycling of nutrients among the biotic and abiotic components of ecosystems.
- Community ecology examines the interactions and relationships among different species in a community.
- Population ecology investigates the dynamics of species populations and how these populations interact with the environment.
- Physiological ecology explores how individual organisms adapt to environmental conditions.
Ecosystem Components
- An ecosystem comprises both living (biotic) and non-living (abiotic) factors surrounding organisms.
Biotic Components
- Producers: Autotrophs that synthesize their own food; examples include green plants on land and algae in aquatic environments.
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Consumers: Heterotrophs that cannot produce their own food, classified into:
- Herbivores (primary consumers) like sheep that eat plants.
- Carnivores (secondary or tertiary consumers) like lions that consume other animals.
- Omnivores, such as humans, that eat both plants and animals.
- Decomposers, which break down detritus into inorganic matter, recycling materials in ecosystems.
Abiotic Components
- Minerals: Essential solid components of soil providing necessary elements and chemical compounds for life.
- Water: Constitutes a major part of ecosystems, found in rivers, lakes, and oceans.
Photosynthesis vs. Chemosynthesis
- Photosynthetic organisms: Utilize sunlight to produce organic molecules; examples include green plants and algae, and they release oxygen.
- Chemosynthetic organisms: Some bacteria oxidize inorganic substances to produce organic matter; do not release oxygen, e.g., certain nitrite and nitrate bacteria.
Auto-Heterotrophic Organisms
- Euglena: Unicellular organisms that exhibit both autotrophic (in light) and heterotrophic (in the dark) nutrition.
- Insectivorous plants: Such as Dionea and Drosera, carry out photosynthesis but obtain nitrogen from insects due to nutrient-deficient soil.
Parasitic Plants
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Full-parasitic plants: Lacking chlorophyll, relying entirely on their host for nutrition through haustoria.
- Examples include Broom-rapes and Cuscutaceae.
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Half-parasitic plants: Possess chlorophyll and can photosynthesize while also obtaining nutrients from the host's xylem.
- Examples include mistletoe.
Pathogens
- Bacteria and fungi that parasitize higher plants and animals, causing diseases.
- Obligate parasites: Cannot survive without a host; includes viruses and specific bacteria.
Trophic Levels
- Primary consumers: Herbivores feeding on plants.
- Secondary consumers: Feed on herbivores; often carnivorous.
- Tertiary consumers: Feed on secondary consumers.
- Decomposers: Mainly bacteria and fungi that recycle nutrients by breaking down organic matter.
Food Webs
- Ecosystems have complex food webs where food relations are interconnected rather than linear chains.
- Energy decreases from primary producers (first trophic level) to secondary and tertiary consumers, following the "10% law" concerning energy transfer efficiency.
Energy from the Sun
- The sun, average in size, emits energy that travels 93 million miles to Earth in approximately eight minutes.
- Solar fusion results in substantial energy output, transforming a tiny mass loss into energy.
- The sun has emitted energy for around five billion years and is expected to continue for an equivalent duration.
- Only a small fraction reaches Earth; absorbed differently by land and water.
- Only 1% to 2% of the visible light that strikes photosynthetic organisms is converted into chemical energy through photosynthesis.
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Description
Explore the various branches of ecology including global, ecosystem, community, population, and physiological ecology. This quiz will test your understanding of ecosystem components and the differences between biotic and abiotic factors. Enhance your knowledge about the crucial roles of different organisms in various ecosystems.
