CHAPTER 22 Test Your Knowledge

DRIVING QUESTION 1

What are keystone species in a community, and why are pollinators considered keystone species?

By answering the questions below and studying Infographics 22.1, 22.2, and 22.3, you should be able to generate an answer for the broader Driving Question above.

KNOW IT

How does a community differ from a population?

What are keystone species?

A rocky shoreline that is covered at high tide but exposed at low tide supports a community of mussels, algae, barnacles, and starfish. An ecologist systematically removes species from different areas of the beach. Removing the mussels doesn’t substantially change the community, but removing the starfish dramatically changes the mix of species in the area. Which is the keystone species?

a. mussels

b. barnacles

c. algae

d. starfish

e. all of the above

Bees transfer pollen from the________to the

a. anther; stigma

b. stigma; style

c. filament; ovary

d. anther; ovary

e. stigma; anther

USE IT

Think about a community of organisms that you are familiar with. From what you know about this community, choose what you think might be a keystone species and defend your choice.

If you have pollen allergies, are you more likely to be suffering from the effects of bee-carried pollen or wind-carried pollen? Explain your answer.

DRIVING QUESTION 2

What are food chains and food webs, and how does energy flow through them?

By answering the questions below and studying Infographics 22.4 and 22.5, you should be able to generate an answer for the broader Driving Question above.

KNOW IT

In relation to a food chain, what do plants and photosynthetic algae have in common?

a. nothing.

b. They are both producers.

c. They are both first level consumers.

d. They are both top level consumers.

e. Their numbers are limited by the energy they take in from heterotrophic food sources.

A bear that eats both blueberries and fish from a river can be referred to as

a. an omnivore.

b. a heterotroph.

c. a consumer.

d. a producer.

e. all of the above.

f. a, b, and c

g. a and c

USE IT

Describe a natural food web that includes a terrestrial food chain (including honeybees) and at least one aquatic organism from an aquatic food chain.

Explain how a cow can eat so many kilograms of grass but not produce the equivalent amount of energy in the form of meat. What happens to the energy stored in the grass once it is ingested by the cow?

Compare the diet of a human who is an herbivore with that of a human who is a top consumer. Consider what each might actually eat; how much energy from a producer is captured in the herbivore human; and how much energy from a producer is captured in the top consumer human.

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DRIVING QUESTION 3

What positive and negative interactions occur between members of a community?

By answering the questions below and studying Infographics 22.6, 22.7, 22.8, and 22.9, you should be able to generate an answer for the broader Driving Question above.

KNOW IT

What are some important features of a honey bee niche? How is it that other nectar-feeding organisms can coexist with bees as part of a community?

Competition is most likely to occur

a. when one species eats another.

b. when two species occupy different niches.

c. when one species helps another.

d. when two species occupy overlapping niches.

e. when two species help each other.

Which of the following characterizations best describes a symbiotic relationship?

a. Both organisms benefit.

b. The organisms live in close association.

c. Only one organism benefits.

d. The relationship is mutually harmful.

e. Neither organism benefits.

Would you characterize the relationship between the bacteria that live symbiotically within bees and their bee hosts as a type of competition, parasitism, mutualism, or commensalism? Explain your answer.

USE IT

On a rocky intertidal shoreline (the area between the highest and lowest tidelines, so the intertidal zone is alternately exposed and covered by seawater), mussels and barnacles live together attached to rocks where they obtain food by filtering it from ocean water. Since these two species coexist in the same habitat, we predict that they do not have identical niches. What might be separating their niches enough to allow them to occupy the same rocky intertidal zone?

If a meadow of wildflowers were converted to a field of corn, would you predict the number and diversity of bees in the community to increase or decrease? Explain your answer.

What is the evidence for and against each of the following being responsible for colony collapse disorder (CCD)?

a. varroa mites

b. IAPV

c. neonicotinoids

We all have E. coli bacteria living in our intestinal tracts. Occasionally these E. coli can cause urinary tract infections. From this information, which of the following terms would you say describe(s) the relationship between us and our intestinal E. coli? Why did you choose the term(s) you did?

a. competition

b. mutualism

c. parasitism

d. symbiosis

e. predator-prey

BRING IT HOME

Many people consider bees a stinging nuisance. What could you say to such people to dissuade them from killing all the bees in their backyards?

MINI CASE

Farmers often plant large acreage of a single crop in order to maximize yield and simplify harvesting. This is true of almonds in the central valley of California. a. From what you have read in this chapter, what are some of the pros and cons associated with monoculture?

b. Do some online research to develop a specific model for an alternative to monoculture that addresses at least one of the issues you have identified.

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INTERPRETING DATA

Scientists carried out an experiment to test the hypothesis that a neonicotinoid pesticide called imidacloprid could cause colony collapse disorder (CCD). They had a total of 20 hives (colonies) that were broken into 5 groups (with 4 hives per group). Four groups received imidacloprid at different dosages (400µg/kg; 200µg/kg; 40µg/kg and 20µg/kg). One group did not receive imidacloprid. Hives were monitored for 23 weeks after the initial dose. The data are summarized in the table below. a. Graph these data.

b. What patterns do you observe?

c. Do you think that the data support the hypothesis? Why or why not?