5 Written questions
5 Matching questions
- This graph shows the effect of removal of urchins and limpets (alone and together) on seaweed cover. Select the statement that accurately describes the results shown in this graph.
Sea urchins have a much greater effect than limpets in limiting seaweed cover.
Removing only limpets increased seaweed cover dramatically.
The lack of change over time in the control plots (with urchins and limpets present) shows that limpets and urchins have no effect on seaweed cover.
- 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.
- In Australia, researchers tested the hypothesis that sea urchin abundance limits kelp distribution. Select the evidence that offers the best support for this hypothesis.
There is an inverse relationship between the abundance of sea urchins and the abundance of kelp.
When sea urchins were removed from experimental plots, kelp cover increased.
Sea urchins graze on kelp.
- Female spotted sandpipers aggressively court males and, after mating, leave the clutch of young for the male to incubate. This sequence may be repeated several times with different males until no available males remain, forcing the female to incubate her last clutch. Which of the following terms best describes this behavior?
certainty of paternity
- The feeding relationships among the species in a community determine the community's
- a When sea urchins were removed from experimental plots, kelp cover increased.
- b A population with a positive value of r will grow exponentially.
- c trophic structure
- d Sea urchins have a much greater effect than limpets in limiting seaweed cover.
- e polyandry
5 Multiple choice questions
- natural selection favors altruistic acts when the resulting benefit to the beneficiary, corrected for relatedness, exceeds the cost to the altruist.
- Mechanoreceptors detect sound.
Foods taste spicy when they activate the same sensory receptors that high temperatures activate.
- the ecological footprint of the United States is large because per capita resource use is high.
- winds blowing from west to east along the equator.
- Changes in the behavior of cross-fostered young provide information about how the social and physical environment influences behavior.
Cross-fostering studies provide information about the relative importance of nature and nurture in the development of a trait.
5 True/False questions
Which of the following could qualify as a top-down control on a grassland community?
limitation of plant biomass by rainfall amount
effect of humidity on plant growth rates
effect of grazing intensity by bison on plant species diversity
influence of temperature on competition among plants
influence of soil nutrients on the abundance of grasses versus wildflowers → adding nitrogen-fixing microorganisms to a degraded ecosystem to increase nitrogen availability
Select the correct statement describing the nitrogen cycle.
Nitrogen-fixing microbes provide energy for carbon fixation.
Denitrifying bacteria reduce ammonia (NH3 +) to molecular nitrogen (N2).
Bacteria obtain energy from nitrification. → Bacteria obtain energy from nitrification.
Which of the following is true of innate behaviors?
Their expression is only weakly influenced by genes.
They are expressed in most individuals in a population.
They occur in invertebrates and some vertebrates but not mammals.
They are limited to invertebrate animals.
They occur with or without environmental stimuli. → They are expressed in most individuals in a population
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. → The intercalated disks allow coordinated contraction of the whole heart.
What is a likely outcome of a moderate disturbance, such as a severe thunderstorm?
Select all that apply.
Reduced species diversity within a community
Patches of different habitats within the landscape
Loss of an equilibrium state of balance, leading to a less healthy community → Patches of different habitats within the landscape