Exercise 15 Flashcards
What is the difference between mutualism and commensalism?
Mutualism is a mutually beneficial interaction whereas commensalism is an interaction in which one species benefits and the other species may be harmed.
Mutualism is a mutually beneficial interaction whereas commensalism is an interaction in which one species benefits and the other species does not benefit and is not harmed.
Mutualisms are symbiotic whereas commensalisms are non-symbiotic.
None of the above
Mutualism is a mutually beneficial interaction whereas commensalism is an interaction in which one species benefits and the other species does not benefit and is not harmed.
In which of the following cases could positive interactions evolve over time?
The costs of the interaction consistently outweigh its benefits.
The costs and benefits of the interaction are the same for both species.
The benefits of the interaction consistently outweigh its costs.
A symbiotic mutualism switches to a parasitism.
The benefits of the interaction consistently outweigh its costs.
Both competition and facilitation are important in
species interactions such as those between ants and fungi or cockroaches and protists.
plant species that interact at low mountain elevations.
plant species that interact at high mountain elevations.
plant species that interact at high and low mountain elevations.
plant species that interact at high and low mountain elevations.
Which of the following characterizes mutualisms?
Both partners can provide habitat.
Both partners can provide pollination.
One partner can provide food and the other can provide habitat.
One partner can provide food but the other partner provides nothing.
One partner can provide food and the other can provide habitat.
Ants form mutualisms with treehoppers. Which is true about this interaction?
Ants protect treehoppers from predators.
Treehoppers protect ants from predators.
Treehoppers modulate their secretion of honeydew when predators are low.
Ants modulate treehopper honeydew secretions when predators are low.
Ants protect treehoppers from predators.
Why is there a conflict of interest between the partners in a mutualism?
They are always altruistic.
The benefits provided by each species come never come at a cost.
Natural selection favors cheaters but also rewards for overexploiting a partner.
Natural selection favors cheaters but also penalizes for overexploiting a partner.
Natural selection favors cheaters but also penalizes for overexploiting a partner.
How can positive interactions affect the distribution and abundance of species?
By affecting the growth of one or the other species
By affecting the reproduction of one or the other species
By affecting the survival of one or the other species
All of the above
All of the above
How can a facilitator increase species richness in communities?
A facilitator can benefit a dominant species that, in turn, benefits other species.
A facilitator can directly compete with other species.
A facilitator can benefit a dominant species that, in turn, negatively affects other species.
A facilitator can compete with another facilitator species that, in turn, negatively affects other species.
A facilitator can benefit a dominant species that, in turn, benefits other species.
What type of mutualistic interaction has been shown to have effects on nutrient cycling?
Yuccas and yucca moths
Acacia trees and acacia ants
Reef fishes and cleaner fishes
Plants and mycorrhizal fungi
Plants and mycorrhizal fungi
In comparing agriculture practiced by humans and by leaf-cutter ants, which of these statements is the least correct?
Both groups grow crops, benefiting themselves and the crop species.
Both groups are highly dependent on food produced through agriculture.
Both groups have been practicing farming for about the same length of time.
Agriculture has allowed both groups to develop extremely high populations.
Both groups have been practicing farming for about the same length of time.
A bird species nests in a specific kind of tree. The tree is not harmed by the bird building its nest in the tree’s branches, but the bird benefits from the shelter provided by the tree and is better able to successfully raise young. This is an example of ____.
mutualism
endosymbiosis
commensalism
symbiosis
commensalism
Which criterion is most important in determining whether an ecological relationship is a symbiosis?
Whether both parties benefit
Whether the parties are evolutionarily closely related to each other
The degree of physical proximity between the two parties
The number of parties in the interaction
The degree of physical proximity between the two parties
An ant colony maintains and farms a species of fungus on which it feeds. The fungus, in turn, is parasitized by a bacterium. The ant/fungus interaction is _______ and the fungus/bacterium is _______.
+/+; +/-
+/0; +/-
+/+; +/0
+/0; +/+
+/+; +/-
Refer to the table.
Year Fungus upper Fungus lower Host upper Host lower
1987 65 54 –7 –21
1990 63 47 –2 –9
1993 70 54 –3 –8
1996 67 52 5 –4
1999 64 49 15 3
2002 71 55 22 8
2005 68 54 20 9
The table contains data on the effects of symbiosis between a fly (host) and a fungus over many years. It shows the upper and lower bounds for the effects of the association; positive numbers denote net benefits and negative numbers denote net costs. (If zero is between the upper and lower bounds, consider the effect to be zero, since it is statistically indistinguishable from zero.) According to the table, the relationship between the fungus and the fly in 1990 was a ____.
mutualism
competitive interaction
commensalism
host‒parasite interaction.
host‒parasite interaction.
All other factors being equal, which scenario is least likely to involve coevolution?
An obligate positive interaction in which one party lives inside the other
An obligate positive interaction in which the two parties benefit each other
An obligate positive interaction in which one party consume the other
A facultative interaction in which the two parties are from different kingdoms
A facultative interaction in which the two parties are from different kingdoms
