Question 1

Use this description to answer the following question.
Experts in white-tailed deer ecology generally agree that population sizes of deer that live in temperate climates are limited by winter snow. The deer congregate in "yarding" areas under evergreen trees because venturing out to feed in winter is energetically too expensive when snowfall depths accumulate to above 40 cm. Deer often stay yarded until the spring thaw. Snow depth over 40 inches for more than 60 days results in high mortality due to starvation.
-This observation best illustrates which of the following principles about factors that limit distribution of organisms?

Accepted Answer

The answer of Use this description to answer the following...

Question 2

Which of the following is true with respect to oligotrophic lakes and eutrophic lakes?

Accepted Answer

Eutrophic lakes are richer in nutrients, which leads to greater plant growth and higher levels of productivity. In contrast, oligotrophic lakes have very low nutrient levels, which limits productivity and leads to clearer water but greater susceptibility to oxygen depletion.

Question 3

Which lake zone would be absent in a very shallow lake?

Accepted Answer

The aphotic zone is absent in a very shallow lake because this zone is characterized by a lack of sunlight, which is not applicable in shallow lakes where sunlight can penetrate to the bottom.

Question 4

Which of the following is characteristic of most terrestrial biomes?

Accepted Answer

Most terrestrial biomes demonstrate vertical layering of vegetation, with different types of plants growing at different heights. For example, in a tropical rainforest, there are often multiple layers of trees, shrubs, and groundcover plants. This feature is one of the defining characteristics of terrestrial biomes.

It is incorrect to choose: 
A) because annual average rainfall can vary widely among different biomes, from less than 25 cm in the desert to over 500 cm in tropical rainforests. 
B) because while rock and soil patterns can influence biome distribution, other factors such as climate, latitude, and human activity also play a significant role. 
C) because there are often transitional areas between adjacent biomes, rather than clear boundaries. 
E) because some biomes, such as tropical rainforests and savannas, do not have cold winter months.

Question 5

Use the following diagram from the text showing the spread of the cattle egret, Bubulcus ibis, since its arrival in the New World, to answer the following question.
 
-How would an ecologist likely explain the expansion of the cattle egret?

Accepted Answer

The diagram shows that the expansion of the cattle egret in the New World followed the range of cattle, which provided a suitable habitat for feeding. Additionally, the areas to which the cattle egret expanded were likely lacking in native herons and egrets, allowing the cattle egret to occupy a previously unoccupied niche. Ecologically speaking, this is known as the "empty niche hypothesis," which suggests that introduced species can thrive and expand in areas where there are no native competitors or predators. Therefore, an ecologist would likely explain the expansion of the cattle egret in the New World as a result of the species finding a vacant ecological niche that met its biotic and abiotic requirements.

Question 6

When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes

Accepted Answer

The transition in biological communities when climbing a mountain is similar to the changes in biome at different latitudes, as both involve changes in temperature, precipitation, and other environmental factors that influence the types of species that can survive in each area.

Question 7

Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?

Accepted Answer

Tropical rain forests have a vertical layering with multiple strata: the emergent layer, the canopy layer, the understory layer, and the forest floor. This allows for a greater number of bird species due to the availability of more habitats and resources. Savannas and deserts, for example, have fewer vertical strata and therefore fewer bird species. The temperate broadleaf forest and temperate grassland also have fewer strata compared to the tropical rain forest.

Question 8

The oceans affect the biosphere in all of the following ways except

Accepted Answer

The oceans do not directly regulate the pH of freshwater biomes or terrestrial groundwater, as these are separate systems.

Question 9

Which of the following biomes is correctly paired with the description of its climate?

Accepted Answer

Tropical forests are characterized by nearly constant day length and temperature throughout the year due to their location near the equator. This leads to a stable climate with little variation in temperature across seasons, which is not the case for the other biomes listed.

Question 10

Use this description to answer the following question.
In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce are displaced from their normal vertical alignment.
-What might be the adaptive significance of these unusual forests growing the way they do in this marginal habitat?

Accepted Answer

In permafrost regions, the ground is too hard for trees to develop deep taproots. Instead, black spruce and similar species adapt by forming shallow root systems that spread out near the surface, which contributes to their displaced or "drunken" appearance.

Question 11

Which statement about dispersal is false?

Accepted Answer

Dispersal can occur within a single generation and does not necessarily require an evolutionary time scale.

Question 12

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?

Accepted Answer

Landscape ecology focuses on the exchange of energy, organisms, and materials between ecosystems, examining spatial patterns and the interactions across different ecosystems.

Question 13

If the direction of Earth's rotation reversed, the most predictable effect would be

Accepted Answer

If the Earth's rotation were to reverse, the most predictable effect would be a change in the direction of prevailing winds, including those along the equator, which would then blow from west to east. This is because the direction of Earth's rotation influences the direction of the Coriolis effect, which in turn affects wind patterns.

Quiz 52: An Introduction to Ecology and the Biosphere