Question 1

Which of the following is true of predation?

Accepted Answer

The answer of Which of the following is true of...

Question 2

In contrast to predation, a parasite usually

Accepted Answer

The definition of a parasite is an organism that lives on or in a host organism, but does not usually kill it. Therefore, choice A is the best option as it accurately describes the difference between predation and parasitism.

Question 3

Populations are held in check by

Accepted Answer

All of these factors can contribute to keeping populations in check. Resource partitioning can limit the amount of resources available to each individual within a population, limiting its growth. Predation can directly reduce population size by consuming individuals, as well as indirectly by selecting for traits that make individuals better at avoiding predators. Social parasitism can result in a reduction in resources available to the host population. And competition can limit access to resources, leading to lower population growth rates. All of these factors can act in combination to help regulate populations.

Question 4

How are parasitoids different than parasites?

Accepted Answer

Parasitoids differ from parasites in that they ultimately kill their host, whereas parasites typically do not kill their host.

Question 5

The interaction in which one species benefits and the second species is neither harmed nor benefited is

Accepted Answer

In commensalism, one species benefits and the second species is neither harmed nor benefited. This is different from mutualism, where both species benefit, and parasitism or predation, where one species benefits and the other is harmed. Competition involves both species being negatively affected.

Question 6

The monarch butterfly is poisonous to birds and so birds avoid eating them. Viceroy butterflies look very similar to monarch butterflies but are not poisonous. Because they look like monarch butterflies, birds also do not eat viceroy butterflies. This is an example of

Accepted Answer

This scenario is an example of mimicry, where the viceroy butterfly has evolved to look like the poisonous monarch butterfly in order to avoid being eaten by birds who have learned to avoid eating monarchs. This is not resource partitioning, as it does not involve dividing up resources to reduce competition, nor is it competitive exclusion, as both species are able to coexist without one outcompeting the other. Camouflage and commensalism are not applicable here.

Question 7

Phorid flies lay their eggs inside the bodies of various insects and spiders. When the larvae hatch they consume the body of the 'host' from the inside out. The phorid fly is an example of

Accepted Answer

Phorid flies are parasitoids, which are organisms that lay their eggs inside or on another organism, eventually killing the host as the larvae consume it from the inside out. This is in contrast to brood parasites, which lay their eggs in the nests of other species to be raised by the host parents, and commensalists, which benefit from a relationship with another organism without harming or benefiting the host. Competitive excluders are organisms that outcompete other species for resources.

Question 8

The bacterium, E.coli , lives in the large intestines of mammals and feeds on undigested food material. E.coli helps to synthesize vitamin K that is essential for mammalian blood clotting. The relationship between E.coli and mammals is a

Accepted Answer

The relationship between E.coli and mammals is mutualism because E.coli benefits by feeding on undigested food material and living in a suitable environment, while mammals benefit from the synthesis of essential vitamin K by E.coli.

Question 9

The subdividing of some category of similar resources in a way that allows competing species to exist is

Accepted Answer

Resource partitioning is the subdividing of a category of similar resources in a way that allows competing species to coexist. This allows for a decrease in competition and an increase in biodiversity within an ecosystem.

Question 10

Which of the following is an adaptation against predation?

Accepted Answer

All of these are adaptations against predation. Thorns physically deter herbivores and predators, camouflage helps organisms blend in with their surroundings and avoid detection, mimicry allows organisms to look like other organisms that are toxic or not palatable to predators, and tough, chewy leaves are difficult for herbivores to digest and may contain toxins to deter them from eating the plant.

Question 11

A sheep eating by pulling the plant out of the ground is an example of

Accepted Answer

The act of a sheep pulling a plant out of the ground and eating it qualifies as predation, as the sheep is directly consuming and killing the plant for its own benefit. Parasitism involves one organism (the parasite) benefiting at the expense of another (the host), but in this case, the plant is not a host to the sheep. Commensalism involves one organism benefiting from the presence of another without harming or benefiting it in return, but the sheep is clearly benefiting from consuming the plant. Mutualism involves two species benefiting from their interactions with each other, but there is no other species involved in this scenario. Competitive exclusion involves two species competing for resources, but there is no indication that any other species is involved in the interaction between the sheep and the plant.

Question 12

Hover flies like to drop in at outdoor picnics to sample the sweets, but the reaction of humans is to flee the scene because of the flies' uncanny resemblance to bees. Thus the survival of Hover flies is enhanced by

Accepted Answer

The behavior of Hover flies to mimic the appearance of bees enhances their survival since humans (their predator) will mistake them for bees and avoid trying to catch or kill them.

Question 13

Resource partitioning is the result of

Accepted Answer

Resource partitioning occurs as a result of competition. In order to reduce competition for limited resources, species will adopt different strategies for resource use or occupy different niches, thus partitioning the available resources.

Question 14

Competitive exclusion is based upon the idea that

Accepted Answer

Competitive exclusion is the concept that no two species can completely occupy the same niche. This means that when two similar species compete for the same resources in the same habitat, one species will eventually outcompete and displace the other, causing the less fit species to either adapt or go extinct. This is due to limited resources and competition for those resources leading to the more efficient competitor winning out.

Question 15

A hummingbird that pollinates morning glory flowers and nests in the crotch of an apple tree. The apple tree is not harmed or helped by the hummingbird.  The relationship between the hummingbird and the apple tree is a

Accepted Answer

In commensalism, one species benefits while the other is neither helped nor harmed. In this scenario, the hummingbird benefits from the nectar of the morning glory flowers and uses the crotch of the apple tree for nesting, while the apple tree is not affected either way.

Question 16

Which of the following is NOT characteristic of parasites?

Accepted Answer

Parasites typically do not kill their hosts but rely on them for survival. Killing their host means the loss of their own habitat, food source, and reproductive environment. Many parasites have evolved mechanisms to ensure their host's longevity, so they can continue to thrive inside or on their hosts without disrupting their normal physiology or behavior. Therefore, inflicting serious injury or killing their hosts is not a typical characteristic of parasites.

Question 17

The interaction between two species in which both species may be harmed is known as

Accepted Answer

In competition, both species are harmed because they are both vying for the same limited resources.

Question 18

A relationship between two species in which both species benefit is known as

Accepted Answer

Mutualism is a type of relationship between two species in which both species benefit.

Question 19

The relationship between the yucca plant and the yucca moth that pollinates it is best described as

Accepted Answer

The relationship between the yucca plant and the yucca moth that pollinates it is an example of mutualism. The yucca moth benefits by laying eggs in the yucca flower, which provides food for its larvae, while simultaneously pollinating the plant. The plant benefits by receiving pollination services, which lead to the production of seeds. There is no evidence of parasitic or predatory behavior on either party, and commensalism (where one organism benefits and the other is neither helped nor harmed) does not fully describe the reciprocal benefits in this relationship.

Question 20

The mycorrhizal relationship you studied in a previous chapter is an example of

Accepted Answer

The mycorrhizal relationship is an example of mutualism, where both the fungus and plant benefit from their interaction, as the fungus provides nutrients to the plant while receiving carbohydrates in return.

Quiz 17: Communities and Ecosystems