# Unit 3: Biology ## Terms - `Habitat`: Placce where organisms live - `Biotic`: Living components (their remains AND features) - Bears, insects, micro-organisms, nests - `Abiotic`: Non-living components - Physical/chemical components - Temperature, wind, humidity, precipitation, minerals, air pressure - `Sustainability`: **The ability to maintain natural ecological conditions without interruption, weakening, or loss of value.** - `Community`: Individual from all of the DIFFERENT populations (communities of different species) - `Ecosystem`: Term given to the community and its interactions with the abiotic environment - `Sustainable Ecosystem`: An ecosystem that is maintained through natural processes - `Ecological niche`: Every species interacts with other species and with its environment in a unique way. This is its role in an ecosystem (e.g. what it eats, what eats it, how it behaves, etc.) - `Biodiversity`: The variety of life in a particular ecosystem, also known as biological diversity. - Canada is home to about 140 000 to 200 000 species of plants and animals. Only 71 000 have been identified. - `Species Richness`: the number of species in an area. - Diverse ecosystem = high species richness. - Higher close to the equator. - Ex. Amazon rainforest home to more than 200 species of hummingbirds, Ontario only has a single species. - `Population`: A group of organisms of one species that interbreed and live in the same place and time. - Population often change due to both **natural and artifical** factors (human activity). - `Carry Capcity`: The maximum population size of a **particular species** that a given ecosystem can sustain. - `Pollution`: harmful comtaminants released into the enviornment. - `Bioremediation`: the use of micro-organisms to consume and break down environmental pollutants. - `Photosynthesis`: The process in which the Sun’s energy (LIGHT) is converted (put together with) into chemical energy AS GLUCOSE (sugar). - `Succession`: The gradual and usually predictable changes in the composition of a community and the abiotic condtions following a disturbance. - `Producer`: Organism that makes its own energy-rich food using the Sun’s energy. - `Consumer`: Organism that obtains its energy from consuming other organisms. - `Eutrophication`: Overfertilzation of staganat bodies of water with nutrients - `Heterotrophs` Organisms that feed on others - `Bioaccumulation`: The process by which **toxins accumulate in the bodies** of animals. (Eg, DDT). **They cannot be easily excreted from the body.** - `Bioamplification`: The **increase in concentration of a substance** such as a pesticide as we move up trophic level within a food web. **It happens because of bioaccumulation**. (Sometimes called `biomagnification`). - `Oligotrophic` Bodies of water that are **low** in nutrients. (clear water, opposite to `eutrophic`). - `Watershed` (drainage basin): Area of land where **ALL WATER** drains to a single river or lake. - `Invasive Species`: A non-native species whose intentional or accidental introduction negatively impacts the natural environment. - `Population` = (Birth Rate + `Immigration` (People coming in)) - (Death rate + `Emigration`(People leaving)). - `Argoecosytems`: Is essentially an agricultural ecosystem, engineered ecosystems: urban centres, roads, etc. - `Monocultures`: cultivation of a single crop in an area. - Bad, bees can't pollinate, as there is only one crop, destruction of one crop will result in total food shortage from that crop, as we are only growing one crop. Also nutrient cycling is disrupted and less crops can be grown at the same rate. - `Pest`: Any plant, animal, or other organism that causes illness, harm, or annoyance to humans. - `Interspecific`: 2 species fighting. - `Intraspecifict`: Same species fighting. - `Watershed`: An area or ridge of land that separates waters flowing to different rivers, basins, or seas. - `Intertidal Zone`: The intertidal zone, also known as the foreshore and seashore, is the area that is above water at low tide and underwater at high tide. ## The Spheres of Earth ### Atmosphere - The layer of `gases` above Earth's surface, extending upward for hundreds of kilometers. - `78% nitrogen gas`. - `21% oxygen gas`. - `< 1% argon, water vapour, carbon dioxide & other gases`. - Critical to (almost all) life on Earth. - Acts like a **blanket & moderates surface temperature**. - Insulation prevents excessive **heating** during the day & **excessive cooling** during the night. - Average surface temperature droup from **15C to -18C**. - Blocks some **solar radiation (most ultraviolet light)**. ### Biosphere - The regions of Earth where `living organisms` exist. - Describes **the locations in which life can exist within the lithosphere, atmosphere and hydrosphere**. - Biosphere is thin in comparison to diameter of the Earth. - ALL conditions required for **life must be met and maintained within this thin layer of ground, water, and nutrients to survive**. ### Hydrosphere - All the `water` found on Earth, above and below the Earth's surface. - Includes - **Oceans** - **Lakes** - **Ice** - **Ground Water** - **Clouds** - 97% of water on Earth **is in the oceans**. ### Lithosphere - The `hard part` of Earth's surface. - **Rocky outer shell of Earth**. - Consists of: - **Rocks and minerals that make up mountains, ocean floors, and Earth's solid landscape** -Thickness: **50 - 150km**. ## Energy Flow - `Law of Conservation of Energy`: Energy **can not** be **created** or **destroyed**. It can only be transformed or transfeered. - Note that Photosynthesis and Cellular respiration are nearly **THE EXACT OPPOSITE**. ### Types of Energy - #### Radiant Energy - Energy that travels through EMPTY SPACE - #### Thermal Energy - Form of energy TRANSFERED DURING HEATING/COOLING - Keeps the Earth's surface warm - CANNOT provide organisms with energy to grow & function - #### Light Energy - VISIBLE forms of radiant energy - Can be used by some organisms (CANNOT be stored) - #### Chemical Energy - Used by living organisms to perform functions (growth, reproduction, etc.) - MUST be replaced as it is used ### Photosynthesis - Plants use the sun to make energy in the form of glucose or sugar. - Animals cannot make their own food (glucose, energy) - Must get our food from plants. - Plants are the first step in the food chain - Oxygen released during photosynthesis is necessary for all living things ### Cellular Respiration - Process of converting sugar into carbon dioxide, water and energy - Makes stored energy available for use, Takes place in the mitochondria 1. Original energy stored in the sugar is released 2. Occurs continuously 3. Does NOT require light energy - **BOTH** producers **AND** consumers perform cellular respiration - ALL humans are consumers (unless you’re the hulk) #### Steps in Cellular Respiration - Mitochondria takes in nutrients - Glucose and Oxygen - Breaks both nutrients down - Creates energy for the cell - #### REVERSE of Photosynthesis - Sugar breaks down into **CARBON DIOXIDE** and **WATER** - Release of energy when this happens ## Feeding Relationships - Energy flow through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various hetrotrophs (consumers). - Food are a series of steps in which organisms transfers energy by eating or eaten (pg. 43). - Food webs show the complex interactions within an ecosystem (pg. 44). - Each step in a food chain or web is called a `trophic` level. Producers make up the first step, consumers make up the higher levels. E.g. first trophic level are producers, second trophic level are primary consumers, etc. - Detrivores + scavengers are off to side (with all arrows pointing on it. - **First Trophic Level**: `Plants`. - `10% rule`, Only 10% of energy is stored in each organism, 90% of energy is lost (heat consumption). ## Ecological Pyramids - Food chains and food webs do not give any information about the numbers of organisms involved. - This information can be shown through ecological pyramids. - An ecological pyramid is a diagram that shows the amount of energy or matter contained within each trophic level in a food web or food chain. |Pyramid|Description|Picture| |:------|:----------|:------| |Pyramid of Biomass|Show the **total** amout of `living tissue` available at each `trophic` level. This shows the amount of tissue available for the next `trophic` level.

Biomass is preferred to the use of numbers of organisms because individual organisms can vary in size. It is the `total mass` **(not the size)** that is important. Sometimes it’s inverted.

Pyramid of biomass records the total dry organic matter of organisms at each trophic level in a given area of an ecosystem.| |Numbers Pyramids|Shows the number of organisms at each trophic level per unit area of an ecosystem.

Because each trophic level harvests only about `one tenth` of the energy from the level below, it can support only about one `10th` the amount of living tissue.

**`Can be inverted`**: 1 large tree supports thousands of organisms living on it

Pyramid of numbers displays the number of individuals annualy.|| |Energy Pyramid|Shows the amount of energy input to each trophic level in a given area of an ecosystem over an extended period.

**CANNOT** be inverted, due to energy transfers

**Only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.**|| **NOTE FOR ENERGY PYRAMIDS**: In nature, ecological efficiency varies from `5%` to `20%` energy available between successive trophic levels (`95%` to `80%` loss). About 10% efficiency is a general rule. `Rule of 10’s` at each level. ## Cycles |Cycle|Picture| |:----|:------| |Water Cycle|| |Carbon Cycle|| |Nitrogen Cycle|| ## Water Cycle - Continuous movement of water on, above and below the surface of the Earth ### Key Terms: - Water moves from one reservoir to another (ocean to atmosphere, river to lake) - Evaporation, Condensation, Precipitation, Percolation (Infiltration, water seeping into ground), Run-off, transpiration (plants losing water to air) - Forms: Solid (ice), Liquid (water), Gas (vapour) ### STEPS/PROCESS: - Exchange of energy leads to: - Temperature Change, Climate - Condenses 🡪 occurs during cooler temp - Evaporation 🡪 happens during warmer temp - **Evaporation**: - purifies the water - New fresh water for the land - **Flow of liquid water and ice** - Transports minerals across the globe - **Reshaping the geological features of Earth** - Erosion and sedimentation ### Human Inpacts - Humans building dams (flooding is a problem!) - Deforestation contributes to global warming, hence melting glaciers and causing flooding in cities - (Also less transpiration from clear cutting) – pg. 48 - Factories and cars pollute the air, leading to acid precipitation - Oil spills destroy aquatic ecosystems ## Carbon Cycle - Fourth most abundant element in universe - Building block of all living things - Main Pathway – in and out of living matter ### STEPS/PROCESSES - All living organisms contain carbon. - CO2 is a waste product of cellular respiration - Plants use carbon dioxide and water to form simple sugars (photosynthesis) - Light Energy --> Chemical Energy - Carbon dioxide is `returned to the enviornment by: 1. `Resipiration` in plants, animals & micro-organisms. 2. `Decay` caused by micro-organisms (decompoers). 3. `Combustion` i.e. Burning fossil fuels. - **Phtosynthesis** - CO2 is converted to glucose using water and sunlight - **Cellular Respiration** - Breaks down glucose to release energy, expel CO2 - **Oceans are a HUGE carbon sink**. ### Human Impacts - **Mining & burning fossil fuels**: Speed up release of CO2 to the atmosphere. - **Deforestation & clearing vegetation**: ↑ CO2 in atmosphere. - **Acid rain**: release CO2 from limestone. - CO2 in the atmosphere is now higher than it has been in at least **800 000 years**. ## Nitrogen Cycle - The most abudant gas in the atmopshere (~78%) - `Nitrogen Fixation`: The process that causes the strong two-atom nitrogen molecules found in the atmopshere to break apart so they can combine with other atoms. - `Nitrogen gets fixed`: Whenit is combined with oxygen or hydrogen. - An essential component of DNA, RNA, and protenis - the building blocks of life. - Atmopspheric nitrogen = N2 - Most living organisms are `unable` to use this form of nitrogen - Therefore, must be **converted** to a usable form! ### STEPS/PROCESSES ### Nitrogen Fixation - Most of the nitrogen used by living things is taken from the atmosphere by certain bacteria in a process called `nitrogen fixation`. - These microorganisms convert nitrogen gas into a variety of nitrogen containing compounds such as nitrates, nitrites, and ammonia - Lightning and UV radiation also fix small amounts of it - Humans add nitrogen to soil through fertilizer - 3 ways nitrogen to get fixed 1. Atmopheric Fixation - Lightning Storms - stroms and fuel burning in car engines produce nitrates, which are washed by rain into soil water. 2. Industrial Fixation 3. Biological Fixation - 2 types 1. Free living Bacteria - Highly specialized bacteria live in the soil and have the ability to combine atmospheric nitrogen with hydrogen to make ammonium(NH4+). - Nitrogen changes into ammonium. 2. Symbiotic Relationship Bacteria - Bacteria live in the roots of legume family plants and provide the plants with ammonium(NH4+) in exchange for the plant's carbon and a protected biome. - `Nitrites` are absorbed by plant roots and converted to plant protein. - `Nitrates` **can be absorbed by other plants** to continue the cycle. - `Denitrifying bacteria` convert soil nitrates into N2 gas - This is a `loss` of N2 from the cycle ### Human Impacts - Nitrates also `enters` the cycle **through the addition of nitrogen rich fertilizers to the soil** – made industrially from nitrogen gas (Eutrophication – pg. 60) - Factories release NO compounds (acid rain) ## Changes In Population - The carry capcacity of an ecosystem depends on numerous biotic and abiotic factors. - These can be classified into two categories. 1. `Density dependent factors` 2. `Density independent factors` ### Density Independent Factors - DIF’s can affect a population no matter what its density is. The effect of the factor (such as weather) on the size of the population **does not** depend on the **original size** of the population. - Examples: - unusual weather - natural disasters - seasonal cycles - certain human activities—such as damming rivers and clear-cutting forests ### Density Dependent Factors - DDF’s affect a population **ONLY** when it reaches a certain size. The effect of the factor (such as disease) on the size of the population depends on the **original size** of the population - Examples: - Competition - Predation - Parasitism - Disease ## Relationships 1. **Symbiosis** - Two different organisms associate with each other in a close way. - Is the interaction between members of `two different species` that live together in a close association. - **Mutualism (+/+)** - Both species benefit from the relationship. - (eg. human intestine and good bacteria, bees and flowers, clownfish and sea anemone, cattle egret and cow). - **Commensalism (+/0)** - one species benefits, the other is **unaffected**. - (eg. beaver cutting down trees, whales and barancles). - **Parasitism (-/+)** - one species is harmed, the other **benefits**. - (eg. lice and humans, mosquito and humans). - **Competition (-/-)** - neither species benefits. Can be harmed. (-/-). - **Neutralism (0/0)** - both species are unaffected (unlikely). - True neutralism is extremely unlikely or even impossible to prove. One cannot assert positively that there is absolutely no competition between or benefit to either species. - Example: fish and dandelion
+ Parasitism and Predation Commensalism Mutalism
0 Neutralism Commensalism
- Competition Parasitism and Predation
- 0 +
2. **Competition** - Individuals compete for limited resources - Types - **Intraspecific Competition** - Is the competition between individuals of the **same** species. - (eg. male deer uses antlers to fight each other for mates, little herons compete for food). - **Interspecific Competition** - Is the competition between individuals of **different** species. - (eg. cardinals and blue jays at a bird feeder, lions and hyenas competing for food). 3. **Predation** - One animal eats (kills) another. - Like a eagle eating a mouse or something. ### Reasons To Compete - Food and water. - Space (habitat). - Mates. ## Candian Biomes ### Tundra * Most **NORTHERN** biome of Canada. * Low temperatures + lots of **PERMAFROST** * Low decomposition rate. * Plants grow slower due to cold * `Species`: Polar bears, Caribou, Arctic foxes. ### Boreal Forest * **Largest** biome in Canada. * Warmer weather+plenty rainfall. * Acidic Soil - Limits variety of plants + slows down decomposition. * `Species` Grey wolves, conifers, moss, black bears. ### Grassland * Moderate rainfall (supports grass not trees). * Dry $`\rightarrow`$ Fire $`\rightarrow`$ Fire prevents larges trees from growing. * Very **Fertile** black soil (high decomposition rate) * Large portions of this biome are replaced by farms in Canada. * `Species`: Bison, Snakes, fescue grasses, voles. ### Temperate Deciduous Forest * Layers of canopy trees, understorey trees, shrubs, ground vegetation. * Variety oof plants + species. * Fast decomposition rate (warm temperatures). * Large portions of this biome used by humans for cities. * `Species`: Shrews, decidious trees, deer, black bears. ### Mountain Forest * Temperatures vary with elevation * Windy + cool summers * Heavy precipitation on leeward side of mountains * `Species` Elk, cougar, large coniferous trees, ferns. ## Introducing Ecosystems - Most ecosystems are **SUSTAINABLE**. ### Ecosystem Services/Products - **Cultural Services** - Benefits relating to our enjoyment of the environment. - Ex. Recreational, aesthetic and spiritual experiences when we interact with natural surroundings. - Ecotourism: tourists engage in environmentally responsible travel to relatively undisturbed natural areas. - Ex. Canada’s Wilderness. - **Ecosystem Products** - Humans use products produced by the ecosystem. - Hunt animals and harvest plants, lakes/oceans supply us with seafood. - **Terrestrial:** ecosystems: medicines, fibres, rubber and dyes. - **Forestry**: largest industries and employers. - **Regulate** and **maintain** important **abiotic** and **biotic** features of environment. - Cycle water, oxygen, and nutrients. - Help protect us from physical threats. - Plant communities protect the soil from wind and water erosion. - Ecosystems act as sponges. - Absorb water and slowly release it into the groundwater and surface water (reduces erosion and protects against flooding, filters the water). - Protect land from storms along coasts where wave damage erodes the shoreline. - Mangroves. ### Invasive Species - Introduction usually fails because few species can tolerate an entirely new environment. - Can adapt to abiotic environment, may have difficulty finding food/cant deal with competition. #### Impacts - **Ecological** - Competition, food, alter nutrient cycles. - **Economic** - Damage forests/crops = financial loss, diseases/pests destroy crops, trees and livestock. - **Tourism** - Species loss and reduced water quality = poor wildlife viewing, fishing and water based activities. - Waterways choked with invasive aquatic plants = no boats. - **Health** - Cause disease (west nile), pesticides used for control cause pollution and are health risks. #### Controlling Measures 1. **Chemical Control** - Most widely used = pesticides. - Used on forest/agricultural pests. - Pesticides dramatically reduce crop damage. - Environmental Risks. - May kill non-target native species/pollute air, water, soil. 2. **Mechanical Control** - Physical barriers or removal (cut down, burned, hunted). - Ex. Hamilton Harbour barrier to prevent Carp invasion. 3. **Biological Control** - Challenging but effective. - Uses intentionally introduced organisms to control the invasive species. - Ex. 3 insect species released in Ontario to control purple loosestrife (invasive plant that grows in wetlands). - Tests indicated the insects are unlikely to feed on native plants. - Rarely eradicates an invasive species … may reduce population sizes to tolerable levels. ### Engineered Ecosystems - Leaching happens in agroecosystems, where nitrogen rich water from fertilizers seep into the soil. This causes nutrients to dissolve in water and seep out of the soil. Increase growth of algae, (think eurotrophication). ### Pesticides - Pesticides can easily flow through food chains as there are not easily excreted, like DDT. There are fat-solutable. - DDT can be passed through organisms, from generation to generation, as the food we eat contains small amounts of DDT, and thus, the cycles continues. It doesn't matter how many generations ahead you are, everyone in the world contains some amount of DDT in their bodies.