Exam 4 Sci 1101

nitrogen cycle

-nitrification is a major flux in this cycle -this cycle's largest reservoir is the atmosphere

carbon cycle

-photosynthesis is a major flux in this cycle -this cycle is significantly affected by the extraction of fossil fuels

Dynamic Equilibrium

The state reached when processes within a system are moving in opposing directions at equivalent rates so that their effects balance out.

Homeostasis

The tendency of a system to maintain constant or stable internal conditions

Based upon what we are learning about the lionfish diet, what is most likely going to happen to Caribbean coral reefs invaded by lionfish?

There will be fewer algae-eating fish. More algae will grow over and damage corals. Sadly, the environmental damage of invasive species can be long lasting and unpredictable.

Pick the answer that best evaluates the following statement: "It has been said that land animals can't exist without plants but that plants could exist without animals."

This statement is true because plants are able to convert sun energy into food energy and animals must get their energy from plants or other organisms that eat plants. The sun's energy must be captured and is stored in the chemical bonds of foods made by plants. Animals are unable to capture the sun's energy as a food source and are therefore dependent on plants for their energy.

Zooplankton

Tiny aquatic animals that feed on phytoplankton and generally comprise the second trophic level in an aquatic food chain.

Which of the following statements best describes competition for a niche?

Two species could divide a niche through "resource partitioning." Resource partitioning is one way that two species can divide a shared niche.

Competitive Exclusion Principle

complete competitors cannot coexist

Detritus is composed of _____.

dead organic matter and excreted wastes Detritus is composed of dead organic matter and excreted wastes.

What name is given to the process by which detritivores return carbon to the atmosphere?

decomposition Decomposition, the conversion of organic molecules into inorganic molecules, results in the release of carbon dioxide into the atmosphere.

An earthworm that feeds on the remains of plants and animals is acting as a _____.

detritivore

Which best describes how energy and nutrients work in an ecosystem?

energy flows through an ecosystem; nutrients cycle. Energy is lost to the ecosystem as heat so it cannot be recycled. The planet is a closed system to nutrients; they must be recycled.

Nitrogen and phosphorus pollution of the Chesapeake Bay cause phytoplankton to increase, which ultimately leads to the process called __________.

eutrophication This is a process of nutrient pollution, blooms of algae, decomposition, and hypoxia that can lead to dead zones, like the one in the Gulf of Mexico.

Filter Feeding

feeding by filtering out plankton or nutrients suspended in the water.

Which of the following best characterizes the factors that have contributed to the "dead zone" in the waters of the Gulf of Mexico for at least the last decade?

fertilizer runoff from farms in the Mississippi River drainage. The nitrogen content of the water has increased so that bacterial activity has reduced oxygen levels dramatically.

Niche (fundamental niche)

functional role of a species in a community-everything relating to the lifestyle of an organism. Nutrients it requires, competitors, predators, prey, etc.

Community

group of interacting organisms in a given area. In ecology, an assemblage of populations of organisms that live in the same place at the same time.

Many plants have developed complicated defenses to protect themselves against _____.

herbivory When animals feed on the tissues of plants the plants have a more difficult time surviving to reproduce. They can develop elaborate defenses to deter their herbivores.

Generalist

A species that can survive in a wide array of habitats or use a wide array of resources.

Specialist

A species that can survive only in a narrow range of habitats that contain very specific resources.

phosphorus cycle

-this cycle is affected by the release of detergents in treated wastewater -the weathering of rock is a major flux in this cycle

water cycle

-transpiration is a major flux in this cycle -this cycle's larges reservoir is ocean water

Using "+" for those who benefit, "−" for those who are harmed, and "0" for no effect, which of the following expressions for the host species and other species (respectively) represents commensalism?

0 / + In commensalism, the host is unaffected and the other species is benefited. A good example is the commensal amoebae that live in the human intestine. They eat bacteria that we provide in extremely large numbers. We receive no known benefit from their association with us.

10,000 kcal of producer could support approximately _____ kcal of tertiary consumer.

10

Approximately _____% of the energy at one trophic level is passed on to the next highest trophic level.

5-10

Which statement is an accurate description of a keystone species?

A keystone species that is a predator controls the herbivore populations, which in turn maintains the plant populations and keeps balance. For example, removing wolves from Alaska would cause a population explosion of moose that would then depopulate the plants of the region. Hunting would then be the principal means of population control as is true of the eastern whitetail deer.

Ecotipping Point

A lever that reverses environmental decline, setting in motion restoration and sustainability.

System

A network of relationships among a group of parts, elements, or components that interact with and influence one another through the exchange of energy, matter, and/or information.

What characteristics of lionfish contribute to their ability to spread and become established in new areas?

A single lionfish female may produce up to 2 million eggs a year. The eggs float for up to a month, spreading the lionfish populations. As noted on the map in the video, lionfish populations have spread tremendously since the first population in South Florida in 1985. Lionfish are now widespread along the Atlantic, Caribbean, and northern coastlines of South America. All of this, in about 25 years!

Fundamental Niche

A species includes the total range of environmental conditions that are suitable for existence without the influence of interspecific competition or predation from other species.

Ecosystem

All organisms and nonliving entities that occur and interact in a particular area at the same time.

Ecosystem Service

An essential service an ecosystem provides that supports life and makes economic activity possible. For example, ecosystems naturally purify air and water, cycle nutrients, provide for plants to be pollinated by animals, and receive and recycle the waste we generate

How did the fish biologists determine the diet of lionfish in the regions where the lionfish have invaded?

Biologists examined the contents of the stomachs of lionfish caught in the wild. Investigating the stomach contents of fish and other aquatic vertebrates is a common way for biologists to learn about animal diets.

_____ are secondary consumers.

Carnivores Secondary consumers are animals that eat other animals; thus, they are carnivores.

The following answers for the Causes and Consequences features are examples and are not intended to represent a comprehensive list. In addition, the sequence of items is not meant to connote relative importance.

Causes: increased global transport and mobility; favorable conditions for invasives due to climate change. Consequences: decline of native organisms due to competition with invasives; economic costs for control and removal of invasives; change in community structure and function. Solutions: stricter policies aimed at ballast water dumping and other particulars; improved manual or chemical control measures.

Which of the following statements about dead zones is correct?

Dead zones are reversible if nutrient pollution input to a system is reduced. Examples of the reversal of hypoxic waters have been seen in New York City and the former Soviet Union.

Eutrophication

The process of nutrient enrichment, increased production of organic matter, and subsequent ecosystem degradation in a water body.

Emergence

How collective properties arise from the properties of parts, how behavior at a larger scale arises from the detailed structure, behavior and relationships at a finer scale.

Climax Community

In the traditional view of ecological succession, a community that remains in place with little modification until disturbance restarts the successful process. Today, ecologists recognize that community change is more variable and less predictable than originally thought and that assemblages of species may instead form complex mosaics in space and time.

Why do we classify lionfish populations near the eastern United States as an invasive species? What suggests that these new populations are not an expansion of the lionfish's natural range?

Lionfish are native to the tropical Pacific. There are no natural water routes of warm water between the Pacific and Atlantic oceans. The first isolated appearance of lionfish in South Florida waters also suggests that humans most likely introduced captive lionfish.

Phytoplankon

Microscopic photosynthetic algae, protists, and cyanobacteria that drift near the surface of water bodies and generally form first trophic level in aquatic food chains.

Which of the following is true of the hydrologic cycle?

Most of the water that falls on the continents is derived from the oceans. About 20% of the moisture evaporated from the ocean combines with 2% of land-derived moisture to produce 22% of all precipitation that falls over land. Clearly, the bulk of continental precipitation comes from the oceanic portion of the cycle.

Nitrogen availability is often a limiting factor in plant growth. Nitrogen tends to be scarce because __________.

Nitrogen gas (N2) is so stable that only a few organisms are capable of turning it into nitrogen that can be used for living things. Only a few types of bacteria are able to turn atmospheric nitrogen into biologically available nitrogen.

How does predation differ from parasitism?

Parasites rarely kill their host while predators kill their prey. Parasites often feed off one host for a prolonged period of time, so killing the host would be not serve the parasite's best interest.

Coevolution

Process by which two or more species evolve in response to one another. Parasites and hosts may evolve, as may flowering plants and their pollinators.

Niche

The functional role of a species in a community

When a species is moved from its native area to a new area, it can become an invasive species and damage its new ecosystem. What is one reason these species are able to do damage to an ecosystem?

When a species is transported, it leaves behind its predators and the diseases that previously kept its population in check. Therefore the species is able to grow to large and damaging numbers. The loss of limiting factors such as predators and diseases allows these invasive species to increase in number more than they would in their home range.

Realized Niche

Width is a phrase relating to ecology defining the actual space that an organism inhabits and the resources it can access as a result of limiting pressures from other species

Which of these is a starting point for primary succession?

a surface exposed by a retreating glacier Such a surface lacks any life and is thus a starting point for primary succession.

Which of these removes carbon from the atmosphere?

algae Photosynthetic organisms, such as algae, remove carbon from the atmosphere.

A(n) _____ is an example of an ecosystem with high primary productivity while a _____ is an example of an ecosystem with low primary productivity.

algal bed, desert An algal bed can convert solar energy to biomass energy very quickly and thus has high primary productivity while the desert organisms do not convert solar energy to biomass energy very quickly and therefore have low primary productivity.

Which of the following would have the largest biomass in a terrestrial ecosystem?

autotrophs A very large amount of producers, also called autotrophs, (in terms of sheer biomass) are required to produce enough food for all of the upper levels of consumers.

The changes to the cuttlefish's skin are related to _______.

camoflauge

Character Displacement

can result from competition acting as selective agent; genetic change (evolution) leading to change in phenotypes of competing species resulting in decreased competition. A phenomenon resulting from competition among species in which competing species evolve characteristics that better adapt them to specialize on the portion of the resource they use. The species essentially become more different from one another, reducing their competition.

Based upon what we are learning about invasive lionfish populations in the Caribbean and along the Atlantic coast of the United States, these lionfish populations __________.

cannot be eliminated by any means currently known Sadly, the environmental damage of invasive species can be long lasting and unpredictable.

What does the term emergent properties describe?

characteristics that are not evident in the system's individual components but are evident only by looking at the whole operating system. An emergent property of a tree is that it may be used by birds for building nests, something that is not apparent just by knowing the parts of a tree.

The largest percentage of fresh water today is located in:

ice sheets and glaciers. Ice sheets and glaciers are the greatest single repository of fresh water: they contain 77.3% of all Earth's fresh water and 99.357% of all Earth's surface fresh water.

Competition

interactions caused by a shared requirement for a limited resource

If two members of the same bird species are competing for the same tree to build a nest in, this is considered_____

intraspecific competition

The first colonizing organisms during primary succession tend to be:

lichens and mosses After the glacier retreats, bare ground is eventually colonized by lichens and mosses.

Fundamental v Realized Niche

many organisms within a community compete and therefore cannot occupy their full niche, they are limited in their role by others and display a "realized niche".

What moves through the community from one trophic level to another as organisms feed on one another?

matter and energy Matter is continuously recycled while energy is captured from the sun by plants and progressively lost at higher trophic levels.

Many wild orchids cannot be successfully dug up and transplanted because they need the native mychorrhizae (a fungus) in the soil to survive. What kind of interaction is this?

mutualism

The process that makes nitrogen available to plants by mutualistic and free-living bacteria is called __________.

nitrogen fixation The rhizobia bacteria live in root nodules. The plant supplies them with a habitat in which to live, water, and nutrients, and the bacteria supply nitrogen for making plant proteins.

Interspecific

occurs between individuals of different species

Intraspecific

occurs between individuals of the same species

In the carbon cycle, carbon moves from the atmosphere into the living portion of the cycle through ______.

photosynthesis Photosynthesis by green plants, algae, and cyanobacteria takes carbon from the atmosphere and turns it into living material.

Habitat

place where an organism lives. The specific environment in which an organism lives, including both biotic and abiotic factors.

Which one of the following is a general characteristic of plants that are early colonizers during primary succession?

plants have wind-dispersed seeds After the glacier retreats, bare ground is eventually colonized by lichens and mosses, then by deciduous trees with wind-borne seeds.

A cow eating grass is an example of a _____.

primary consumer By feeding on a producer, the cow is acting as a primary consumer.

In an ecosystem, phytoplankton are _____.

producers

Most energy in the majority of ecosystems arrives as ______ and exits in the form of _____.

radiation from the sun, heat Most of the energy in an ecosystem comes from the sun and gets passed through the ecosystem starting with photosynthesis. Each time energy passes to another trophic level in the ecosystem, some of that energy is lost to the universe as heat.

When a human eats a steak, the human is acting as a _____.

secondary consumer By feeding on a primary consumer, the human is acting as a secondary consumer.

A seal that just ate a clam is eaten by a shark. The shark is acting as a _____.

tertiary consumer The shark that ate the seal that ate the clam that ate the algae is the tertiary consumer.

Which of the following processes was responsible for humans increasing nitrogen's flux from the atmosphere to Earth's surface?

the Haber-Bosch process This process allowed people to overcome the lack of nitrogen available by natural nitrogen fixation by producing ammonia on a large scale.

Earth's oceans hold:

the bulk of all of the water found on Earth. The oceans contain 97.22% of all water, comprising about 1.321 billion cubic kilometers of salt water. This leaves only 2.78% of all of Earth's water as fresh water (non-oceanic).

The largest reservoir of carbon in the carbon cycle is in sedimentary rock that may take hundreds of millions of years to return to the living portion of the cycle. What is the second largest reservoir of carbon?

the oceans The oceans hold more carbon than all of the smaller carbon reservoirs combined. Any change in the oceans' ability to hold carbon will have a tremendous impact on the global climate.

Using "+" for those that benefit, "−" for those that are harmed, and "0" for no effect, which of the following expressions best represents competition between species?

− / −