Sci (Ecology) Flashcards
What is Ecology?
- Study of the relationship between biotic factors with other living organisms and their nonliving environment (abiotic factors
- Biotic factors: animals, plants, bacteria, fungi, protists
- Abiotic factors: water, O2, rocks, sand, soil, light, temperature, wind, pH
How the body is organized?
- Smallest units of living things are molecules (chemical elements bonded together into compounds), ex. Oxygen, carbon dioxide, glucose, proteins.
- Molecules are organized into functioning, living units called cells, nerve cells, etc.
- The cells are grouped together by their specialized functions into tissues, e.g., epidermal tissues, nervous tissues, etc.
- Tissues are assembled into organs, each with a special function to perform, e.g., heart, liver, kidney.
- Organs are organized into systems. Each system has major functions, e.g., respiration, circulation, digestion
- The systems of the body are coordinated and integrated into the total living body. Each is important but dependent upon the others.
Organization of living matter
- Matter is organized by organisms to populations to communities to ecosystems all under one biosphere.
Ecology Overview
- From the levels of biological organization, ecology begins with the entire organism and extends to the biosphere. Ecology is the study of the relationships between living organisms (biotic factors) with each other and between living organisms and their non-living (abiotic factors) environment.
Earth’s Spheres:
- Earth’s atmosphere: the earth’s gravity holds gases near its surface. It extends 100km up, it is critical to life on earth, and is composed of 78% N2, 21% O2, <1% Ar + H2O vapour, CO2. It also acts like a blanket and moderates surface temperatures.
- Atmosphere: the layer of gases surrounding Earth.
- Lithosphere: Rocky solid outer shell of Earth (50-150 km thick).
- Hydrosphere: Regions of water on/above/below the Earth’s surface. All of Earth’s water in solid-liquid-and-gas form.
- Biosphere: Region on the planet which can support life. Layer of ground, water, and lower atmosphere.
Gaia Hypothesis:
James Lovelock proposed that Earth, through interactions among the 4 spheres, behaved like a living organism. He suggested that Earth was capable of responding to changes in the environment (such as incoming sunlight) and maintaining relatively consistent internal conditions over long periods of time - just like a living cell.
Earth’s mass is related to…
its ability to have an atmosphere as it creates a force strong enough to hold gases near its surface.
The atmosphere enhances conditions of life on Earth because it acts like a…
blanket and moderates surface temperatures. The insulation prevents excessive heating during the day and cooling at night. Without an atmosphere, the surface temperature would drop from 15 degrees to -18 degrees. It also blocks solar radiation such as ultraviolet light (linked to skin cancer). Without an atmosphere, most species would die.
Biosphere describes the locations in which…
life can exist within the 4 spheres. Most of the easily observed life forms exist on land and in water, but micro-organisms exist several km beneath the surface. The biosphere is found within each of these spheres.
Though the Earth is large, scientists consider the biosphere to be…
as fragile as it is thin compared to Earth. All conditions required for life must be met and maintained within this thin layer of ground, water, and lower atmosphere.
Ecology:
It is the study of the relationships/interactions between biotic organisms with each other and their abiotic environment (ex. Everything that affects organism during lifetime)
Biotic:
The living factors that affect an ecosystem; living things, their remains, and features, such as nests, associated with their activities ex. all living organisms in a pond
Abiotic:
The non-living factors that affect an ecosystem ex. physical factors (temperature, light, precipitation, wind, etc.) & chemical factors (pH, oxygen levels, soil content (Fe, Mg, nitrates)) The non-living physical and chemical components of an ecosystem.
Habitat:
The place where an organism lives eg. organisms: snail, earthworm; habitats: marsh, soil
Niche:
The total role of an organism in an ecosystem ex. the niche of a deer is to: feed on grass and other plants, become food for wolves, provide blood for mosquitoes + etc, fertilize soil with its waste, reproduce
Trophic Levels:
feeding levels (position in a food chain within their ecosystem) used to classify organisms in an ecosystem. The level of an organism in an ecosystem depending on its feeding position along a food chain.
1) Producer
2) Consumers
3) Decomposer
Producer:
Also known as autotrophs (self-feeder) - organism that can make its own food through photosynthesis;
Consumers:
Also known as the heterotrophs (other feeder) - organism that cannot produce ITS OWN food, and must consume other organisms.
Herbivores:
Consumer that eats only plants - deer, rabbits, elks, cow, buffalo
Carnivores:
Consumer that eats only animals - hawks, lion, wolf, alligator, hyena
Omnivores:
Consumer that eats both plants and animals - foxes, racoons, humans, pig
Predator:
A carnivore which feeds on live animals
Prey:
The live animal which is killed and eaten by a predator
Parasite:
Organism that uses another organism as a home and source of food
Host:
Organism that the parasite lives on
Decomposer:
An organism that breaks down and feeds on nonliving organic matter (dead plants, animal, and animal wastes). Returning valuable nutrients to the environment, so that they can be re-used by producers ex. bacteria, fungi (moulds, yeast, etc.)
Levels of organization:
- Organism
- Population
- Community
- Ecosystem
- Ecotone
- Biome
- Biosphere
Organism:
An individual living thing
Population:
A group of organisms of the same species
Community:
A group of various populations living together
Ecosystem:
An area in which biotic factors are interacting with abiotic factors; all the living organisms and their physical and chemical environment
Ecotone:
A transition area between two ecosystems that includes members of the community of both ecosystems;
Biome:
A large area (ex. B.C.) with a characteristic climate and geography (eg. desert, tropical rainforest)
Biosphere:
The entire region on earth in which life is able to exist
Species Interactions:
- No living organisms are in isolation. We study their ‘feeding relationships’ by examining food chains and food webs within the ecosystem.
- Food chain - shows a simple LINEAR feeding relationship. MAX: 6
- → = is eaten by
- Grass (producer) → rabbit (primary consumer/1o) → coyote - terrestrial food chain
- All food chains start with a producer.
- Other feeding relationships create food webs;A better way to represent ALL the feeding relationships within an ecosystem is to use a Food Web
Aquatic Ecosystems:
An aquatic ecosystem is an ecosystem that is based in or on water ex. Pond, puddle, ocean.
Terrestrial Ecosystems:
An ecosystem based on land
Flow of Energy Through an Ecosystem:
- The sun is the ultimate source of energy. 0.023% of light energy converted by producers to (ATP*) food (C.P.E.).
- ATP Energy = Adenosine Triphosphate (C.P.E.).
- Only 10% of energy is passed to the next trophic level. 90% of energy used by organisms for life functions.
- Elements of LIFE: C, H, N, O, P, S.; Energy in living humans is chemical bonds holding the molecules together.
Ecological Pyramids:
- Pyramid of Numbers
- Pyramid of Biomass
- Pyramid of Energy
Pyramid of Numbers:
- NOTE: the number of organisms at each trophic level indicates how many are needed to sustain life at the level above.
- Disadvantages: this system ignores the fact that equal numbers of different organisms have different masses ex. 11 mosquitoes doesn’t equal 11 birds
Pyramid of Biomass:
- NOTE: the mass at each level indicates the mass that can be sustained at the level above.
- Disadvantages: ignores the fact that equal masses of different organisms have a different energy content. Ex. 1 kg of butter doesn’t equal 1 kg of lettuce.
Pyramid of Energy:
- Food is ultimately valued by its energy content
- Units of food energy - kilojoules (KJ), kilocalories (Kcal), Calories (cal)
- This pyramid shows the flow of food energy in a food chain
- The shape of the pyramid illustrates the loss of energy into the environment as one moves through the food chain.
Cycling Matter:
- Biogeochemical cycle
- Water cycle
- Carbon cycle
- Nitrogen cycle
Biogeochemical cycle:
The movement of matter through the biotic and abiotic environment
Water cycle:
The series of processes that cycle water through the environment
Carbon cycle:
The biogeochemical cycle in which carbon is cycled through the lithosphere, atmosphere, hydrosphere, and biosphere
Nitrogen cycle:
The series of processes in which nitrogen compounds are moved through the biotic and abiotic environment
Biotic/Abiotic Influences on Ecosystems:
- Limiting factor
- Tolerance range
- Carrying Capacity
- Both biotic and abiotic factors influence where a species can live.
