AN OLD GENERAL ECOLOGY EXAM 1 & 2

Disclaimer: Some of the material included on this exam was not covered in General Ecology during September and October 2006. Not all material covered in General Ecology during September and October 2006 is represented by questions below (e.g., natural selection). In other words, treat this as an example of the types of questions that may be found on Exam 1 & 2, not an all-inclusive set of questions for all information covered during September and October 2006.

Multiple Choice

1. How many major terrestrial biomes are there?
a) 6
b) 5
c) 4
d) 3

2. Which of the following is a trace element (micronutrient)?
a) phosphorus
b) zinc
c) calcium
d) nitrogen

3. A cohort life table is easiest to construct for organisms with what type of life cycle?
a) continuous semelparity
b) continuous iteroparity
c) overlapping iteroparity
d) annual

4. An example of a modular organism might be
a) a mouse.
b) a snake.
c) a Hydra.
d) an earthworm.

5. Endotherms
a) are unaffected by changing environmental temperatures.
b) exhibit constancy of performance over a wide range of environmental temperatures.
c) depend heavily on behavioral mechanisms to moderate body temperature.
d) maintain relatively constant body temperatures of 30-35°C, depending on species.

6. Carbon dioxide
a) is used up rapidly by photosynthesizing plants.
b) diffuses into depleted zones rapidly.
c) seldom becomes limiting under natural conditions.
d) all of the above

7. Which is not a characteristic of grasslands?
a) periodic severe drought
b) animal life dominated by grazing and burrowing species
c) annual rainfall of 100-250 mm
d) high rate of evaporation

8. The rate of photosynthesis
a) is maximized only if the products of the process are withdrawn.
b) is lower in shade species than in sun species at all light intensities.
c) continues to increase in most plants as light intensity increases to maximum levels.
d) is never zero in total darkness.

9. Territory defense is a type of
a) amensalism.
b) exploitation competition.
c) interference competition.
d) logistic competition.

10. Plant roots
a) branch less in soils that contain more moisture.
b) can extract all the water from soils if necessary.
c) grow only in soils with a water content at or above the field capacity.
d) none of the above

11. In the absence of niche differentiation, interspecific competition results in
a) competitive exclusion.
b) a broadening of niches of competing species.
c) a narrowing of niches of competing species.
d) the coexistence of competing species.

12. Poikilotherms
a) maintain a constant body temperature.
b) regulate body temperature by internal heat production.
c) display variable body temperatures under varying environmental temperatures.
d) include birds and mammals.

13. Unlike high temperatures, low temperatures can
a) destroy or denature enzymes.
b) reduce energy expenditures in ectotherms.
c) kill organisms.
d) all of the above

14. A mediterranean climate generally supports
a) coniferous forests.
b) shrublands.
c) tallgrass prairie.
d) deserts.

15. Migration of organisms typically results in what type of distributions?
a) clumped
b) uniform
c) dispersed
d) random

16. Semelparous organisms
a) have a life span of less than one year.
b) invest little energy in reproduction.
c) die after reproducing.
d) reproduce several times during their lives.

17. The life cycle of a salmon would be described as
a) continuous iteroparity.
b) overlapping iteroparity.
c) continuous semelparity.
d) overlapping semelparity.

18. A static life table
a) is most often used for short-lived organisms like annuals.
b) can show patterns of mortality for long-lived organisms.
c) is constructed by collecting data on a group of organisms of the same age from their
birth to their death.
d) cannot be used in conjunction with a fecundity schedule.

19. Monophagous animals
a) are generalist feeders.
b) are adaptable to changes in food supply.
c) have the ability to break down cellulose.
d) none of the above

20. Herbivores
a) are generally unselective feeders.
b) obtain most of their nutrition from microbes colonizing the plants they consume.
c) may use microbes to aid in the digestion of plant materials.
d) have low carbon to nitrogen ratios.

21. Terrestrial plants can reduce water loss by
a) opening stomata during the day.
b) developing structures that reduce leaf temperature.
c) making the water diffusion gradient between leaf and air steeper.
d) wilting.

22. A desert cactus
a) has a taproot reaching to the water table.
b) has more biomass below ground than above
c) has roots extending 30 m laterally from the stem.
d) has very shallow roots.

23. Oxygen
a) seldom is limiting in the terrestrial (aerial) environment.
b) concentrations in water-saturated soils are often too low to support the growth of
many plants.
c) in aquatic habitats imposes physiological, morphological, and behavioral constraints
on aquatic animals.
d) all of the above

24. Niche differentiation is
a) accentuated by interspecific competition.
b) found only among allopatric organisms.
c) the most obvious effect of intraspecific competition.
d) the primary cause of local extinctions of organisms.

25. The compensation point refers to
a) the lowest wavelength of light that plants can use for photosynthesis.
b) the level of light intensity where the products of photosynthesis are equivalent to the
materials used for respiration.
c) the lowest light intensity capable of supporting photosynthesis.
d) none of the above

26. Plants with a high leaf area index (LAI) typically
a) are shade-tolerant.
b) achieve maximum rates of photosynthesis at low light intensities.
c) have lower leaves that continually carry on photosynthesis.
d) live in areas of high light intensity.

27. Plants use
a) less than 5% of the solar energy striking them.
b) approximately 44% of total solar radiation.
c) more solar radiation when their leaves are not perpendicular to the sun.
d) less total solar radiation than do photosynthetic bacteria.

28. Altered pH can affect organisms by
a) altering the quality or range of available food resources.
b) upsetting osmoregulation.
c) altering the concentrations of toxic metals.
d) all of the above

29. The actual environmental limits within which a species can survive, grow, reproduce, and maintain a viable population in the presence of competitors and predators is the
a) realized niche.
b) ecotype niche.
c) ecological niche.
d) fundamental niche.

30. Macronutrients
a) have differing properties of absorption and diffusion.
b) all exhibit wide resource depletion zones around plant roots.
c) are needed in only small amounts.
d) are required in similar quantities and proportions by different species.

31. The effects of intraspecific competition are
a) theoretically symmetric.
b) density independent.
c) not detectable at population levels below carrying capacity.
d) evident in all organisms in their natural environments.

32. Natural populations seldom maintain stable densities at carrying capacity because of
a) stable environmental conditions.
b) factors other than intraspecific competition affecting individuals.
c) constant resource levels.
d) all of the above

33. According to Bergmann's rule, mammals in colder climates will
a) have shorter ears than relatives in warmer regions.
b) have thicker fur than relatives in warmer regions.
c) have larger bodies than relatives in warmer regions.
d) have longer legs than relatives in warmer regions.

34. Today grasslands have been reduced to what fraction of their former acreage?
a) 1/2
b) 1/3
c) 1/8
d) 1/20

35. The distributions of organisms are most often limited by
a) lethal low temperatures.
b) hardening capabilities.
c) lethal high temperatures.
d) suboptimal temperatures.

36. Which of the following is true regarding "r" calculated from life tables?
a) It represents the maximum life expectancy of any individual in the population.
b) The population will tend to decrease in size if it is less than 0.
c) It represents the fecundity of the average female in the population.
d) It will always equal 1 in organisms with Type II survivorship curves.

37. In aquatic habitats, oxygen concentrations
a) decrease as temperature decreases.
b) increase as organic matter increases.
c) decrease as biological oxygen demand increases.
d) none of the above

38. The Q10 rule
a) describes an endotherm's physiological response to changing temperatures.
b) concerns a ten-fold change in reaction rate for each 10°C change.
c) describes an ectotherm's optimum temperature for growth.
d) is important to the development of some organisms.

39. Individual organisms
a) are adapted to the environmental conditions present in their habitats.
b) with high fitness leave proportionately more offspring than do less fit individuals.
c) cannot adjust to cyclic environmental changes.
d) can be grouped into prototypes that locally match the environment.

40. Ectotherms
a) can moderate heat exchange with the environment.
b) have no costs associated with temperature regulation.
c) cannot function in cold temperatures (<15°C).
d) all of the above

Essay. Choose any two of the following.

#1. Compare and contrast convergent evolution, parallel evolution, and coevolution. Provide an example of each.

#2. Describe reproductive success and the genetic similarity of mating individuals in the context of dispersal by organisms. Use a diagram to illustrate your description.

#3. Describe all potential outcomes of the competitive interaction between Species A and Species B. Assume that we know nothing of their intra- or interspecific competitive abilities.

#4. Describe four benefits and two negative aspects associated with clumped distributions of organisms.