Exam 47: Species Interactions, Communities, and Ecosystems

The volcanic oceanic island of Krakatoa is located in Indonesia. In 1883, this island experienced a massive volcanic explosion that killed most of the plants and animals living on the island. After a very, very long time period of recovery from the eruption, which group of organisms would we expect to have the MOST representation among native species on the island?

The presence of bacteria that produce essential amino acids in the bodies of aphids is an example of:

A paleontologist is trying to understand the niche of Triceratops during the Cretaceous Period. What could she study to characterize the niche of the Triceratops?

You sample the solid waste of three infants from three different families each week for 24 weeks. You find that the gut bacteria population is dominated by one species for the first 12 weeks, and then shifts to another species. Which of the following might be a major factor in this change?

Small, photosynthetic algae called zooxanthellae inhabit organisms such as corals and anemones, and provide these organisms with food, while acquiring a protected environment in which to live. This is an example of:

Your summer garden did very well, but over the winter your hibiscus plants that attracted so many hummingbirds the first year, were killed by cold winter temperatures. You are so annoyed that you ignore the garden; much to your surprise sunflowers sprout on their own. That second summer you see lots of goldfinches (small yellow birds) visit the garden to eat the sunflower seeds. Given that all abiotic conditions remained the same over the 2 years, why do you see hummingbirds the first year and goldfinches the second year?

Typically when a keystone species is removed from a community:

A species that is involved in a facultative mutualism with another:

An ecological _____ is the set of all populations of all species found in a given place.

In general a larger biomass in primary producers for a trophic pyramid:

Imagine you are studying a forest community that is subject to unusually intense fires and hurricanes approximately every 100 years, which is more frequently than in most environments. What would you expect of the species diversity in this community?

What is generally true about biomass and energy as we move from one trophic level to the next?

Some argue that any members of the microbiota that take up space on our body surfaces and do no harm to us are actually providing us a service because they prevent the colonization of harmful species. From this point of view, the relationship between the skin microbiota and their human host is:

Tropical leafcutter ants collect leaf cuttings which they transport to special underground chambers. There, they chew the leaves to create nursery beds on which they grow a species of fungus they use for food. When ant queens disperse to establish new colonies, they carry the fungus with them, dispersing it as well (this benefits the fungus). In the ants' nest, the fungus is at risk of being destroyed by another fungal species that is able to grow in the same habitat, using the same limited resources. On their bodies, the ants carry and provide a home for bacteria that produce antibiotics the ants use to kill this second fungus and thereby protect their food supply. In this system, the relationship between the two fungal species is:

Which group in a food web is responsible for returning inorganic compounds back to the environment?

In the Sierra Nevada mountains of California there are many populations of the checkerspot butterfly, Euphydryas editha. The young of both populations hatch out as caterpillars; they live on the host plant and eat the new leaves. The host plant used by population A grows over a single season, with new leaves (the most nutritious) appearing at the tip of the stem. Where do you expect females from population A to lay their eggs?

Which of the following BEST describes the kind of resource for which individuals may compete?

When two species compete for resources, the fitness of:

Depletion of a resource by one species, which lowers the availability of that resource to other species, is an example of:

Measuring its costs and benefits in terms of energy spent and/or gained, predation: