MASTERING BIO EXAM 4

One focus of the Wog Wog project is to understand how reducing habitat size impacts extinction rates of different beetle species. Relevant data include numbers of individuals of a species that are captured over time in fragments of different sizes and in the control area. This question focuses on what subfield of ecology?

At Wog Wog, individual Eucalyptus trees at the edges of fragments grew faster over 25 years. One hypothesis is that trees on fragment edges grow faster because of reduced competition for water and hence reduced water stress. To test this idea, an undergraduate student proposed to compare water use in trees on fragment edges with trees in fragment interiors by measuring water transport in the xylem using electronic dataloggers. This question focuses on what subfield of ecology?

Post-doctoral researcher, Dr Andrew King, is studying how the rate of nutrient cycling of nitrogen and carbon has changed within Eucalyptus fragments compared to intact Eucalyptus forest in the control area. This question focuses on what subfield of ecology?

Graduate student, Jeff McClenahan, is studying how lots of different species of ants have responded to the fragmentation of their habitat. Ants compete strongly for food and territory but are also strongly affected by abiotic factors such as solar radiation, which warms their bodies and nests to different degrees depending on body size and coloration, and nest depth and materials (e.g. sandy soil versus a fallen log). Jeff has hypothesized that increased solar radiation in small fragments will favor some species, increasing their competitive ability and thus having a negative impact on others through competition and aggression. This question focuses on what subfield of ecology?

At Wog Wog, there was high mortality of old trees at the edges of fragments because, when the landscape was fragmented, the edges of fragments experienced more wind, and more trees were knocked over. This led to less competition between old trees and young trees for light and water at the edges of fragments, and, as a result, more young trees sprouted and grew. This means that now fragments have more young trees than intact forest. This change in the make up of young and old trees on fragments is due to:

In the Wog Wog experimental study, if an ecologist was interested in how changes in dryness, temperature and soil chemistry on habitat fragments impact survival of juvenile lizards, they are studying the effects of __________________ factors.

At Wog Wog, the abundance of beetles that are fungivores increased in fragments because there was an increase in woody debris that fungi decompose. The changes in the abundance in these beetle groups are due to:

During a field trip, an instructor touched a moth resting on a tree trunk. The moth raised its forewings to reveal large eyespots on its hind wings. The instructor asked why the moth lifted its wings. One student answered that sensory receptors had fired and triggered a neuronal reflex culminating in the contraction of certain muscles that raised the wings. A second student responded that the behavior frightens predators and that this allows the moth to escape. Which statement best describes these explanations?

Which of the following is a behavioral pattern that results from a proximate cause? A) A cat kills a mouse to obtain food. B) A female bird lays its eggs because the amount of daylight is decreasing slightly each day. C) A male sheep fights with another male because it helps it to improve its social position and find a mate. D) A goose squats and freezes motionless because that behavior helps it to escape a predator. E) A cockroach runs into a crack in the wall and avoids being stepped on

Which of the following is a behavioral pattern resulting from an ultimate cause? A) A male robin attacks a red tennis ball because it confuses it with an encroaching male who will steal his territory. B) A male robin attacks a red tennis ball because hormonal changes in spring increase its aggression. C) A male robin attacks a red tennis ball because a part of its brain is stimulated by red objects. D) A male robin attacks a red tennis ball because several times in the past red tennis balls have been thrown at it, and it has learned that they are dangerous. E) A male robin attacks a red tennis ball because it resembles the breast of another male.

Which one of the following predictions below would NOT be consistent with the reduced fertility hypothesis? A) The population growth rate (r) would be different on the two types of islands B) The birth rates per individual should be lower on islands where populations were declining C) Adult death rates should be similar on both types of islands D) Newly weaned pups are more likely to disperse from islands where the populations are declining

To explore whether the decline in population sizes was due to otters dispersing to new areas, the researchers marked individuals and conducted surveys of the populations of otters on different islands in the region. Which of the following predictions below would NOT be consistent with the different dispersal rates hypothesis? A) Mortality and birth rates should be similar on islands with and without population declines B) The number of sea otters disappearing from certain islands should lead to an increase in the number of otters on other islands C) The islands with declining population sizes have reached their carrying capacity D) All of the above would actually be consistent with the different dispersal rates hypothesis

What are population dynamics? A) Changes in populations through time. B) Proportion of individuals at each possible age. C) Regular fluctuations in the population size of some animals. D) Number of individuals born each year in a population.

Which of the following statements about age pyramids is true? A) Age distribution in less-developed countries is bottom-heavy, indicating that these populations are dominated by the very old. B) Populations in developed countries grow more quickly than populations in less-developed countries. C) Predictions of a population's future take into account such factors as increasing survivorship and fecundity levels that remain the same. D) Age distribution in developed countries shows an hourglass pattern, with the greatest numbers of people being either very young or very old.

True or false? The growth rate of a certain population increases very quickly for a time and then levels off to zero. The most likely reason that the growth rate leveled off to zero is that the environment reached its carrying capacity.

The average age of childbearing in country A is 26, whereas the average age in country B is 30. In each country, the average number of offspring per woman is 3. Which of the following statements about the population growth rate in each country must be true? (hint: think about the factors that affect growth rates). A)he population growth rate in country A is higher than in country B. B) It is not possible to compare the population growth rates of countries A and B. C) The population growth rates in countries A and B are the same. D) The population growth rate in country A is lower than in country B

In 1970, the average age of childbearing was 28, and the average number of offspring per woman was 3 in a certain country. In 1980, the average age of childbearing was still 28, but the average number of offspring per woman was 2 in that country. If the death rate in the country remained constant during those years, how did the population growth rate change from 1970 to 1980? A) The population growth rate increased. B) The population growth rate stayed the same. C) The population growth rate decreased. D) It is not possible to determine the population growth rate

Which of the following statements about energy flow are true? A) Animals that produce their own body heat and maintain a high body temperature are likely to be less efficient at converting food into biomass than are animals that do not regulate their body temperature. B) If the lowest trophic level of an ecosystem contains 1,200 grams of biomass per square meter, it is reasonable to expect the secondary consumer level to contain about 12 grams of biomass per square meter. C) Autotrophs typically capture about 90% of the available energy from the sun through photosynthesis. D) In a trophic pyramid, biomass represents chemical energy. E) Energy that could be used in the production of offspring by an animal is available to higher trophic levels. F) Energy contained in feces is available to higher trophic levels. G) Energy spent on cellular respiration is available to higher trophic levels.