Relationships Between Organisms Quiz

In parasitism, one species benefits at the expense of another. A common example of this type of symbiotic relationship is ticks feeding on dogs. The ticks gain nourishment by consuming the dog’s blood, which may also lead to health issues for the dog by transmitting diseases. This interaction underlines the complex nature of ecological relationships, where not all interactions are mutually beneficial.

Based on the passage, what is a primary characteristic of parasitic relationships?

A) Both species involved are harmed.
B) Both species benefit equally.
C) One species benefits while the other is harmed.
D) Neither species gains any significant advantage.

Commensalism is a type of symbiotic relationship where one species benefits and the other is not significantly affected. An example of this is barnacles attaching to whales. The barnacles benefit from increased mobility and access to more nutrient-rich waters, while the whale does not experience any notable harm or benefit from carrying the barnacles.

What does the example of barnacles on whales illustrate about commensalism?

A) It demonstrates a harmful relationship between different species.
B) It shows a relationship where both species gain significant benefits.
C) It provides an example where one species benefits and the other is not affected.
D) It indicates a mutual dependency for survival between two species.

Predator-prey dynamics are crucial for maintaining ecological balance and controlling population sizes within ecosystems. For example, wolves preying on deer help regulate the deer population, which prevents overgrazing and promotes forest health. This relationship highlights the importance of predators in maintaining natural order and ensuring the sustainability of various habitats.

What role do predators play in ecosystems according to the passage?

A) They solely increase the prey population.
B) They destabilize the population dynamics.
C) They have no significant impact on the environment.
D) They contribute to ecological balance by controlling prey populations.

In ecosystems around the world, symbiotic relationships can have profound effects on the environment and biodiversity. A notable example is the relationship between clownfish and sea anemones. In this mutualistic relationship, the clownfish gains protection from predators by living among the toxic tentacles of the sea anemone, which is immune to the anemone’s sting. In return, the clownfish provides the anemone with nutrients in the form of waste, which helps the anemone thrive.

What does the relationship between clownfish and sea anemones demonstrate about mutualistic symbiosis?

A) It shows that one species always dominates the other in symbiotic relationships.
B) It illustrates how two species can benefit each other for survival and health.
C) It proves that symbiotic relationships are typically detrimental to one of the species.
D) It indicates that all symbiotic relationships involve nutrient exchange.

Predator-prey dynamics play a critical role in maintaining the health of ecosystems. A well-documented example is the reintroduction of wolves into Yellowstone National Park, which had cascading effects on the ecosystem. By preying on the overpopulated elk, wolves helped reduce their numbers, which allowed vegetation to recover.

This recovery supported an increase in biodiversity, including the return of species such as beavers and birds that rely on healthy forests and rivers.

What impact did the reintroduction of wolves into Yellowstone National Park have on the ecosystem?

A) It led to the extinction of several local species.
B) It decreased biodiversity due to increased predation.
C) It resulted in the overpopulation of elk in the park.
D) It helped restore ecological balance and increased biodiversity.