Ecosystem Interactions, Niches, and Population Dynamics in Biology

What is the difference between ecosystems and habitats?

Ecosystems are larger and comprise various habitats.

What is a niche in an ecosystem?

The role of an organism in the ecosystem, including its habitat and activities.

What factors are included in an organism's niche?

Both biotic factors (like food sources and predators) and abiotic factors (like temperature and sunlight).

What is competitive exclusion?

The extinction of a population due to direct competition with another species for resources.

What is the difference between a fundamental niche and a realized niche?

A fundamental niche is the theoretical niche an organism can occupy, while a realized niche is the niche it actually occupies.

What is niche diversity?

The number of different niches in an ecosystem, which supports different species.

What is a keystone predator?

A predator that helps promote greater niche diversity within an ecosystem.

Desert vs marshes available niches

In a marsh, few different niches hold lots of organisms. Desert hold few organisms, but lots of niches.

What is evolution in the context of ecosystems?

A change in the characteristics of a population of organisms over time, often in response to environmental changes.

Difference between fundamental and realized niche?

Fundamental niche is the niche an organism can occupy. Realized niche is the # of different niches in an ecosystem.

What is convergent evolution?

The independent development of similar adaptations in two species with similar niches.

What are generalized species?

Organisms with a wide niche, such as mice and raccoons.

What are specialized species?

Organisms with a small niche, such as koalas and pandas.

What are generalized species?

Organisms with a wide niche, such as mice, cockroaches, and racoons.

What is carrying capacity?

The maximum number of individuals of a species that an ecosystem can support.

What are density-dependent limiting factors?

Factors that are dependent on population size, such as food supply and disease.

What are density-independent limiting factors?

Limiting factors that affect the same percentage of the population regardless of size, such as natural disasters.

What is the J curve in population growth?

A growth curve that shows exponential growth without limits.

What is the S curve in population growth?

A growth curve that shows population growth that levels off as it reaches carrying capacity.

What factors can limit population growth?

Climate, human disturbance, predation, natural disasters, water availability, living space, food competition, disease, and parasitism.

How do abiotic factors influence niche diversity?

Great differences in abiotic factors lead to more niche diversity in an ecosystem.

Do variations in habitat cause more or less niches and why?

Would cause more niches because it would allow species to specialize in different ways.

How does population growth affect resource competition?

As populations grow, they compete more for limited resources, leading to increased death rates and decreased birth rates.

What happens when an organism moves into another organisms niche?

Causes niche overlap which in turn causes shared limited resources, potentially causing one species to outcompete and eliminate the other (competitive exclusion)

What is the role of abiotic factors in determining niches?

Abiotic factors like temperature and precipitation create different niches for various species.

What is an example of a biotic factor in a niche?

Food sources and predators.

What is an example of an abiotic factor in a niche?

Temperature or the amount of sunlight.

Difference between convergent and coevolution?

Convergent -The independent development of similar adaptations in two species with similar niches.

Coevolution - The process by which species interact so closely with one another that they adapt to one another.

Reason for competition between organisms

Limited resources

Carrying capacity

Is the maximum population size of a species that an environment can sustainably support over time

Reason for boom and bust population

Happens because periods of rapid economic growth (booms) fueled by easy credit and overinvestment eventually lead to unsustainable projects, causing a sharp downturn (bust) as confidence drops, leading to spending cuts, layoffs, and a contraction before recovery begins again.

Factors that allow human populations to continue to grow exponentially

Advances in agriculture

Technology

Energy Development

Transportation

Medicine

Niche

the role of an organism in an ecosystem.

Predator

An organism that actively hunts other organisms.

Prey

An organism upon which an organism feeds.

Evolution

A gradual change in a population of organisms over-time.

Exponential growth

Population growth in which the rate of growth in each generation is a multiple of the previous generation.

Density-dependent limiting factor

A limiting factor that is dependent on population size.

Density-independent limiting factor

A limiting factor that affects the same percentage of a population regardless of its size.