Chapter 57, 58, 59.3-4 Practice

Which of these types of islands is predicted to have the lowest number of species?

A small island far from mainland

If gross primary production were to increase in an ecosystem, it would be reasonable to expect that

the biomass of herbivores would increase.

A positive feedback loop is one that tends to amplify a process. Why would the effect of deforestation on the water cycle be considered a positive feedback loop?

Because deforestation leads to a decrease in precipitation, which results in further loss of vegetation.

What type of populations would be most likely to show resource partitioning?

sympatric populations of species with similar ecological niches

Each year, many tons of fertilizer from residential and agricultural areas runs off into lakes, streams, and rivers, eventually making its way to the oceans. How does this impact aquatic ecosystems? Check all that apply. - There will be an increase or accumulation of limiting nutrients such as nitrogen and phosphorus, which support the growth of algae and other photosynthetic organisms. - Decomposition of excess algae will drastically reduce oxygen levels in aquatic ecosystems, making them unable to support other types of organisms. - Increased levels of nutrients will increase primary production and as a result increase the number of consumers, such as fish, that can be supported in aquatic ecosystems. - Areas where nitrogen and/or phosphorus are limiting factors will see an increase the biomass of primary producers. - An increase in the number of bacteria that feed on decomposing producers will offset any changes to the ecosystems brought on by the increased numbers of producers.

- There will be an increase in or accumulation of limiting nutrients such as nitrogen and phosphorus, which support the growth of algae and other photosynthetic organisms. -Decomposition of excess algae will drastically reduce oxygen levels in aquatic ecosystems, making them unable to support other types of organisms. -Areas where nitrogen and/or phosphorus are limiting factors will see an increase the biomass of primary producers.

Which of the following are defenses against herbivory?Check All That Apply - chlorophyll - terpenoids - nicotine - spines

- terpenoids - nicotine - spines

Top-down factors that can control the population sizes of plants or animals include which of the following factors? Select all that apply. - the density of herbivores - an extended period of drought - healthy populations of secondary carnivores - the presence of a fungal pathogen - nutrient-poor soil - levels of primary producers in the ocean

- the density of herbivores - healthy populations of secondary carnivores - the presence of a fungal pathogen

What biogeochemical cycles have been heavily affected by human activities? Check all that apply. - the water cycle - the phosphorus cycle - the nitrogen cycle - the carbon cycle

- the water cycle - the phosphorus cycle - the nitrogen cycle - the carbon cycle

Plants, algae, and cyanobacteria are primary producers upon which entire ecosystems are dependent. During photosynthesis, primary producers convert the carbon from inorganic carbon dioxide into organic compounds (glucose and other organic compounds). The amount of carbon that is processed during photosynthesis is referred to as gross primary production. Net primary production, however, is always less than gross primary production. Which of the following statements explain this difference? Check all that apply. - Only some of the carbon converted by the plant is used to create new biomass. - Plants utilize some of the incoming energy derived from photosynthesis for self-maintenance. - Some of the food that is made by producers is eaten by consumers thereby reducing primary production and the biomass available. - Primary production is limited by available nutrients. - Plants, algae, and cyanobacteria utilize light energy from the sun. - Plants and algae carry out cellular respiration, which requires biochemical energy produced during photosynthesis.

-Only some of the carbon converted by the plant is used to create new biomass. -Plants utilize some of the incoming energy derived from photosynthesis for self-maintenance. -Plants and algae carry out cellular respiration, which requires biochemical energy produced during photosynthesis.

What situation below is best characterized as interference competition?

A tiger that excludes other tigers from its territory.

Place each of the following into the appropriate category of competition.

Interspecific - interference competition - An eastern bluebird and a European starling compete for nest cavities by physical confrontations - If given the opportunity, a bold eagle will steal a fish that an osprey has caught rather than catching a fish itself. Interspecific - exploitation competition - White-tailed deer browse the understory of a deciduous forest, eating the vegetation that numerous other species depend on - Paramecium caudatum and P. Bursaria both show a drop in population densities when housed together Intraspecific - interference competition - During the breeding season, male elephant seals engage in vicious battles for control of a harem of females Intraspecific - exploitation competition - In late fall, American red squirrels scurry around the base of a white oak collecting as many acorns as possible for their individual winter food caches.

Fill in the sentences with the appropriate words. a. The ____________ states that two species with overlapping niches cannot survive together. One species will be driven to local extinction. b. In order for complete exclusion from an area to be avoided, ____________ can occur whereby similar sympatric species evolve slightly different ecological niches. c. If the evolution of different niches is the result of morphological changes, then ____________ has occurred. d. The evolution of morphological differences between two species should be greater when they are ____________ than when they are ____________ , due to selective pressures to diversify niches in the face of competition.

a. competitive exclusion hypothesis b. resource partitioning c. character displacement d. sympatric; allopatric

Complete the sentences explaining how early colonizers can facilitate the colonization of other species. a. One type of ______ succession begins after a glacier retreats leaving rocks and debris behind but not soil. b. Initially, ______ colonize the area and thrive despite the lack of soil. They are not dependent on a soil substrate and can prosper on barren rocky lands. As the initial colonizers die and decay, there is a build up of soil and an increasing amount of nitrogen and other nutrients in the substrate. c. As a result of ______ by the initiatial colonizers, flowering herbaceous plants are able to establish. As these species die and decay, the _____ will increase and become enriched with nutrients. d. With an increase in the soil depth and nitrogen, there is an emergence of species such as _____ , which is a fast growing tree species. The alder has nitrogen-fixing bacteria within its roots. e. Later colonizers, such as ______ begin to take over and dominate the faster growing species. The soil composition continues to be modified due to the break down of the needles from the evergreen trees, allowing the colonization by _____.

a. primary b. mosses and lichens c. facilitation; soil depth d. alder e. spruce trees; hemlock trees

Complete the following sentences. a. Different factors in terrestrial and aquatic ecosystems limit _______ . The _________ is the feature needed for growth that is in the shortest supply. b. In terrestrial ecosystems, the major limiting factors are water, ______ , and nutrient availability. In aquatic ecosystems, the major limiting factors are primarily ____ and secondarily nutrient availability. c. In the study shown in Figure 46.7 on primary production of a salt marsh sedge, it was determined that the limiting factor for growth was ______ . Once that factor was added, the new limiting factor was _______. d. In the world's oceans, natural _______ result in productive areas, while fertilizer-induced ______ often lead to dead zones.

a. primary production; limiting factor b. temperature; light c. nitrogen; phosphorus d. upwellings; algal blooms

Complete the sentences explaining the relationship between species richness and latitudinal variation. a. The number of species in a specific community, called _______, is influenced by latitude and general characteristics of the landmass. b. Higher latitudes have ____ species richness as compared to the lower latitudes. c. For a given latitude, an increase in _______, such as is found in moutainous areas, correlates with an _______ in species richness. d. In contrast, the ________, seen in areas that are further away from the main body of land, e.g., Florida and/or Baja California, see a _______ in species richness compared to other areas of the same latitude.

a. species richness b. lower c. topographical variation; increase d. peninsular effect; decrease

Food chains represent oversimplifications of producer-consumer relationships. Indicate if the following statements about interactions among trophic levels are true or false in explaining the complexity of these interactions. a. Plants may be consumed by many different species, which in turn are the potential prey of many other different species. b. Energy flows both from producers to consumers and from consumers to producers, which makes it difficult to depict relationships in a linear food chain. c. Species can be in more than one trophic level (e.g., might be both a primary and secondary consumer). d. While consumers get most of their energy by eating other organisms, most are also capable of producing their own food, blurring the line between producers and consumers. e. Decomposers might feed on plant leaves or branches that have fallen to the ground, making them primary consumers, but they might also feed on animal carcasses, making them secondary consumers. f. Decomposers are thought to be at the base of complex food webs, whereas producers are depicted as the base of most food chains.

a. true b. false c. true d. false e. true f. false

The Galapagos Islands were formed from underwater volcanic activity. The islands initially were barren, supporting no life, and then they went through a series of colonization stages. The equilibrium model of island biogeography states that the species composition on an island will constitute a balance between the immigration and extinction rates. Based on the equilibrium model of island biogeography, indicate if the following statements concerning succession on the islands are predicted to be true or false. a. Species arriving later might outcompete earlier arriving species, driving them to extinction. b. The number of species on an island decreases as a function of the distance from the source-pool (in this case, mainland South America). c. The number of immigrants will increase the closer the island is to the source. d. The rate of extinction will be lower on smaller islands due to small population sizes and less competition. e. The number of species on an island will increase with the increasing size of the island.

a. true b. true c. true d. false e. true

Select the accurate statement(s) concerning the phosphorus cycle. Check All That Apply - Phosphorus cycles globally via water and the atmosphere. - Phosphorus only cycles locally and therefore is relatively unimportant for aquatic ecosystems. - Overuse of fertilizer leads to eutrophication and can result in "dead zones". - There is a positive correlation between phosphorus levels and primary production. - Reduction of fertilizer and sewage effluent will have little effect on the recovery of fish populations in lakes and bays.

- Overuse of fertilizer leads to eutrophication and can result in "dead zones". - There is a positive correlation between phosphorus levels and primary production.

Animals have evolved many different antipredator strategies. Match the animal pictured with its antipredator strategy.

Chemical Defense - Jellyfish toxin Intimidation - Hissing cat Cryptic Coloration - Walking stick Aposematic Coloration - Brightly-colored poisonous Lionfish Armor - Tortoise shell

How is it possible that a community could have low species diversity, but high species richness?

If most of the individuals belonged to a single species.

For each pair of organisms, indicate whether the relationship is parasitic, mutualistic, or commensal.

Mutualism - hummingbirds/ plants with tube-shaped flowers - leaf-cutter ants/ fungus - ants/ acacia plants - squirrels/ oak trees Commensalism - orchids with no nectar/ bees - plants with hooked seeds/mammals - egrets/cattle - epiphytes/ tropical trees Parasitism - mosquito/mammals - leeches/fish - plants without chlorophyll/ growing plant with chlorophyll

Match the following descriptions with the appropriate trophic level.

Primary Producers - photosynthesizers - make their own food - oak trees Primary Consumers - consume producers - herbivores - deer Secondary Consumers - primary carnivores - small snake species Tertiary Consumers - secondary carnivores - bald eagles

Lead is known to undergo biomagnification and accumulate in bones. What do you predict will happen to lead taken up by a tiger after it dies in the wild?

The lead will reenter the food web via detritivores and decomposers.

No matter what model is used to show community succession, the final stage is always

a climax community.

Complete the following sentences and place them in a logical order. a. According to the ____________ model, control of population densities starts at ____________ trophic levels. b. Support for this model comes from the ____________ , which state that energy is lost with successive transfers through trophic levels, starting from ____________ and moving to ____________ , then to ____________ . c. Additional support comes from the fact that providing fertilizer to plants frequently has a pronounced ____________ effect on the population sizes, survivorship, fecundity, and growth of herbivores. d. However, some populations appear to be controlled by the presence and level of predation. Since predators occupy the ____________ trophic levels, predator-controlled populations are considered to be regulated from the ____________ .

a. bottom-up; the lowest b. laws of thermodynamics; primary producers; herbivores; carnivores c. positive d. highest; top-bottom

Match the following descriptions with the type of organism involved. a. Predators b. Herbivores c. Parasites d. Parasitoids

a. short but lethal interactions with prey b. short but non-lethal interactions with prey c. extended but non-lethal interactions with prey d. extended but lethal interactions with prey

In a hypothetical situation, a bacterium lives on the surface of a leaf where it obtains nutrients from the leaf's nonliving waxy covering, which the leaf continually produces. The plant is not hurt or harmed by this feeding. Once the number of bacteria reaches a critical mass, they inhibit the growth of other microbes that damage the plant. Occasionally, these bacteria can gain access to the interior of the leaf, for example, if there is weather-related leaf breakage the exposes the plant's interior tissues. If this occurs, the bacteria feed on the plant's living tissue, causing minor damage. What sequences best describes the ecological roles played by the bacterium in this situation?

commensalism→ mutualism→ parasitism

Disturbances to most communities, whether windstorms, floods, or the introduction of a new predator, are quite common. Community stability involves both the ability to resist change in the face of disturbance and the ability to recover from change induced by disturbance. The disturbance-stability hypothesis predicts that species-rich communities will be more stable than species-poor communities because

species-rich communities are more likely to have disturbance-resistant species that will increase in numbers in the face of a disturbance, compensating for disturbance-sensitive species that might decline in numbers temporarily.

True or False. Most of the Earth's phosphorus is trapped in sedimentary rocks.

true

Why are invasive species, like the Brown tree snake in Guam, so successful in their new range? Select all that apply. Check All That Apply - They are able to adapt to any type of climate. - Their new food source has no form of defense against them. - In their new range, they have few or no natural predators to control their population growth. - They can mimic other toxic species. - They have no carrying capacity in their new range.

- Their new food source has no form of defense against them. - In their new range, they have few or no natural predators to control their population growth.

Following a disturbance, a community goes through a predictable series of changes depending on the level and severity of the disturbance. For each description, indicate whether it is consistent with primary or secondary succession.

Primary Succession: - No plants, animals, or microbes present - Bare ground, no soil - Occurs after volcanic eruption - Occurs after a retreat of a glacier. Secondary Succession: - Supports life immediately following the disturbance - Occurs after a fire or tornado - Soil present - Severity varies, but it is never completely lifeless.

Predict the rank order of the following locations from lowest species richness to highest species richness, using the latitudinal gradient of species richness to form your prediction: temperate forest in North Carolina, steppe in Patagonia (southern tip of South America), rainforest in Costa Rica, boreal forest in Ontario (east-central Canada)

Steppe in Patagonia, Boreal Forest in Ontario, Temperate Forest in North Carolina, Rainforest in Costa Rica

The process by which elevated nutrient levels lead to an overgrowth of algae and the subsequent depletion of water oxygen levels is known as

eutrophication.

Which of the following exert bottom-up control?

levels of calcium and nitrogen in the soil