Test 3 MB
A population is growing exponentially and its instantaneous growth rate (r) is 0.02. Would the number of individuals added to the population (rN) be greatest at a population size (N) of 20, 500 or 1000?
1000
Offer a hypothesis to explain why humans have undergone near-exponential growth for over 500 years
Advances in nutrition, sanitation, and medicine have allowed humans to live at high density without suffering from decreased survivorship and fecundity.
You can get mercury poisoning if you eat daily meals of tuna, a top predator. However, you can safely eat sardines, which are primary consumers, every day. What biological process explains this?
Biomagnification
Which processes increase a population's size?
Births and immigration.
Which of the following statements about density-independent growth is true?
Density-independent growth is also known as exponential growth.
Which of the following statements about a population experiencing logistic growth is true?
If N is greater than K, the population will shrink.
Which factor does not affect a habitat's carrying capacity?
Maximum number of individuals in a population.
Which species interaction applies to bees that harvest nectar and pollen from flowers?
Mutualism
What is net primary productivity (NPP)?
Primary producer biomass or organic material that can be consumed
Why is terrestrial productivity higher in equatorial climates?
The answer is most likely a combination of the other responses.
In the hypothesis that C. stellatus (a species of barnacle) is competitively excluded from the lower intertidal zone by B. balanoides (another species of barnacle), what could be concluded about the two species?
The fundamental and realized niches of B. balanoides are identical, but the fundamental and realized niches of C. stellatus are different
What best explains hare and lynx population cycles?
The interaction of food availability and predation intensity
In general, NPP is much higher on land than in the oceans. Why?
The leading hypothesis is that there is more light available on land than in the ocean.
Which habitats are the most productive?
The tropical rain forests and coral reefs
What is the fundamental niche of Chthamalus?
The upper and lower intertidal zones
Why does net productivity diminish with increasing trophic levels?
There is poor trophic transfer efficiency at higher trophic levels
Which of the following is TRUE of species interactions?
They can act as agents of natural selection
Which of the following is a consequence of biomagnification?
Toxic chemicals in the environment pose greater risk to top-level predators than to primary consumers.
True or false? Factors that determine the per capita rate of increase of a population include the age of breeding and the number of offspring produced each year.
True
Most of the net primary productivity that is consumed is used for growth by primary consumers.
True; most NPP is used for growth by primary consumers.
Why might one get mercury poisoning from eating tuna every day, but not from eating sardines from the same water?
Tuna biomagnify the mercury.
Which category in the figure makes available the highest productivity per square meter?
algal beds and reefs
For most terrestrial ecosystems, pyramids composed of species abundances, biomass, and energy are similar in that they have a broad base and a narrow top. The primary reason for this pattern is that
at each step, energy is lost from the system
Random spacing patterns in plants such as the creosote bush are most often associated with...
chance
An egret eats insects stirred up by grazing animals. Which of these terms applies to the relationship between the egret and the grazing animal?
commensalism
Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This situation is an example of what kind of species interaction between the birds and the ants?
commensalism
Which process is not an example of consumption?
commensalism
Humans and sharks both eat fish. Which of these terms applies to the relationship between the human and the shark?
competition
Which species interaction depends on prey density and effectiveness of prey defenses to determine the impact on the prey population?
consumption
The study of factors that determine the size and structure of populations through time is called
demography
If two species are close competitors, and one species is experimentally removed from the community, the remaining species would be expected to
expand its realized niche
Choose two examples of density-dependent factors that may influence human population growth
famine, disease
Natural selection involves energetic trade-offs between
high survival rates of offspring and the cost of parental care
In a particular case of secondary succession, three species of wild grass all invaded a field. By the second season, a single species dominated the field. A possible factor in this secondary succession was
inhibition
Humans who have pets tend to be healthier than humans who do not have pets. Which of these terms applies to the relationship between a human and a pet?
mutualism
When primary producers invest energy to build new tissue, this is
net primary productivity and the amount of energy available to consumers
Which of these terms applies to the relationship between a dog and a blood-sucking tick?
parasitism
You own 300 acres of patchy temperate forest. Which one of the following actions would increase the net primary productivity of the area the most?
planting 500 new trees
A human eats a deer. Which of these terms applies to the relationship between the human and the deer?
predation
Logistic growth of a population is represented by ΔN/Δt =
rN(K-N)/K
Exponential growth of a population is represented by ΔN/ Δt =
rmax N
The study of the Zootoca vivipara lizard showed that
the low-elevation Netherlands population was intermediate for fecundity and survivorship when compared with other populations
True or false? One example of a coevolutionary arms race is when faster deer evolve and favor wolves and cougars that have stronger eyesight and senses of smell.
true
Which equation represents the logistic growth rate of a population?
ΔNΔt=rmaxN(K−N)K
