Examine the climograph for some major North American biomes. Which two factors influence the distribution of organisms, as shown in this climograph?
The presence of tundra and presence of forested land
Annual mean temperature and annual mean precipitation
The presence of broadleaf and presence of coniferous forest
Plasma membranes of adjacent cardiac muscle cells interlock at specialized regions called intercalated disks. What is the significance of this feature of cardiac muscles?
The intercalated disks play the same role as striations of skeletal muscle.
The intercalated disks generate action potentials within the heart muscle without nervous system input.
The intercalated disks allow coordinated contraction of the whole heart.
Consider a population whose growth over a given time period can be described by the exponential model: dN/dt = rN. Select the correct statement about this population.
A population with an r of 0 will have no births or deaths during the time period under consideration.
A population with a positive value of r will grow exponentially.
A population with an r of 0.1 will decrease over time.
Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?
Which of the following is true with respect to oligotrophic lakes and eutrophic lakes?
Sediments in oligotrophic lakes contain larger amounts of decomposable organic matter.
Eutrophic lake water contains lower concentrations of nutrients.
Rates of photosynthesis are lower in eutrophic lakes.
Eutrophic lakes are richer in nutrients.
Oligotrophic lakes are more subject to oxygen depletion.
aThe intercalated disks allow coordinated contraction of the whole heart.
cA population with a positive value of r will grow exponentially.
dEutrophic lakes are richer in nutrients.
eAnnual mean temperature and annual mean precipitation
5 Multiple Choice Questions
Behaviors with a genetic component can evolve through natural selection.
the cultural tradition of using stones to crack nuts has arisen in only some populations.
an open ocean
tropical regions generally have more available water and higher levels of solar radiation.
tropical rain forest
5 True/False Questions
A region of the canary forebrain shrinks during the nonbreeding season and enlarges when breeding season begins. This change is probably associated with the annual
renewal of mating and nest-building behaviors.
sensitive period in which canary parents imprint on new offspring.
addition of new syllables to a canary's song repertoire.
crystallization of subsong into adult songs.
elimination of the memorized template for songs sung the previous year. → landscape ecology
Which statement accurately describes the potential effects of disturbance on species diversity?
Moderate levels of disturbance generally act to reduce species diversity within a community.
In many biomes, periodic disturbances may eliminate the dominant plants.
Many species are well adapted to survive periodic disturbances. → Many species are well adapted to survive periodic disturbances.
Identify the correct statement(s) about sensory receptors.
Select all that apply.
Mechanoreceptors detect sound.
Foods taste spicy when they activate the same sensory receptors that high temperatures activate.
Electromagnetic receptors detect pheromones. → Behaviors with a genetic component can evolve through natural selection.
During the contraction of a vertebrate skeletal muscle fiber, calcium ions
spread action potentials through the T tubules.
break cross-bridges by acting as a cofactor in the hydrolysis of ATP.
transmit action potentials from the motor neuron to the muscle fiber.
re-establish the polarization of the plasma membrane following an action potential.
bind with troponin, changing its shape so that the myosin-binding sites on actin are exposed. → bind with troponin, changing its shape so that the myosin-binding sites on actin are exposed.
Scientific study of the population cycles of the snowshoe hare and its predator, the lynx, has revealed that
the hare population is r-selected and the lynx population is K-selected.
the prey population is controlled by predators alone.
both hare and lynx populations are regulated mainly by abiotic factors.
hares and lynx are so mutually dependent that each species cannot survive without the other.
multiple biotic and abiotic factors contribute to the cycling of the hare and lynx populations. → multiple biotic and abiotic factors contribute to the cycling of the hare and lynx populations