Chapter 4 Part 1: The Living World: Ecosystems and Biodiversity

Plants

________ and animals that reside in the littoral zone receive abundant sunlight.

symbiotic relationships

In commensalism ________ (commensalism), one organism benefits while the other is neither helped nor hurt.

freshwater bodies

Like ________, oceans are divided into zones based on changes in light and temperature.

Mangroves

________ are characterized by trees, shrubs, and other plants that can grow in brackish tidal waters and are often located in estuaries, which, as you learned earlier, are areas where freshwater meets salt water.

Genetic drift

________ is the accumulation of changes in the frequency of alleles over time due to sampling errors- changes that occur as a result of random chance.

North America

In ________, mangrove swamps are found from the southern tip of Florida along the entire Gulf Coast to Texas; Floridas southwest coast supports one of the largest mangrove swamps in the world.

Littoral zone

________: Begins with the very shallow water at the shoreline.

Algae

________ in marine biomes supply a large portion of the Earth's oxygen, and also take in carbon dioxide from the atmosphere.

Earth

When precipitation falls onto the ________, it may infiltrate the surface and percolate through soil and rock until it reaches the water table to become groundwater, or it may travel across the land's surface as runoff and enter a drainage system, such as a stream or river, which will eventually deposit it into a body of water such as a lake or an ocean.

Predation

________ occurs when one species (a predator) feeds on another (prey), and it drives changes in population size.

Lakes

________ and oceans are reservoirs for water.

Biodiversity

________ in all forms is the result of evolution.

Phylogenetic trees

________ can be very broad and encompass many types of species, or they could be very specific and describe the evolutionary relationships that exist between two species (or even the genome of one species.

Ecosystems

________ are the result of the biotic and abiotic components interacting.

Grand Banks

Commercial or economic extinction is when a few individuals exist but the effort needed to locate and harvest them is not worth the expense (for example, the groundfish population of the ________ off the Maritimes of Canada)

barrier islands

Because ________ are created by the buildup of deposited sediments, their boundaries are constantly shifting as water moves around them.

physical surroundings

When a habitat (an organism's ________) selects certain organisms to live and reproduce and others to die, that population is said to be undergoing natural selection.

micro evolution

When a population displays small- scale changes over a relatively short period of time, ________ has occurred.

calciferous shell

The organisms responsible for the creation of coral reefs are cnidarians, which secrete a hard, ________; these shells provide homes and shelter for an incredible diversity of species, but they are also extremely delicate and thus very vulnerable to physical stresses as well as changes in light intensity, water temperature, ocean depth, and pH.

total genetic makeup

What changes during evolution is the ________ of the population or gene pool, and natural selection is one of the mechanisms by which evolution operates.

Coral bleaching

________ occurs when acidic conditions cause the coral to expel the colorful algae which provided them with food.

water cycle

In the ________, water might exist in the form of a cloud for a few days, but it might exist as part of the ocean for a thousand years.

Extinction

________ occurs when a species can not adapt quickly enough to environmental change and all members of the species die.

community of living organisms

An ecosystem is a system of interconnected elements: a(n) ________ and its environment.

Bathyal zone

________: The middle region; is colder and darker and does not receive enough light to support photosynthesis, so the density of organisms that live there is less.

Evolution

________ is the change in a populations genetic composition over time.

clown fish

The ________ protects the sea anemone from some of its predators, while the stinging cells of the anemone protect the clownfish; the fish also eats some of the detritus left behind when the anemone feeds.

Coastal zone

________: This zone consists of the ocean water closest to land.

Ocean

The increase in ________ temperatures and dissolved CO, due to climate change is resulting in more acidic waters resulting in coral bleaching.

Biotic components

________- life- require resources to flourish, and the availability of those resources influences the interactions between species and their interactions with the environment over time the most influential fundamental interaction between and among ecosystems is that of evolution- which produces life as we know it.

Land environments

________ are separated into biomes based on factors such as climate, geology, and soils.

Biological extinction

________ is the true extermination of a species.

Benthic zone

________: The surface and sub- surface layers of the river,- lake,- pond,- or stream bed, characterized by very low temperatures and low oxygen levels and inhabited by organisms that live on, in, or below the sediment surface, including bottom- feeders, scavengers, and decomposers (including microorganisms such as bacteria and fungi)

Abyssal zone

________: This is the deepest region of the ocean.

Then well examine the biotic components of ecosystems

living systems -and how energy is used among them

An ecosystem is a system of interconnected elements

a community of living organisms and its environment

Strictly speaking, a species is defined as a group of organisms that are capable of breeding with one another

and incapable of breeding with other species

These breeding variances could be a result of a chance event

such as an earthquake that drastically reduces the size of the nesting population one year

Some species interact quite a bit with other members of their population; for example, some animals form herds, while other species are loners

like bears

Competition arises when two individuals of the same species or of different species

are competing for resources in the environment

The resources that are competed for can be food, air, shelter, sunlight, and various other factors necessary for life

individuals may be competing to live in a fallen tree, to catch a running rabbit, or to mate with the most desirable female in the population

That's right

the others are eliminated by competition

One more thing about competition

when two different species in a region compete and the better-adapted species win, this phenomenon is called competitive exclusion

They can coexist because each species feeds in a different part of the tree

the trunk, at the ends of the branches, and at other sites

Keep in mind that many types of species can engage in both short

and long-term migration, for reasons including food and water availability, temperature changes, mating opportunities, and safety from predation

As a final note about predation

while it's tempting to think of predation existing only between animals, remember that herbivores prey on plants and Zooplankton on phytoplankton

In mutualistic symbiotic relationships (mutualism), both species benefit

for example this type of relationship exists between sea anemones and clown fish

The two largest categories are broken down in this way

ecosystems that are based on land are called biomes, while those in aqueous environments are known as aquatic life zones

The transitional area where two ecosystems meet actually has a name

these areas are called ecotones

Another important term that you should be familiar with for the exam is ecozones

ecozones (also called ecoregions) are smaller regions within ecosystems that share similar physical features

Recall that aquatic life zones are the equivalents of biomes in aquatic ecosystems categorized primarily by the salinity of their water

freshwater and saltwater ecosystems fall into separate categories

Littoral zone

Begins with the very shallow water at the shoreline

Benthic zone

The surface and sub-surface layers of the river-, lake-, pond-, or stream bed, characterized by very low temperatures and low oxygen levels and inhabited by organisms that live on, in, or below the sediment surface, including bottom-feeders, scavengers, and decomposers (including microorganisms such as bacteria and fungi)

Coastal zone

This zone consists of the ocean water closest to land

Euphotic zone

The photic, upper layers of water

Bathyal zone

The middle region; is colder and darker and does not receive enough light to support photosynthesis, so the density of organisms that live there is less

Abyssal zone

This is the deepest region of the ocean

Now that we've outlined what the major biomes and aquatic life zones look like, let's take some time to discuss the abiotic elements of ecosystems

specifically, the elements that bridge the gap between the nonliving and the living-water, nitrogen, carbon, and phosphorus they cycle through the environment, bringing the key components that ecosystems need to function and burgeon with life

The energy that drives these biogeochemical cycles in the biosphere comes primarily from sources

the sun and the heat energy from the mantle and core of the Earth

Let's start with perhaps the best-known biogeochemical cycle

the water cycle