biology Unit 2 Exam

According to the law of conservation of matter, matter is never created or destroyed. Yet in a food pyramid the amount of biomass decreases as we move up through the pyramid, from producers to top level consumers. Why?

Matter changes to other forms that might not continue to be a part of the same food chain.

Which nutrient cycle is most affected by the over-use of ammonia fertilizers on commercial farms, as well as by the accumulation of waste on cattle farms and feed lots?

Nitrogen cycle

Carbon dioxide is returned to the atmosphere primarily by the

Respiration of consumers

What is a community?

All the different populations that live together in an area same place same time

The burning of coal, a fossil fuel, produces water and carbon dioxide. How is this similar to cellular respiration?

Both involve the breakdown of carbon compounds

The burning of fossil fuels by cars and factories has most affected the ______________ cycle.

Carbon

Phosphorus and sulfur are returned to the soil primarily by the actions of

Decomposers

How do sulfur and phosphorus move from the biotic to the abiotic pools during their cycles?

Decomposers break down the remains of producers and consumers

The original source of energy in most ecosystems is

the sun

An isolated African canyon community in which cheetahs and leopards consume only impala antelopes is being observed. If the number of leopards increases, which change is MOST LIKELY to be the first to occur after the leopard population increase?

The impala population will decrease

What is an organism?

an individual living thing that is made of cells, uses energy, reproduces, responds, grows, and develops

The total amount of organic matter present in any trophic level is called

biomass

Consider the aquatic phosphorus cycle. Phosphorus is the limiting nutrient for aquatic organisms. Decomposition naturally returns phosphorus to the aquatic cycle, but phosphates from fertilizers, sewage and detergents can cause pollution in lakes and streams. Over-enrichment of phosphate in freshwater can lead to __________ which, when they die and decay, leads to _____________.

Algal blooms; eutrophication

In any food web, plants are considered to be producers. They convert sunlight (solar energy) into usable chemical energy (glucose). When we eat plants our bodies are using that chemical energy. What elements are rearranged to make glucose in plants?

Carbon, Hydrogen, Oxygen

How does Secondary succession form?

Forms when community is disrupted by a natural disaster or human actions

What two processes fuel the carbon cycle?

cellular respiration and photosynthesis

What is population?

A group of organisms all the same species which interbreed and live in the same place at the same time

78% of Earth's atmosphere is nitrogen gas. All living things need nitrogen as a part of DNA and RNA. Yet you and I, and other living things, cannot use the nitrogen in our atmosphere directly. One type of organism is responsible for "fixing" nitrogen or helping to put it in a form so other living things can use it. That organism is

Bacteria

If a population grows larger than its environmental carrying capacity, then

Death rate may rise

If a population grows larger than the carrying capacity of an ecosystem, the

Death rate rises

The snake does not get as much energy from eating the same amount of food as the grasshopper. The statement that best explains why this is true is

Grasshoppers use up much of their energy for life processes.

The growth rate of a population that has a limited food supply will MOST LIKELY be

Logistic

Note that the phosphorus cycle contains elements that are labelled as loss. Explain.

Lost phosphorus is actually recycled through the processes of mineralization, reabsorption, dissolving, and precipitation

The size of a food web is limited by the number of

Primary producers

The relationship of two species that can be represented as +/0 would best be described as

commensalism, one species benefits, one unaffected.

Which sequence lists the water cycle in order?

evaporation, condensation, precipitation, runoff/storage

Mako sharks weigh about 1000 pounds when they reach maturity. Suppose that in a gulf near South America, the following food chain exists Diatom algae -> Sardines -> Blackfin tuna -> Mako Shark A plankton tow estimates that there are about 100 million pounds of diatoms in the gulf. How many adult mako sharks can the gulf support?

100

Where does primary succession form?

2 sources Volcanic lava flow cools and forms rock or glaciers retreat and expose rock

Clouds dump around 100 billion gallons of water on rainforests each year. How much rain is evaporated from the rivers, lakes and surface of rainforests each year?

Around 100 billion gallons; If it were significantly less, it woud eventually be a desert. If it were significantly more, it would eventually be a giant lake.

The single most important limiting factor in any terrestrial biome is

Available water

Nitrogen in the atmosphere must be "fixed" before it can be used by plants. Atmospheric nitrogen is "fixed" by

Bacteria and lightning

What type of organism would recycle a dead tree in the forest?

Decomposer

When the members of a population reproduce at a constant rate and overshoot the carrying capacity of their environment, it is called _______________ growth.

Exponential growth

Plants need nitrogen in order to survive. The problem is they cannot take in the atmospheric nitrogen, but instead must rely on a certain class of bacteria that are able to turn atmospheric nitrogen into other nitrogen compounds, such as ammonia and nitrates. What is the name of this process?

Nitrogen fixation

Which organisms have the most energy available to them?

Plants or producers

What is the difference between primary and secondary succession?

Primary starts on bare rock and takes a longer time reaching a climax community, while secondary succession starts on soil and doesn't take as long to reach a climax community

Sulfur and phosphorus compounds enter bodies of water, such as ponds, lakes, and rivers

as run-off containing fertilizers and detergents.

What are the levels of organization?

organism, population, community, ecosystem, biome, biosphere

What is an ecosystem?

populations of plants and animals that interact with each other in a given area with the abiotic components of that area?

All energy in any ecosystem starts as

sunlight

What is a pioneer species?

the first species to colonize barren areas Ex. lichen, moss

A farmer had an accident and spilled a chemical into his pond. Several days later, he notices many dead frogs around the pond. That summer, the number of gnats around the pond was higher than ever. This is because

the frogs are a limiting factor for the gnats.

What is a climax community?

the stable, mature community that undergoes little to no succession

A mature wolf weighs an average of about 70 pounds. On a certain island in the Great Lakes, wolves primary prey is moose. A mature moose weighs an average of about 700 pounds. Suppose that there is a population of 50 moose on the island. Approximately how many wolves can be supported?

50

What is a biome?

A group of ecosystems, same climate, similar types of communities

There is much interdependence among the biogeochemical cycles on Earth. How is warmer ocean water involved in these cycles?

Atmospheric carbon dioxide, a greenhouse gas, would cause rising ocean temperatures, which will cause an increase in evaporation. The added water vapor would further increase global warming.

Why is the predator/prey relationship not an example of symbiosis?

Because the predator solely seeks to kill the prey for food as a means of survival Symbiosis someone benefits from the relationship but is never immediately killed

Barnacles are a type of arthropod in the subphylum Crustacea, and are related to crabs and lobsters. Barnacles are exclusively marine, tend to live in shallow and tidal waters, or attached to larger organisms. Barnacles are sessile; that means they do not move about. The image shows barnacles attached to the tail of a humpback whale. In this relationship, the barnacles derive benefit. There is not benefit or harm to the whale. This relationship is an example of

Commensalism

Bluebirds and blue jays, two bird species live in a small wooded area. The blue jays are very aggressive and eventually take over the nests of the bluebirds. This is an example of interspecific

Competition

The diagram of a hypothetical rabbit population can be seen here. In this instance we could imagine an increase in the death rate and a subsequent decrease in birth rate. A direct result would be a gradual increase in the rabbit population, until eventually, the pattern see here would repeat. What is one factor we could introduce that would more than likely help to stabilize the rabbit population over time?

Predators such as fox or wolves

An energy pyramid is a graphical model of energy flow in a community. The different levels represent different groups of organisms that compose a food chain. An energy pyramid's shape shows how the amount of useful energy that enters each level. Chemical energy, in the form of food, decreases because some is used by the organisms in each level. The source of the chemical energy is the producers, that rearrange carbon dioxide and water in the presence of light to make ________ through the process of ______________.

Sugars; photosynthesis

In the pyramid, only about 10 percent of the __________ is available within one trophic level is transferred to organisms at the next trophic level.

Energy

In a food chain 90% of the energy is lost in the transfer at each trophic level, and only 10% passes as usable biological energy. What will happen if secondary consumers are removed from a food chain?

Energy transfer to the subsequent trophic levels of the food chain will be disturbed.

The carrying capacity of any population will stay the same unless

Environmental changes occur

Rivers, springs, and aquifers are all fresh water components of the hydrologic cycle. As this water progresses through the cycle, it will eventually ___________ into the atmosphere before ____________ and falling back to the earth as precipitation.

Evaporate; Condensing

In the water cycle water returns to the atmosphere by the process of

Evaporation

We consider the water cycle to act as a system. Outputs in this system would be

Evaporation and transpiration

As levels of carbon dioxide increase in the atmosphere, we could expect oceanic carbon dioxide levels to _____ and oceanic pH to _____ .

Increase; Decrease

During cellular respiration, every living thing in this food web uses ______ gas and releases ______ back into the environment.

Oxygen; Carbon dioxide

Which process changes solar energy into organic matter so that it can be cycled through a food chain?

Photosynthesis

Following the evaporation stage of the water cycle, the evaporated water

Precipitates to the ground

The diagram shows a numbers pyramid for a forest community. Imagine that there is only one producer, a tree. This seems to contradict the concept of the typical food pyramid. All but one statement explains how this model is also correct.

The autotrophs would typically have the highest number of organisms with each level above it containing roughly 90% less.

Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle. Human activities are altering the carbon cycle, by adding more CO2 to the atmosphere and by influencing the ability of natural sinks, like forests, to remove CO2 from the atmosphere. While CO2 emissions come from a variety of natural sources, human-related emissions are responsible for the increase that has occurred in the atmosphere since the industrial revolution. Consider the graph above. Notice the trend in atmospheric carbon dioxide as recorded at recording stations over Antarctica. Hypothesize how the schematic of the carbon cycle might change if urbanization and deforestation continues unchecked.

The photosynthesis carbon sink will decrease in gigatons; the carbon dioxide output due to combustion will increase.

Plants take in the increased ground water and use the water for photosynthesis. Plants also release water into the atmosphere as a by-product of cellular respiration. What process returns the water to the water cycle?

Transpiration

Precipitation and evaporation are important components of the

Water cycle

Consider the aquatic phosphorus cycle. On land most phosphorus is found in rocks and minerals. In the oceans, phosphorus is deposited from decomposition, excretion from animals, run-off from the land, and finally ______________ of rocks and minerals.

Weathering

What is biosphere?

portion of earth that supports life

Some species of nitrogen-fixing bacteria have adapted to grow in nodules of legumes such as peas and clover. These bacteria make nitrogen available to the plant and in turn, receive nutrients from the tissues of the plant. This type of interaction is known as

Mutualism

What happens to the amount of available energy in the pyramid as it moves up through the different levels?

It decreases

Clownfish have evolved resistance to the deadly stings of sea anemones. The sea anemone provides protection for the clownfish from predators and leaves the uneaten remains of its prey for the clownfish to finish off. Meanwhile the clownfish helps attract prey to the sea anemone with its bright colors. The relationship between clownfish and sea anemones is a form of symbiosis called

Mutualism

What would MOST LIKELY happen to the grass if most of the fungi and bacteria die?

The grass will not grow as well

Above is an example of a food chain or pyramid. Ultimately, either directly or indirectly all organisms on this food chain get their energy from what single source?

The sun

Consider the diagram of the water cycle. Assume that deforestation has taken place. How will this effect the movement of water through this model?

Transpiration will decrease

Ecological pyramids can be based on the numbers of individual organisms at each ________ level

Trophic

Abiotic factors: -40c to 10c; annual precip

Tundra

Carbon is a major component of all organic compounds, including carbohydrates, lipids, proteins, and nucleic acids. Carbon dioxide is continually exchanged between the atmosphere and oceans. What geological process returns carbon to the atmosphere in the form of carbon dioxide?

Volcanic activity