Biology MTEL (Populations, Ecosystems, and the Environment)
Describe a community within the biosphere, including interspecific and intraspecific interactions.
A community is all of the populations of different species that live in an area and interact with each other. Community interaction can be intraspecific or interspecific. Intraspecific interactions occur between members of the same species. Interspecific interactions occur between members of different species. Different types of interactions include competition, predation, and symbiosis. Communities with high diversity are more complex and more stable than communities with low diversity. The level of diversity can be seen in a ood web of the community, which shows all the feeding relationships within the community. (intraspecific - same species; interspecific - different species)
Describe the natural disturbances that affect an ecosystem.
A natural disturbance is an event caused by nature, not human activity. Natural disturbances can be brought on by weather such as fires from lightning, droughts, storms, wind, and freezing. Other natural disturbances include earthquakes, volcanic eruptions, and diseases. Natural disturbances can disrupt or disturb the ecosystem in many ways such as altering resources or removing individuals from the community. Natural disturbances can cover small regions, or they can affect an entire ecosystem. The effect may be long lasting and take several years to recover, or the effect may be minor and take only a few months to recover.
Describe a population within the biosphere.
A population is a group of all the individuals of one species in a specific area or region at a certain time. A species is a group of organisms that can breed and produce fertile offspring. There may be many populations of a specific species in a large geographic region. Ecologists study the size, density, and growth rate of populations to determine their stability. The population density is the number of individuals per unit area. Growth rates may be exponential or logistic. Population size continuously changes with births, deaths, and migrations. Ecologists also study how the individuals are dispersed within a population. Some species form clusters. Others are evenly or randomly spaced. Every population has limiting factors. Changes in the environment can reduce population size. Geography can limit population size. The individuals of a population react with each other and with other organisms in the community. Competition and predation affect population size.
Describe altruistic behaviors between animals. Give examples. (Visit mometrix.com/academy for a related video. Enter video code: 757249)
Altruism is a self-sacrificing behavior in which an individual animal may serve or protect another animal. For example, in a honey bee colony, there is one queen, many workers (females), and drones (males) only during the mating seasons. Adult workers do all the work of the hive and will die defending it. Another example of altruism is seen in a naked mole rat colony. Each colony has one queen that mates with a few males, and the rest of the colony is nonbreeding and lives to service the queen, her mates, and her offspring.
Describe ecosystems within the biosphere.
An ecosystem is the basic unit of ecology. An ecosystem is the sum of all the biotic and abiotic factors in an area. Biotic factors are all living things, such as plants, animals, fungi, and microorganisms. Abiotic factors include the light, water, air, temperature, and soil in an area. Ecosystems obtain the energy they need from sunlight. Ecosystems contain biogeochemical cycles such as the hydrologic cycle and the nitrogen cycle. Ecosystems are generally classified as either terrestrial or aquatic. All of the things within an ecosystem are called its community. The number and variety of living things within a community describes the ecosystem's biodiversity. Each ecosystem can only support a limited number of organisms known as the carrying capacity.
Describe the general categories of aquatic biomes and give examples.
Aquatic biomes are characterized by multiple factors including the temperature of the water, the amount of dissolved solids in the water, the availability of light, the depth of the water, and the material at the bottom of the biome. Aquatic biomes are classified as marine regions or freshwater biomes based on the amount of dissolved salt in the water. Marine biomes include the pelagic zone, the benthic zone, coral reefs, and estuaries. Marine biomes have a salinity of at least 35 parts per thousand. (temperature, salinity, light, depth) Freshwater biomes include lakes, ponds, rivers, and streams. Freshwater biomes have a salinity that is less than 0.5 parts per thousand. Lakes and ponds, which are relatively stationary, consist of two zones: the littoral zone and the limnetic zone. The littoral zone is closest to the shore and is home to many plants (floating and rooted), invertebrates, crustaceans, amphibians, and fish. The limnetic zone is further from the shore and has no rooted plants. Rivers and streams typically originate in the mountains and make their way to the oceans. Because this water is running and colder, it contains different plants and animals than lakes and ponds. Salmon, trout, crayfish, plants, and algae are found in rivers and streams.
Explain competition and territorality. Give an example.
Competition is a relationship between two organisms in which the organisms compete for the same vital resource that is in short supply. Typically, both organisms are harmed, but one is usually harmed more than the other. They could be competing for resources such as food, water, mates, and space. Interspecific competition is between members of different species. Intraspecific competition is between members of the same species. Competition provides an avenue for natural selection. Territoriality can be considered to be a type of interspecific competition for space. Many animals including mammals, birds, reptiles, fish, spiders, and insects have exhibited territorial behavior. Once territories are established, there are fewer conflicts between organisms. For example, a male redwing blackbird can establish a large territory. By singing and flashing his red patches, he is able to warn other males to avoid his territory, and they can avoid fighting.
Describe how competition and predation influence a population size.
Feeding relationships between organisms can affect population size. Competition and predation both tend to limit population size. Competition occurs when two individuals need the same resource. Predation occurs when one individual is the resource for another individual. Competition occurs when individuals share a resource in the habitat. This competition can be intraspecific, which is between members of the same species, or interspecific, which is between members of different species. Intraspecific competition reduces resources as that species' own population increases. This limits population growth. Interspecific competition reduces resources as a different species uses those same resources. Predation occurs when one species is a food resource for another species. Predator and prey populations can cycle over a range of years. If prey resources increase, predator numbers increase. An example of the predator-prey population cycle is the Canadian lynx and the snowshoe hare.
Describe how resource availability and abiotic factors influence population size.
Population size is affected by resource availability and abiotic factors. As the population density increases, intraspecific competition for available resources itensifies. If the availability of resources decreases, death rates may increase and birth rates may decrease. For example, territoriality for mating or nesting may limit available resources for individuals in a population and limit the population size. Abiotic factors such as temperature, rainfall, wind, and light intensity all influence the population size. For example, temperatures near a species' tolerance limit may decrease the population. Natural disasters such as fire or flood can destroy and greatly decrease a population's size. In general, any abiotic factor that reduces or limits resources will also reduce or limit population size.
Describe the exponential population growth model.
Populations change over time due to births, deaths, and migrations. Sometimes, conditions are near ideal and populations can increase at their maximum rate exhibiting exponential growth. Exponential growth is growth in which the rate of change is proportional to the increasing size in an exponential progression. Exponential growth graphs as a J-shaped curve. Exponential growth is often observed in single-celled organisms such as bacteria or protozoa in which the population or number of cells increases by a factor of two per unit of time. One cell divides into two cells, which divide into four cells, and so forth. The exponential growth model describes population growth under ideal conditions. It does not take limiting factors or carrying capacity into account. Realistically, exponential growth cannot occur indefinitely, but it may occur for a period of time. It does show a species' capacity for increase and may be helpful when studying a particular species or ecosystem. For example, if a species with no natural predator is introduced into a new habitat, that species may experience exponential growth. If this growth is allowed to go unchecked, the population may overshoot the carrying capacity and then starve. Efforts may need to be taken to reduce the population before this occurs.
Describe the logistic population growth model.
Populations vary over time due to deaths, births, immigration, and emigration. In most situations, resources such as food, water, and shelter are limited. Each environment or habitat can only support a limited number of individuals. This is known as the carrying capacity. Population growth models that factor in the carrying capacity are called logistic growth models. With logistic population growth models, the rate of population growth decreases as the population size increases. Logistic growth graphs as an S-shaped curve. Comparing logistic growth and exponential growth shows that the graph for exponential growth continues to become steeper, but the graph for logistics growth levels off once the population reaches the carrying capacity. As the population increases, fewer resources are available per individual. This limits the number of individuals that can occupy that environment or habitat.
Explain predation. Give examples
Predation is a special nutritional relationship in which one organism is the predator, and the other organism is the prey. The predator benefits from the relationship, but the prey is harmed. The predator hunts and kills the prey for food. The predator is specially adapted to hunt its prey, and the prey is specially adapted to escape its predator. While predators harm (kill) their individual prey, predation usually helps the prey species. Predation keeps the population of the prey species under control and prevents them from overshooting the carrying capacity, which often leads to starvation. Also, predation usually helps to remove weak or slow members of the prey species leaving the healthier, stronger, and better adapted individuals to reproduce. Examples of predator-prey relationships include lions and zebras, snakes and rats, and hawks and rabbits.
Describe the impact of resource management such as waste management and recycling on the environment.
Resource management such as waste management and recycling greatly impacts the environment. Waste management is the monitoring, collection, transportation, and recycling of waste products. Well-managed landfills include using clay or another lining material to prevent liquid leachate and layers of soil on top to reduce odors and vermin. Wastes can be incinerated to reduce waste volume. Hazardous biomedical waste can be incinerated. However, incineration does emit pollutants and greenhouse gases. Proper waste management always includes recycling. Recycling is a method to recover resources. Recycles materials can be reprocessed into new products. Metals such as aluminum, copper, and steel are recycled. Plastics, glass, and paper products can be recycled. Organic materials such as plant materials and food scraps can be composted. The current trend is to shift from waste management to resource recovery. Wastes should be minimized and reduced to minimize the need for disposal. Unavoidable nonrecyclable wastes should be converted to energy by combustion if at all possible.
Describe terrestrial biomes, and give several examples.
Terrestrial biomes are classified predominantly by their vegetation, which is primarily determined by precipitation and temperature. Tropical rainforests experience the highest annual precipitation and relatively high temperatures. The dominant vegetation in tropical forests is tall evergreen trees. Temperate deciduous forests experience moderate precipitation and temperatures. The dominant vegetation is deciduous trees. Boreal forests experience moderate precipitation and lower temperatures. The dominant vegetation is coniferous trees. The tundra experiences lower precipitation and cold temperatures. The dominant vegetation is shrubs. The savanna experiences lower precipitation and high temperatures. The dominant vegetation is grasses. Deserts experience the lowest precipitation and the hottest temperatures. The dominant vegetation is scattered thorny plants.
Describe the impact of the Endangered Species Act.
The Endangered Species Act (ESA) of 1973 has had a positive impact on many species. The law was designed to protect "imperiled species" from extinction due to factors such as loss of habitat, overhunting, and lack of conservation. The ESA also protects the species' ecosystems and removes threats to those ecosystems. If an animal is placed on the endangered or threatened list, it is prohibited to "harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct" with the endangered animal. The populations of many species have increased significantly, including the whooping crane, the gray wolf, the red wolf, and the Hawaiian goose. Some species have even been removed from the endangered species list, including the bald eagle, the peregrine falcon, the gray whale, and the grizzly bear. The ESA has protected numerous species while balancing human economic needs and rights to private property.
Define biome, and list several types of biomes.
The biosphere consists of numerous biomes. A biome is a large region that supports a specific community. Each biome has a characteristic climate and geography. Differences in latitude, altitude, and worldwide patterns affect temperature, precipitation, and humidity. Biomes can be classified as terrestrial or aquatic biomes. Terrestrial biomes include ecosystems with land environments, such as tundra, coniferous forest, temperate broadleaf forest, temperate grassland, chaparral, desert, savannas, and tropical forests. Terrestrial biomes tend to grade into each other in regions called ectotones. Aquatic biomes are water-dwelling ecosystems. Aquatic biomes include lakes, coral reefs, rivers, oceanic pelagic zone, estuaries, intertidal zone, and the abyssal zone.
List and describe the components of the biosphere.
The biosphere is the region of the earth inhabited by living things. The components of the biosphere from smallest to largest are organisms, populations, communities, ecosystems, and biomes. Organisms of the same species make up a population. All of the populations in an area make up the community. The community combined with the physical environment for a region forms an ecosystem. Several ecosystems are grouped together to form large geographic regions called biomes. (1. organisms 2. populations - organisms of the same species 3. communities - all populations in an are 4. ecosystems - abiotic and biotic factors 5. biomes - several ecosystems)
Sketch and describe the carbon cycle.
The carbon cycle is a biogeochemical cycle that describes the continuous movement of the Earth's carbon. Carbon is in the atmosphere, the soil, living organisms, fossil fuels, oceans, and freshwater systems. These areas are referred to as carbon reservoirs. Carbon flows between these reservoirs in an exchange called the carbon cycle. In the atmosphere, carbon is in the form of carbon dioxide. Carbon moves from the atmosphere to plants through the process of photosynthesis. Carbon moves from plants to animals through food chains. Carbon moves from living organisms to the soil when these organisms die. Carbon moves from living organisms to the atmosphere through cellular respiration. Carbon moves from fossil fuels to the atmosphere when fossil fuels are burned. Carbon moves from the atmosphere to the oceans and freshwater systems through absorption.
Describe the impact of the extraction of minerals and oil drilling on the environment.
The extraction of mineral and energy resources by mining and drilling has harmful effects on the environment including pollution and alterations to ecosystems. Mining requires large amounts of land, which harms habitats and affects biodiversity. Mining causes water pollution. Rainwater mixes with the heavy metals in mines and produces an acid runoff that harms aquatic life, birds, and mammals. The pollution is especially bad in countries without proper mining regulations. Open-pit mines and mountaintop removal techniques are especially harsh to the environment, and reclamation is often not regulated in developing countries. Mining often requires large-scale deforestation leading to a loss of habitat for many species. Toxic chemicals such as mercury and sulfuric acid are used in the mining process and are released into bodies of water, harming the aquatic life. If these toxic chemicals are leaked, the ground water is polluted. Oil drilling is controversial due to habitat disruption or loss. Oil spills are toxic to wildlife and difficult to clean up. Offshore drilling uses seismic waves to locate oil, which disturbs whales and dolphins and has been tied to hundreds of beached whales.
Describe the significance of habitat and niche to a population.
The habitat of an organism is the type of place where an organism usually lives. A habitat is a piece of an environmental area. A habitat may be a geographic area or even the body of another organism. The habitat describes an organism's natural living environment. A habitat includes biotic and abiotic factors such as temperature, light, food resources, and predators. Whereas a habitat describes an organism's "home," a niche can be thought of as an organism's "occupation." A niche describes an organism's functional role in the community and how the organism uses its habitat. A niche can be quite complex because it should include the impacts that the organism has on the biotic and abiotic surroundings. Niches can be broad or narrow. habitat - where an organism lives (biotic & abiotic factors) niche - an organism's job
Describe the advantages and disadvantages of asexual reproduction in animals.
Very few species of animals reproduce by asexual reproduction, and nearly all of those species also have the ability to reproduce sexually. While not common, asexual reproduction is useful for animals that tend to stay in one place and may not find mates. Asexual reproduction takes considerably less effort and energy than sexual reproduction. In asexual reproduction, all of the offspring are genetically identical to the parent. This can be a disadvantage because of the lack of genetic variation. Although asexual reproduction is advantageous in a stable environment, if the environment changes, the organisms may lack the genetic variability to survive or selectively adapt.
Describe the changes that occur during primary and secondary succession.
Ecological succession is the process by which climax communities come into existence or are replaced by new climax communities when they are greatly changed or destroyed. The two types of ecological succession are primary succession and secondary succession. Primary succession occurs in a region where there is no soil and that has never been populated such as a new volcanic island or a region where a glacier has retreated. During the pioneer stage, the progression of species is typically lichen and algae, followed by small annual plants, then perennial herbs and grasses. During the intermediate stage, shrubs, grasses, and shade-intolerant trees are dominant. Finally, after hundreds of years, a climax community is reached with shade-tolerant trees. Secondary succession occurs when a climax community is destroyed or nearly destroyed such as after a forest fire or in an abandoned field. With secondary succession, the area starts with soil and seeds from the original climax community. Typically, in the first two years, weeds and annuals are dominant. This is followed by grasses and biennials. In a few years, shrubs and perennials are dominant followed by pine trees, which are eventually replaced by the deciduous trees. Secondary succession takes place in less than 100 years.
Describe energy flow in the environment using a food web. (Visit mometrix.com/academy for a related video. Enter video code: 853254)
Energy flow through an ecosystem can be illustrated by a food web. Energy moves through the food web in the direction of the arrows. In the food web below, producers such as grass, trees, and shrubs use energy from the sun to produce food through photosynthesis. Herbivores or primary consumers such as squirrels, grasshoppers, and rabbits obtain energy by eating the producers. Secondary consumers, which are carnivores such as snakes and shrews, obtain energy by eating the primary consumers. Tertiary consumers, which are carnivores such as hawks and mountain lions, obtain energy by eating the secondary consumers. Note that the hawk and the mountain lion can also be considered quaternary consumers in this food web if a different food chain within the web is followed. sun -> plants -> primary consumers -> secondary consumers -> tertiary consumers
Describe energy flow in the environment using trophic levels with an energy pyramid.
Energy flow through an ecosystem can be tracked through an energy pyramid. An energy pyramid shows how energy is transferred from one trophic level to another. Producers always form the base of an energy pyramid, and the consumers form successive levels above the producers. Producers only store about 1% of the solar energy they receive. Then, each successive level only uses 10% of the energy of the previous level. In this energy pyramid, grass, which is a producer, uses 1,000 kcal of energy. Then the grasshoppers, which are primary consumers, use 10% of that 1,000 kcal or 100 kcal. Next, the moles, which are secondary consumers, use 10% of that 100 kcal or 10 kcal. Finally, the owl, which is a tertiary consumer, uses 10% of that 10 kcal or 1 kcal of energy. (90% of energy is released as heat at each trophic level)
What are some examples of renewable and nonrenewable energy resources? What are some advantages and disadvantages of each?
Energy sources such as wind, solar power, and biomass energy are all renewable. Wind power is clean with no pollution and no greenhouse gas emissions. Disadvantages of wind power include the use of land for wind farms, threats to birds, and the expense to build. Solar power has no greenhouse gas emissions, but some toxic metal wastes result in the production of photovoltaic cells, and solar power requires large areas of land. Biomass energy is sustainable, but its combustion produces greenhouse emissions. Farming biomass requires large areas of land. Fossil fuels, which are nonrenewable, cause substantially more air pollution and greenhouse gas emissions, contributing to habitat loss and global warming. renewable - wind, solar power, biomass energy nonrenewable - fossil fuels
List several biotic and abiotic factors in an ecosystem.
Every ecosystem consists of multiple abiotic and biotic factors. Abiotic factors are the nonbiological physical and chemical factors that affect the ecosystem. Abiotic factors include soil type, atmospheric conditions, sunlight, water, wind, chemical elements, and natural disturbances. In aquatic ecosystems, abiotic factor include salinity, turbidity, water depth, current, temperature, and light. Biotic factor are all of the living organisms in the ecyosystem. Biotic factors include plants, algae, fungi, bacteria, archaea, animals, and protozoa.
Sketch and describe the water cycle.
The water cycle, also referred to as the hydrologic cycle, is a biogeochemical cycle that describes the continuous movement of the Earth's water. Water in the form of precipitation such as rain or snow moves from the atmosphere to the ground. The water is collected in oceans, lakes, rivers, and other bodies of water. Heat from the sun causes water to evaporate from oceans, lakes, rivers, and other bodies of water. As plants transpire, this water also undergoes evaporation. This water vapor collects in the sky and forms clouds. As the water vapor in the clouds cools, the water vapor condenses or sublimes depending on the conditions. Then, water moves back to the ground in the form of precipitation.
Describe the impact of global warming, rising sea levels, and flooding on society.
Global warming caused largely by greenhouse gas emission will greatly affect society in the next several years. The increase in global temperature leads to more extreme weather events such as hurricanes, tornadoes, floods, and droughts. Rising temperatures mean warmer summers. Warmer temperatures may shift tourism and improve agriculture, but global mortality rates may rise due to hotter heat waves. Rising temperatures cause weather patterns to shift, leading to more floods and droughts. Rising temperatures mean a decrease in glaciers, sea ice, ice sheets, and snow cover, which all contribute to rising sea levels. Rising sea levels lead to habitat change or loss, which greatly affects numerous species. Some motile species are already moving north to cooler climates. Earlier snowmelt and runoff may overwhelm water management systems. Diseases such as malaria that are spread by mosquitoes could spread further, possibly even to temperate regions. Rising sea levels mean higher storm surges and related issues. (more extreme weather events, warmer temperature, increase in global mortality rates, habitat loss, spread of diseases)
Describe the effect of the fragmentation of ecosystems on biodiversity.
Habitats can become fragmented due to natural disturbances such as fire, volcanic activity, and climate change. Some of the original habitat is destroyed during fragmentation, reducing the total area of the habitat. As a result, there may be insufficient food or other resources to support a species. The resulting habitats may also be reproductively isolated from each other, thus limiting genetic variation and biodiversity. Small fluctuations in resources or climate can be catastrophic in small populations. Larger populations may be able to overcome these fluctuations in variation. (fragmentation - process of being broken into smaller parts)
Explain how human population affects ecological systems and biodiversity.
Human population has been increasing at a near-exponential rate for the past 50 years. As the human population increases, the demand for resources such as food, water, land, and energy also increases. As the human population increases, the number of species decreases due to habitat destruction, introduced species, and overhunting The increased greenhouse gases and resulting climate changes have also significantly affected many ecosystems as temperatures rise and habitats are slowly changed or even destroyed. Increasing human population means increasing pollution, which harms habitats. Many animals have become extinct due to the effects of an exponentially increasing human population. High rates of extinction greatly reduce biodiversity. (the higher the population, the higher the demand for resources, the higher the amount of greenhouse gases, the lower the number of species, and the lower the number of habitats)
Define remediation and give two examples. Explain how these examples affect ecological systems and biodiversity.
In remediation, or land rehabilitation, environmental damages are reversed or stopped by attempting to restore land to its prior condition. Examples of remediation are reforestation and mine reclamation. Mining reclamation included the backfilling of open-pit mines and covering ores containing sulfides to prevent rain from mixing with them to produce sulfuric acid. Reforestation is the restocking of forests and wetlands. This can at least partially offset the damaging effects brought about by the deforestation. Reforestation can help reduce global warming due to an increase in the absorption of light by the trees. Restoration can also help to restore the carbon cycle and counter erosion. Reforestation can help maintain or preserve the biodiversity of the region and possibly increase biodiversity if new organisms immigrate into the region.
Explain how introduced species affect ecological systems and biodiversity. Give an example.
Introduced species are species that are moved into new geographic regions by humans. They are also called invasive or nonnative species. Introduction can be intentional, such as the introduction of livestock, or unintentional, such as the introduction of Dutch elm disease. Introduced species can disrupt their new communities by using limited resources and preying on other members of the community. Introduced species are often free from predators and can reproduce exponentially. This typically causes a decrease in biodiversity. Introduced species are contributors or even responsible for numerous extinctions. For example, zebra mussels, which are native to the Black Sea and the Caspian Sea, were accidentally introduced to the Great Lakes. The zebra mussels greatly reduced the amount of plankton available for the native mussel species, many of which are now endangered.
Explain how habitat destruction by humans affects ecological systems and biodiversity.
Many habitats have been altered or destroyed by humans. In fact, habitat destruction brought about by human endeavors has been the most significant cause of species extinctions resulting in the decrease in biodiversity throughout the world. As the human population has increased exponentially, the extinction rate has also increased exponentially. This is largely due to habitat destruction by humans. Humans use many resources in their various enterprises including agriculture, industry, mining, logging, and recreation. Humans have cleared much land for agriculture and urban development. As habitats are destroyed, species are either destroyed or displaced. Often, habitats are fragmented into smaller areas, which only allow for small populations that are under threat by predators, diseases, weather, and limited resources. Especially hard hit are areas near the coastline, estuaries, and coral reefs. Nearly half of all mangrove ecosystems have been destroyed by human activity. Coral reefs have nearly been decimated from pollution such as oil spills and exploitation from the aquarium fish market and coral market.
Explain symbiosis, including parasitism, commensalism, and mutualism. Give examples.
Many species share a special nutritional relationship with another species, called symbiosis. The term symbiosis means "living together." In symbiosis, two organisms share a close physical relationship that can be helpful, harmful, or neutral for each organism. Three forms of symbiosis are parasitism, commensalism, and mutualism. Parasitism is a relationship between two organisms in which one organism is the parasite, and the other organism is the host. The parasite benefits from the relationship because the parasite obtains its nutrition from the host. The host is harmed from the relationship because the parasite is using the host's energy and giving nothing in return. For example, a tick and a dog share a parasitic relationship in which the tick is the parasite, and the dog is the host. Commensalism is a relationship between two organisms in which one benefits, and the other is not affected. For example, a small fish called a remora can attach to the belly of a shark and ride along. The remora is safe under the shark, and the shark is not affected. Mutualism is a relationship between two organisms in which both organisms benefit. For example, a rhinoceros usualy can be seen with a few tick birds perched on its back. The tick birds are helped by the easy food source of ticks, and the rhino benefits from the tick removal. Parasitism +/- Commensalism +/0 Mutualism +/+
Describe the three areas of marine regions.
Marine regions are located in three broad areas: the ocean, estuaries, and coral reefs. The ocean consists of two general regions - the pelagic zone and the benthic zone. The pelagic zone is in the open ocean. Organisms in the pelagic zone include phytoplankton such as algae and bacteria; zooplankton such as protozoa and crustaceans; and larger animals such as squid, sharks, and whales. The benthic zone consists of the floor and the ocean floor. Organisms in the benthic zone consists of the floor and the ocean floor. Organisms in the benthic zone can include sponges, clams, oysters, starfish, sea anemones, sea urchins, worms, and fish. The deepest part of the benthic zone is called the abyssal plain. This is the deep ocean floor, which is home to numerous scavengers, many of which have light-generating capability. Estuaries are somewhat-enclosed coastal regions where water from rivers and streams is mixed with seawater. Coral reefs are located in warm, shallow water. Corals are small colonial animals that share a mutualistic relationship with algae.
Describe the impact of nonpoint sources of pollution on the environment.
Nonpoint-source pollution is the leading cause of water pollution in the United States. Nonpoint-source pollution is pollution that does not flow through a pipe, channel, or container. Most nonpoint-source pollution is due to agricultural runoff. Urban runoff from lawns, streets, and parking lots is also treated as nonpoint-source pollution because much of that storm water does not go into a storm drain before entering streams, rivers, lakes, or other bodies of water. Urban runoff contains chemicals such as lawn fertilizers, motor oils, grease, pesticides, soaps, and detergents, each of which is harmful to the environment.
Describe the impact of pollution mitigation and the Clean Air Act on the environment.
Pollution mitigation has greatly reduced pollution and its effect during the past 40 years. The Clean Air Act has reduced pollution by requiring that new industrial sites contain pollution-control technology. These technologies avoid or minimize the negative effects on the environment. For example, new coal-fired power plants are fitted with pollution-control devices that greatly reduce and nearly eliminate sulfur dioxide and nitrogen oxide emissions. This greatly reduces acid rain, improves water quality, and improves the overall health of ecosystems. Reducing acid rain improves soil quality, which in turn improves the health of consumers, essentially strengthening the entire ecosystem. Reduced greenhouse gas emissions have lessened the impact of global warming such as rising sea levels due to melting glaciers and the resulting loss of habitats and biodiversity. Reduced smog and haze improves the intensity of sunlight required for photosynthesis.
Describe life histories. Discuss the relationship between parental investment, number of offspring, and mortality rates.
The life history of a species describes the typical organism's life cycle from birth through reproduction to death. Life histories can typically be classified as opportunistic life histories or equilibrial life histories. Species exhibiting opportunistic life histories are typically small, short-lived organisms that have a high reproductive capacity but invest little time and care into their offspring. Their population sizes tend to oscillate significantly over periods of several years. Species exhibiting equilibrial life histories are typically large, long-lived organisms that have a low reproductive capacity but invest much time and care into their offspring. Their populations tend to fluctuate within a smaller range. A general observation is that species that tend to produce numerous offspring typically tend to invest little care into that offspring, resulting in a high mortality rate of that offspring. Organisms of species that tend to produce few offspring typically invest much more care into that offspring, resulting in a lower mortality rate. Opportunistic - small, short-lived organisms, high reproductive capacity, low parental involvement Equilibrial - large, long-lived organisms, lower reproductive capacity, high parental involvement
Describe sustainable agriculture and how it helps the environment.
The management of natural resources and the renewability or sustainability of those natural resources greatly impact society. Sustainable agriculture involves growing foods in economical ways that do not harm resources. If left unchecked, farming can deplete the soil of valuable nutrients. Crops grown in these depleted soils are less healthy and more susceptible to disease. Sustainable agriculture uses more effective pest control such as insect-resistant corn, which reduces runoff and water pollution in the surrounding area. Sustainable forestry involves replenishing trees as trees are being harvested, which maintains the environment.
Sketch and describe the nitrogen cycle.
The nitrogen cycle is a biogeochemical cycle that describes the continuous movement of the Earth's nitrogen. Approximately 78% of the Earth's atmosphere consists of nitrogen in its elemental form N2. Nitrogen is essential to the formation of proteins, but most organisms cannot use nitrogen in this form and require the nitrogen to be converted into some form of nitrates. Lightning can cause nitrates to form in the atmosphere, which can be carried to the soil by rain to be used by plants. Legumes have nitrogen-fixing bacteria in their roots, which convert the N2 to ammonia (NH3). Nitrifying bacteria in the soil can also convert ammonia into nitrates. Plants absorb nitrates from the soil, and animals can consume the plants and other animals for proteins. Denitrifying bacteria can convert unused nitrates back to nitrogen to be returned to the atmosphere. N2 in atmosphere -> nitrogen fixing bacteria convert to NH3 -> nitrifying bacteria convert to NO3 -> animals eat plants which absorb NO3 from soil -> denitrifying bacteria can convert unused NO3 to N2
Sketch and describe the phosphorus cycle.
The phosphorus cycle is a biogeochemical cycle that describes the continuous movement of the Earth's phosphorus. Phosphorus is found in rocks. When these rocks weather and erode, the phosphorus moves into the soil. The phosphorus found in the soil and rocks is in the form of phosphates or compounds with the PO4^3- ion. When it rains, phosphates can be dissolved into the water. Plants are able to use phosphates from the soil. Plants need phosphorus for growth and development. Phosphorus is also a component of DNA, RNA, ATP, cell membranes, and bones. Plants and algae can absorb phosphate ions from the water and convert them into many organic compounds. Animals can get phosphorus by eating food or drinking water. When organisms die, the phosphorus is returned to the soil. This is the slowest of all biogeochemical cycles.
Describe the impact of the establishment of the National Park System.
The purpose of the National Park System is to "conserve the scenery and the natural and historic objects and the wildlife therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations." The National Park System protects complete ecosystems and houses great biodiversity. National parks are an integral part of the survival of many species. National parks provide a home to hundreds of endangered or threatened species. Studies show that preserved habitats near national parks helps many species better survive. This will prevent fragmentation and further habitat loss. Nevertheless, National Parks may be threatened by invasion species or pressure for use of land along park boundaries. Also, biodiversity is threatened even within national parks. Although many are vast, they still may not be large enough to support a species population.
