What is niche differentiation?

a. The evolution of traits that reduce niche overlap and competition

b. Interactions that allow species to occupy their fundamental niche

c. The degree to which the niches of two species overlap

d. The claim that species with the same niche cannot coexist

The relationship between corals and the photosynthetic protists they harbor is an example of

a. Commensalism.

b. Competition.

c. Consumption.

d. Mutualism

What is true about inducible defenses? Select True or False for each statement.

T/F They are always present; thus, an individual is always able to defend itself.

T/F They make it impossible for a consumer to launch surprise attacks.

T/F They result from a coevolutionary arms race.

T/F They make efficient use of resources, because they are produced only when needed.

Pioneer species tend to have high ________ and lower survivorship.

Cite an example to explain why species interactions are conditional and dynamic.

Evaluate this statement: Species want to increase their fitness by helping friendly species and hurting enemy species.

What is a disturbance? Consider the role of fire in a forest. Compare the consequences of high-frequency versus low-frequency fire, and high severity versus low severity of fire.

Draw a vertical food chain (part of a food web) showing that sea urchins eat kelp and that sea otters eat sea urchins.

Use this model to (1) show or explain how a trophic cascade works; and (2) offer an explanation for why otters are considered a keystone species.

In some circumstances, the use of probiotics, which stimulate the rapid growth of bacteria that are mutualistic or commensal with humans, can eliminate the need to use antibiotics, which can wipe out helpful bacteria along with harmful bacteria. The use of probiotics is an example of which process?

a. Succession

b. Competitive exclusion

c. Parasitism

d. Niche differentiation

Suppose that a two-acre lawn on your college's campus is allowed to undergo succession. Describe how species traits, species interactions, and the site's history might affect the community that develops.

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

In relation to humans, B. burgdorferi is a/an ____________ and the tick is a/an _____________.

a. endoparasite/ectoparasite

b. endoparasite/host

c. parasitoid/host

d. parasite/predator

The carnivorous plant Nepenthes bicalcarata ('fanged pitcher plant') has a unique relationship with a species of ant—Camponotus schmitzi ('diving ant'). The diving ants are not digested by the pitcher plants but instead live on the plants and consume nectar. Diving ants also dive into the digestive juices in the pitcher, swim to the bottom, and capture and consume trapped insects, leaving uneaten body parts and ant feces behind.

What nutritional impact do the ants have on fanged pitcher plants?

Do the pitcher plants derive any nutritional benefit from this relationship?

Researchers tested the hypothesis that the relationship between diving ants and pitcher plants is mutualistic (i.e., both species derive a nutritional benefit). To do so, they compared leaf surface area (as a measure of overall growth) in two sets of pitcher plants: plants with diving ants and plants without. The results are shown in the graph. The P values indicate whether there is a significant relationship between the size of the host plants and the surface area of the host plants' leaves. Based on this graph, what conclusions can be drawn about the impact of diving ants on overall plant growth?

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick, Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

Newly hatched ticks do not harbor B. burgdorferi. Rather, they pick it up from certain hosts that are reservoirs of the bacterium. When a larval tick crawls onto a host, it may get groomed off and killed by the host, or it may feed successfully, in which case it may or may not then become infected with B. burgdorferi. Felicia Keesing and others measured the rate of tick feeding and infection on different hosts.

What percentage of ticks on mice were infected with B. burgdorferi? What percentage of ticks on opossums were groomed off and killed?

The carnivorous plant Nepenthes bicalcarata ('fanged pitcher plant') has a unique relationship with a species of ant—Camponotus schmitzi ('diving ant'). The diving ants are not digested by the pitcher plants, but instead live on the plants and consume nectar. Diving ants also dive into the digestive juices in the pitcher, swim to the bottom, and capture and consume trapped insects, leaving uneaten body parts and ant feces behind.

What nutritional impact do the ants have on fanged pitcher plants?

Do the pitcher plants derive any nutritional benefit from this relationship?

Based on the background information presented here, does the relationship between diving ants and pitcher plants appear to be mutualistic? Explain.

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

Deer are hosts of ticks but are not reservoirs of B. burgdorferi—their immune systems detect and kill the bacterium. But a tick with a prior bacterial infection can consume a blood meal from a deer and then bite and infect a human. The fitness effects of a deer on B. burgdorferi can be summarized as:

a. + because the deer supplies the bacterium with food.

b. − because the deer kills the bacteria in its blood.

c. + because the deer feeds and disperses the tick that can then infect a human with the bacterium.

d. − or + depending on whether the deer is the tick's last host.

The carnivorous plant Nepenthes bicalcarata ('fanged pitcher plant') has a unique relationship with a species of ant—Camponotus schmitzi ('diving ant'). The diving ants are not digested by the pitcher plants but instead live on the plants and consume nectar. Diving ants also dive into the digestive juices in the pitcher, swim to the bottom, and capture and consume trapped insects, leaving uneaten body parts and ant feces behind.

What nutritional impact do the ants have on fanged pitcher plants?

Do the pitcher plants derive any nutritional benefit from this relationship?

Explain why carnivorous and parasitic plants are most common in nutrient-poor habitats.

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick, Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

Researchers have measured a positive correlation between forest fragmentation and incidence of Lyme disease. According to the theory of island biogeography, how do you predict fragmentation will affect species richness?

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick, Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

White-footed mice occupy a broad ecological niche—they occur in most communities regardless of habitat quality. Many other species, like the opossum, are absent from low-quality forest fragments. Based on this information and the data in Question 12, propose a hypothesis to explain the observed relationship between increased forest fragmentation and increased incidence of Lyme disease.

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in the inset, among red blood cells), which is transferred to humans via blood-sucking bites from the tick, Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term if not treated.

Why is Lyme disease on the rise in eastern North America?

A letter to the editor in a local newspaper asserts that 'we cannot afford to preserve natural forests, because we need to use these resources to help humans.' How could you respond to this comment in terms of Lyme disease?

The carnivorous plant Nepenthes bicalcarata ('fanged pitcher plant') has a unique relationship with a species of ant—Camponotus schmitzi ('diving ant'). The diving ants are not digested by the pitcher plants but instead live on the plants and consume nectar. Diving ants also dive into the digestive juices in the pitcher, swim to the bottom, and capture and consume trapped insects, leaving uneaten body parts and ant feces behind.

What nutritional impact do the ants have on fanged pitcher plants?

Do the pitcher plants derive any nutritional benefit from this relationship?