Deck 38: Animal Ecology

Question 1

How would you distinguish between ecosystem, community, and population

Answer 1

When organisms of the same species exist together it is called a population.
When two or more populations of different species exist together it is called a community.
When different communities come together it is known as ecosystem.

Question 2

The pyramid of energy has been offered as an example of the second law of thermodynamics (p. 10). Why

Answer 2

The Second Law of Thermodynamics states that physical systems tend to move towards a state of greater disorder or entropy. This law states that whenever energy is changed from one form to another, there is always a "loss" of energy in the form of heat. This heat is responsible for the disorder or entropy seen.
The pyramid of energy is seen as an example of this law of thermodynamics as we see the loss of energy from each trophic level from producers to consumers. This loss of energy fulfills the second law of thermodynamics.
The producers produced
out of which herbivores used
. The first-level carnivores used
out of
and the second level used
out of 383 kcal.

Question 3

What is the distinction between habitat and environment

Answer 3

A habitat is the specific space inhabited by a particular species which includes the environment. Many habitats make up the environment.

Question 4

Animal communities surrounding deep-sea thermal vents apparently exist in total independence of solar energy. How is this existence possible

Question 5

Define the niche concept. How does the "realized niche" of a population differ from its "fundamental niche" How does the concept of niche differ from the concept of guild

Question 6

What do paleontological studies show about the relationship between the geographic range of a species and its probability of undergoing speciation or extinction How does this present a paradox for biodiversity

Question 7

Populations of independently living (unitary) animals have a characteristic age structure, sex ratio, and growth rate. However, these properties are difficult to determine for modular animals. Why

Question 8

Explain which of the three survivorship curves in Figure 38.2 best fits the following: (a) a population in which mortality as a proportion of survivors is constant; (b) a population in which there is little early death and most individuals live to old age; (c) a population that experiences heavy mortality of the very young but with the survivors living to old age. Offer an example from the real world of each survivorship pattern.

Figure 38.2 Three principal types of theoretical survivorship curves. See text for explanation.

Question 9

Contrast exponential and logistic growth of a population. Under what conditions might you expect a population to exhibit exponential growth Why cannot exponential growth be perpetuated indefinitely

Question 10

Growth of a population may be hindered by either density-dependent or density-independent mechanisms. Define and contrast these two mechanisms. Offer examples of how growth of the human population might be curbed by either agent.

Question 11

Herbivory is an example of an interspecific interaction that is beneficial for the animal (+) but harmful to the plant it eats ( ). What are some + interactions among animal populations What is the difference between commensalism and mutualism

Question 12

Explain how character displacement can ease competition between coexisting species.

Question 13

Define predation. How does the predator-prey relationship differ from the parasite-host relationship Why is the evolutionary race between predator and prey one that the predator cannot afford to win

Question 14

Mimicry of monarch butterflies by viceroys is an example of a palatable species resembling a toxic one. What is the advantage to the viceroy of this form of mimicry What is the advantage to a toxic species of mimicking another toxic species

Question 15

A keystone species is defined as one whose removal from a community causes the extinction of other species. How does this extinction happen

Question 16

What is a trophic level, and how does it relate to a food web

Question 17

Define productivity as the word is used in ecology. What is a primary producer What is the distinction between gross productivity, net productivity, and respiration What is the relation of net productivity to biomass (or standing crop)

Question 18

What is a food chain How does a food chain differ from a food web

Question 19

The term ecology is derived from the Greek meaning "house" or "place to live." However, as used by scientists, the term "ecology" is not the same as "environment." How do these terms differ

Question 20

What conditions produce an inverted pyramid of biomass in which the consumers have a greater biomass than the producers Can you think of an example of an inverted pyramid of numbers in which there are, for example, more herbivores than plants on which they feed