Biology: Exam 5 (E3)

Food web

A complex interconnection of feeding relationships in a community.

Community

A group of interacting populations of different species living together in the same area.

Food chain

A linked series of feeding relationships in a community in which organisms further up the chain feed on ones below.

Symbiosis

A relationship in which two different organisms live together, often interdependently.

Mutualism

A type of symbiotic relationship in which both members benefit; a "win-win" relationship.

Commensalism

A type of symbiotic relationship in which one member benefits and the other is unharmed.

Parasitism

A type of symbiotic relationship in which one member benefits at the expense of the other.

10 million

About how many species of living things are estimated to be present on Earth?

1.7 million

About how many species of living things have been described on Earth?

Competition

An interaction between two or more organisms that rely on a common resource that is not available in sufficient quantities.

Predation

An interaction between two organisms in which one organism (the predator) feeds on the other (the prey).

They eat producers.

Are consumers above or below producers in the food chain?

Producers

Autotrophs (photosynthesis organisms) that form the base of every food chain.

Producers obtain energy from the sun. Consumers obtain energy by feeding on other organisms. Herbivores obtain energy by eating plants and are energy for producers.

Briefly explain how an energy pyramid shows the flow of energy up a food chain.

The timescales involved cancel out any benefits they might experience from the rising temperatures - millions of years needed to get the benefit.

Current estimates, based on current destruction patterns, indicate that the Earth will lose the tropical rainforest ecosystem in about how many years?

Home too more than half (>50%) of the world's species of life.

Even though it only makes up 2% of the Earth's surface, about what percent of all life is found in tropical rainforests?

Habitat destruction, Pollution, Overexploitation, and Competition & predation from introduced species.

Explain how something can be rare but not endemic.

Trophic levels

Feeding levels, based on positions in a food chain.

Rare is not the same as endangered - many species occur in very small numbers normally but they may not be in danger of extinction.

Give an example of an invasive species found in Kentucky.

Consumers

Heterotrophs that eat other organisms lower on the food chain to obtain energy.

Organisms in a food chain can be categorized by who eats whom.

How are organisms in a food chain categorized?

A community is a collection of interacting populations of different species in a given geographic area. A population is a group in interbreeding organisms of the same species in a given geographic area.

How does a community differ from a population?

50-100 years.

If warm temperatures lead to the greatest biodiversity, why is global warming such a bad thing for so many species?

Herbivory

Predation on plants, which may or may not kill the plant preyed on.

Keystone species

Species in which other species depend, and whose removal has a dramatic impact on the community.

Niche

The space, environmental conditions, and resources that a species needs in order to survive and reproduce.

An example of a keystone species in Kentucky is the beaver.

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.

Keystone species are species that have strong influence on the community, without necessarily having a high abundance.

What are keystone species?

Honeysuckle.

What are the 4 main causes of the decline of biodiversity?

Passenger pigeon and the Carolina parakeet.

What are two extinct species whose last known members died at the Cincinnati Zoo?

They have no natural predators and are not generally eaten by anything else in the community.

What is an advantage to being a top consumer?

No two species can successfully coexist in identical niches in a community because one would eventually out-compete the other—a concept described by the competitive exclusion principle.

What is the competitive exclusion principle?

Harder to obtain energy necessary to live.

What is the disadvantage to being a top consumer?

Coral reefs.

What is the most diverse ecosystem of the oceans?

They are higher on the food chain.

What is the prey of herbivores?

Plants.

Where do consumers get their energy (food)?

Directly from the sun.

Where do producers get their energy (food)?

Diversity of most groups is greatest in tropics.

Where is biodiversity greatest?

The food chain is oversimplified. Many organisms are omnivores (that is, they eat both plants and animals) and so occupy more than one position in the chain.

Why is a food web a better representation of feeding relationships in a community than a food chain?

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.

b. The organisms live in close association.

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.

b. They are both producers.

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

d. starfish

Competition is most likely to occur a. when one species eats another. b. when two occupy different niches. c. when one species helps another. d. when two species occupy overlapping niches. e. when two species help each other.

d. when two species occupy overlapping niches.

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

f. a, b, and c.