Exam 4

Which of the following is FALSE regarding factors that determine biomes? a. The capacity of air to hold water decreases as it is cooled at high altitudes. b. Biomes found at high altitudes can also be found near the equator at low elevations. c. The curvature of the earth's surface as well as the tilt of its axis contribute to the varying levels of solar radiation that different parts of the earth experience during the course of a year. d. Winds appear to move on a curved path due to the Coriolis Effect.

Biomes found at high altitudes can also be found near the equator at low elevations.

In 1987, 18 black-footed ferrets, the last known individuals of this species, were captured and brought into a captive breeding program in Wyoming. In 1989, the total ferret population, still in captivity, was 120 animals. What is r?

[(120-18)/2]/18

On average, individuals of a grassland butterfly population live for 3 months, reproduce once per lifetime, and lay approximately 100 eggs per brood. Given this information, which of the following statements is FALSE? a. If the butterflies began to live for 2 months, the population would likely grow. b. If the butterflies began to reproduce three times per lifetime but laid the same number of eggs per brood, the population would likely grow. c. If the butterflies began laying 200 eggs per brood, the population would likely grow. d. If the butterflies began to live lay 50 eggs per brood the population would become smaller.

a. If the butterflies began to live for 2 months, the population would likely grow.

Which of the following statements is TRUE regarding acid rain? A. Acid rain is a direct cause of global warming. B. Acid rain is higher in pH than regular rain water. C. Acid rain is caused by burning coal and is found in areas where most industrial coal use is found. D. Acid rain is the main cause of the "dead zone" in the Gulf of Mexico.

acid rain is caused by burning coal and is found in areas where most industrial coal use is found

Which of the following is TRUE regarding a feature shared among these nutrient cycles?

all nutrients rely on microbes for their cycling

Of the following choices, which lists organisms in an ecosystem in order of: primary producer, primary consumer, secondary consumer, tertiary consumer? a. kelp, sea urchin, sea otter, killer whale (orca) b. grass, grass hopper, vole, owl c. tree, beetle, bird, lynx

all of the above

The process of ____ produces NH4+ by bacteria and fungi; the process of ___ produces N2 by bacteria.

ammonification; denitrification

A population can decrease in size as a result of which of the following processes?

an increase in death rate

Of the following, which is an example of an area in which primary succession could occur? a. A evergreen forest in which a tornado has severely damaged a wide area of plant life. b. An abandoned agricultural field. c. A savanna that has been damaged by fire. d. An island recently formed in the ocean by a volcano.

an island recently formed in the ocean by a volacano

Consider a population undergoing logisitic growth. When (K - N)/K = 0, what does that imply about the birth rate (b) and death rate (d)?

b=d

The volcanic oceanic island of Krakatoa is located in Indonesia. In 1883, this island experienced a massive volcanic explosion that killed most of the plants and animals living on the island. After recovery from the eruption, which group of organisms would we expect to re-colonize the island first?

beetles

The movement of mineral nutrients through organisms and their environment is called a ___ .

biogeochemical cycle

Which of the following would NOT be expected to affect gross primary productivity?

biomass of primary consumers

Threespine sticklebacks are a type of fish who have recently been used to demonstrate character displacement. In these fish, when two closely related types are present in the same lake, they have two separate body types - a bottom feeding body type and an open water feeding body type. What would you expect to see when only one species is present in a lake?

both species would display an intermediate body type if found alone in the lake

Which of the following is the biggest reason CO2 levels have increased so dramatically?

burning of fossil fuels

disturbances

can influence the diversity of a species in a community.

Which of the following statements is TRUE regarding the movement of carbon between organisms in a food web and the transfer of energy between organisms in different trophic levels?

carbon can be continuously cycled and energy cannot

The maximum number of individuals of a given population the environment can support is the environment's _____ for that population.

carrying capacity

Remoras, or sucker fishes, are known to attach themselves to the bellies of sharks, as shown above. As the shark swims, the remora benefits by collecting the shark's food scraps. The shark is not harmed by the remora. The relationship between the remora and the shark can be best described as:

commensalism

In some rocky intertidal habitats, the barnacle Chthamalus can survive across the same depths as can the barnacle Balanus. However, where the two occur together, Chthamalus adults are found only in the more stressful upper portions of the habitat where they are more prone to desiccation. This is an example of:

competitive exclusion reducing the size of Chthamalus' fundamental niche to a smaller realized niche.

The same scientist continues to study the same population of feral cats in his city. After ten years, he notes that—for the population of feral cats he is studying—(K-N)/K = 0. Based on this information, what can he deduce about the logistic growth curve for the population at this point in time?

curve has plateaued at K

Moderate temperatures and precipitation, as well as nutrient-rich soil due to annual leaf fall, characterize this biome

deciduous forest

Which group in a food web is responsible for returning organic compounds back to the environment?

decomposers

Whooping cranes nest in marshes near the Atlantic coast and can be flooded and destroyed during severe hurricanes. This is an example of (meaning the flooding):

density independent limiting factor

The rain shadow effect accounts for what type of biome often being found near a mountain whose opposite side is adjacent to a body of water?

desert

Which of these biomes receives the least amount of rainfall, and therefore has low primary production, nutrient-poor soil, and plant species that are adapted for water-storage?

desert

Which of the following would be considered a density-independent factor that could affect the growth of a population?

droughts

You decide to plant a garden in your backyard. You dig up a strip of grass in a sunny spot. When you have finished digging up the grass, but you haven't planted anything, you have created a/an ______________ in the lawn

ecological disturbance

Glacier Bay in Alaska is a fjord whose lowlands were covered by glacial ice until around 230 years ago. As the glacier retreated, glacial till was exposed to plant colonization; remarkably (and fortunately for generations of ecologists), the location of the tip of the retreating glacier has been frequently documented since the late 1700's. This means that scientists have been able to develop a detailed timeline of the changes in the plant community, or _____ in Glacier Bay over time.

ecological succession

A country with zero population growth is more likely to be:

economically developed

When a population is small relative to its carrying capacity, its growth will be:

exponential

human population growth right now is

exponential

In what northern hemisphere season would you expect oxygen levels to be highest?

fall (CO2 was closest so O2 is highest)

Cellular respiration is a process unique to animals, and is not undertaken by plants. (T/F)

false

True or False: K-strategists tend to inhabit "unpredictable" environments and also have population densities near the carrying capacity of an environment.

false

True or False: Nothing can be done to alter the impact of future human activity on the environment.

false

A ____ is a sequence of behaviors that, once triggered, is followed through to completion.

fixed action pattern

The coast redwood (Sequoia sempervirens) occurs naturally in a strip of habitat about 450 miles long and 5-35 miles

geographic range

the coast redwood (Sequoia sempervirens) occurs naturally in a strip of habitat about 450 miles long and 5-35 miles wide, from southwest Oregon along the coast to just south of Monterey, California. What aspect of the population ecology of the coast redwood does this statement describe?

geographic range

In response to global climate change, it is likely that some plant species will survive while others will go extinct. All of the following are explanations of this pattern EXCEPT:

greenhouse gases are toxic, so increasing levels of these gases will cause some plants to go extinc

As a population approaches its carrying capacity, its growth rate:

growth rate decreases; r stays the same

This is a graph of a Paramecium population growing in culture over a period of 30 hours. If space is a limiting factor for this population, then the addition of food will ...

have no effect

Remember that, as a rule, temperatures decrease with altitude. If you were studying the effects of climate change on the geographic ranges of species living in the mountains and your climate records showed that mean temperatures were increasing, you would predict that species ranges would show a shift toward:

higher elevations

Which of the following statements reflects changes over approximately the past 130 years in hummingbirds and their utilization of the spring breeding grounds?

hummingbirds are arriving earlier on the breeding grounds

Kin selection is believed to have evolved due to selection for alleles that increase an organisms':

inclusive fitness

Humans have increased their carrying capacity on Earth. Which of the following is an example of how humans have done this?

increasing crop yields to produce more food in the same amount of space

An instinctive behavior that is due to the role of genotype alone and regardless of experience is a(n) _____ behavior.

innate

The per capita growth rate (r) is synonymous with:

intrinsic growth rate

Imagine that a population of meerkats exhibits an exponential growth curve. What does this tell you about the intrinsic growth rate (r) of the meerkat population?

intrinsic growth rate has remained constant

A population that is decreasing in size will have an age-structure histogram shaped like a(n):

inverted pyramid with a narrow base representing a small number of young individuals

Exotic/non-native/invasive species are especially threatening to what type of ecosystem?

island

Which of the following statements is true regarding the process of eutrophication?

it can result in dead zones devoid of aquatic animal life

Giant clams synchronize their reproduction with the phases of the moon. During these reproductive bouts a single clam can release approximately 500 million eggs to be fertilized in the water column by sperm released from other clams. However, the population sizes of giant clams are very low because many of the fertilized eggs and larvae will be eaten by fish in the local area. Based on this information what can be said of the reproductive strategy of the giant clam?

it is an r strategist

The age structure histogram for the population of India is shaped like a pyramid (see figure below). What does this tell you about India's population?

it is growing

Which of the following best describes a species' niche?

its habitat and how it uses available resources in its habitat

After the soil is enriched with nitrogen, spruce take over and dominate the landscape. What reproductive strategy do you think spruce have?

k selected

Saguaro cacti are large cacti commonly found in the American southwest. These can be up to 60 feet tall, and may live up to 75 years. Few large seeds are produced in multiple reproductive events. What would you expect to be the reproduction strategy of a saguaro?

k selected

A _____ affects other members of the community in ways that are disproportionate to its abundance or biomass.

keystone speicies

The form of natural selection that promotes behaviors that help close relatives is called _____.

kin selection

Most populations demonstrate ____________ growth, in which the population size increases exponentially until it levels off near the K value of the habitat for that species.

logistic

Although humans have the characteristics of a K-selected species, human population growth is currently exponential. As the Earth's human population grows:

most growth will be in underdeveloped nations

Cows have bacteria in their rumen that are able to digest cellulose. What type of relationship is this?

mutualism

In 1987, 18 black-footed ferrets, the last known individuals of this species, were captured and brought into a captive breeding program in Wyoming. In 1989, the total ferret population, still in captivity, was 120 animals. These 120 animals in 1989 represented:

n, the total population size

Most reptiles are observed to experience a near constant death rate throughout their lifespan. As such, what type of life history strategy are reptiles likely to have?

neither k or r selected

Which of the following is most likely to lead to resource partitioning?

niche overlap

A major constituent of Earth's atmosphere is nitrogen gas (N2), making up 79% of the air we breathe. Primary producers such as plants and algae cannot assimilate this form of nitrogen into biomolecules. Instead they rely on bacteria and archaea to convert N2 to ammonia (NH3). This important biological reaction is called:

nitrogen fixation

During _____, N2 from the atmosphere is converted to ammonia, which plants can assimilate.

nitrogen fixation

What is generally true about biomass and energy as we move from one trophic level to the next?

not all energy is transferred to the next trophic level

When calculating population growth what factors must be known?

number of births and deaths, immigration and migration into and out of the population

Organisms in an ecosystem are linked to their physical environment through the cycling of _______ and the transfer of _________.

nutrients; energy

Aphids are small insects that suck sugars from the phloem of plants. The ecological relationship between plants and aphids is

parasitism

Which type of interaction is not antagonistic?

parasitism

During exponential growth, the number of individuals added per unit time increases, while the _____ stays the same.

per capita growth rate

Where would you expect to fine the most photosynthesis in an ocean biome?

photic zone

Which biological process accounts for maximum CO2 levels observed in spring (May) and for lowest CO2 levels observed in fall (September)?

photosynthesis

Which of the following would NOT contribute to increasing CO2 levels? respiration. photosynthesis. deforestation. Burning of fossil fuels

photosynthesis

Which of the following processes are typically associated with the carbon cycle?

photosynthesis and respiration

You are given 100 acres of land and asked to use the land for long-term reduction of atmospheric CO2 levels. Which of the following is the best use of the land for this purpose?

plant trees that grow rapidly, reach a large size and live for a long time

A scientist is studying a population of feral cats in his city. He notes that the r of this population is 1. What does this mean (assuming that he is evaluating population size on a yearly basis)?

population of feral cats doubles in size each year

Herbivores belong to which group in a food web?

primary consumers

Organisms that take up inorganic nutrients and convert them to organic molecules such as carbohydrates and proteins are called _______________.

primary producers

The carbon in a food web primarily comes from:

primary producers

An r-strategist will typically:

produce many small offspring

a hiker up a mountain could observe changes in biomes by changes in

rainfall, elevation, temperature

This is a graph of a Paramecium population growing in culture over a period of 30 hours. If food is a limiting factor for this population, then the addition of food will ...

raise k

The ______________ of a species is usually the result of predation, competition, and other types of interaction between species

realized niche

Salvia leucophylla is a flowering plant that grows in California. Its roots produce toxic chemicals preventing other plants from growing near it. What type of spatial distribution patter would you expect in populations of S. leucophylla?

regular (uniform)

Competitive exclusion may lead to one species's survival and another's death. However this can be avoided if a population evolves to make use of a different resource that is being competed for. This is called:

resource partitioning

Which of the following is expected to reduce competition among individuals?

resource partitioning

Which of the following is FALSE about how climate change is affecting our planet? A. Some animals compensate for climate change by altering their migration patterns. B. Glaciers are melting at a faster rate, which may lead to increased sea levels. C. Some animal breeding times are now earlier in the year and breeding times are often shorter. D. Many plants are blooming later in the year than what is considered normal.

Many plants are blooming later in the year than what is considered normal.

Which of the following are "usable" forms of nitrogen (N) and sulfur (S) that plants can use to build proteins?

SO4 and NO3

If plants consume CO2 during photosynthesis, why hasn't all the atmospheric CO2 been used up?

respiration uses CO2 as a product

Measuring its costs and benefits in terms of energy spent and/or gained, predation :

results in gain for one individual and loss for another

The majority of water found on earth is in:

saltwater

After tearing up the soil for your garden, you become so busy with school you completely forget about planting the garden. When you remember a few weeks later, you go back to see a bunch of small plants have started growing. This is an example of ___ and these plants are likely ___ species.

secondary succession; r selected

A K-strategist would be more likely to live in a _____ environment.

stable

You sample the solid waste of three infants from three different families each week for 24 weeks. You find that the population of bacteria in the gut is dominated by one species for the first 12 weeks, and then shifts to another species. This shift in the biological composition of a community over time is called:

succession

A small population of rats was placed on an island with ample resources and no predators. What can be said about its population growth?

The population growth will be exponential until the population size approaches the carrying capacity of the island.

_____ are close interactions between species that have evolved over long periods of time. When these interactions enhance the reproduction and population growth of both species, they are called _____.

symbiosis and mutualisms

In a pond, tadpoles eat algae and fish eat the tadpoles. Around the pond, grasshoppers eat grass and, at night, are preyed upon by bats. Other bats eat the fish that eat the tadpoles. Both types of bats may be eaten by hawks. In this community, the fish-eating bats are:

tertiary consumers

Which of the following statements are FALSE regarding the biogeochemical cycling of Nitrogen? a. Currently, nitrogen inputs from industry and agriculture exceed input from natural sources. b. Nitrogen fixation by microorganism converts the gaseous form of nitrogen into a form that can be used by other organisms. c. Nitrogen is a major component of fertilizer, run off of which is the main cause of eutrophication. d. The active pool of nitrogen is large compared to the small reservoir of N2 gas.

the active pool of nitrogen is large compared to the small reservoir of N2 gas

If the major food source of the seals declines due to overfishing, which of the following would likely occur?

the carrying capacity of the seals would decrease as would the seal population

As a population approaches its carrying capacity, how does its growth change?

the growth rate slows until N is close to K

In class, we discussed how removal of P. ochraceus, a starfish, resulted in dominance of M. californicus, a mussel, in the rocky intertidal zones of the Pacific Northwest. When P. ochraceus is present, macroinvertebrates are found in the ecosystem. When P. ochraceus is removed, M. californicus are plentiful but the numbers of macroinvertebrates are greatly reduced. This result is an example of:

top down effect

Sexual selection is a behavior that always favors

traits that increase an individuals access to reproductive opportunities

Tropical rain forests are typically found at or very near the equator. Which of the following statements are likely to be FALSE about tropical rain forests? a. Tropical rain forests have a high primary productivity. b. Tropical rain forests experience a high level of precipitation. c. Tropical rain forests have a high average yearly temperature. d. Tropical rain forests receive only oblique rays of solar radiation.

tropical rain forests receive only oblique rays of solar radiation

This biome is situated around the equator and boasts the greatest biodiversity of any biome.

tropical wet forest

At its earliest stages, a logistic growth curve closely resembles an exponential growth curve.

true

If the biomass that can be supported in higher trophic levels is dependent on the number of primary producers, then the diversity should increase as latitude decreases.

true

This biome is the coldest, with the lowest biodiversity and a permanent layer of ice beneath the soil.

tundra

As human mortality is greatest during later life stages (and most children survive into adulthood), humans demonstrate a __________ survivorship curve

type I

Giant clams synchronize their reproduction with the phases of the moon. During these reproductive bouts a single clam can release approximately 500 million eggs to be fertilized in the water column by sperm released from other clams. However, the population sizes of giant clams are very low because many of the fertilized eggs and larvae will be eaten by fish in the local area. What type of survivorship curve would you expect to see in giant clams?

type III

Many weeds produce a high number of seeds which are dispersed widely. Typically, only a few of these seeds will grow to mature plants. What type of survivorship curve would you predict a weed to have?

type III

What type of survivorship curve would you expect for a typical r-strategist?

type III

As mice produce several offspring that do not normally survive into adulthood (and mortality rates are highest during the first few months of life), these animals would exhibit a:

type III survivorship curve

Which of the following statements are FALSE regarding sigmoidal growth curves? a. When N = K, growth rate will be zero. b. When N<<<K, the population size will grow. c. When N<<<K, density dependent factors will significantly affect the growth rate of a population.

When N<<<K, density dependent factors will significantly affect the growth rate of a population. *when N=K density dependent factors will signficantly affect the growth rate of a population

The flow of energy in ecosystems is described as being inefficient. What percent of energy transferred between trophic levels is converted into body mass?

10%

Imagine a population of 10 individuals. If this population triples in one year, what is the per capita growth rate?

2

If 5000 kilograms of biomass are available at the primary consumer level, on average how many kilograms of biomass would be available to the tertiary consumers?

50