When designing an experiment, the first step is to ___.

A standard for comparison that helps to ensure that the experimental result is caused by the condition being tested is the ________.

A factor that changes in an experiment from manipulation of the independent variable is the _____.

A factor that does not change in an experiment is the ______.

An organized process used to gather observations and test a hypothesis is a(n) ____.

A statement that describes what happens in nature is a _______.

An explanation of an event that is based on repeated observations and experiments is a _____.

An idea, event, or object that can be used to represent something you are trying to explain is a ___.

In an experiment to determine if the popping of popcorn is affected by the temperature at which it is stored, counting the popped kernels is an example of a(n) _______.

A measurement standard is defined as _____.

The correct symbol for the SI unit of temperature is ___.

In a graph, the variable on the horizontal axis is the ____.

The type of graph that would be used to show how some fixed quantity is broken down into parts is a ___.

In a graph showing how the temperature of a material changes over time, temperature change is the ____.

A unit of measurement that is obtained by combining other units is a _____ unit.

Of the following, the most correct way to express density is _____.

Of the following, the only unit that cannot be used to express volume is _____.

450 mg is equal to ________________ g.

57.55 L is equal to __________mL.

6.89 km is equal to ___________ m.

_____ is the study of living things

People who obtain food by collecting plants and by hunting wild animals or scavenging their remains are known as ___________.

The plants that we grow and eat today are descended from __________.

Raising crops and livestock for food or for other products that are useful to humans is known as _________.

______ is the study of chemicals and their interactions.

Giant sloths, giant bisons, mastadons, cave bears, and sabre toothed cats are all animals that disappeared because of overhunting by _________.

Who can be classified as a nonscientist?

_________ is the study of interactions of living organisms.

The study of air, water, and land surrounding an organism or a community, which ranges from a small area to Earth's entire biosphere.

The _______ involved a shift from energy sources such as animals and running water to fossil fuels such as coal and oil.

_______ is the study of matter and energy.

Environmental problems can generally be grouped into three categories: Resource Depletion, ____, and Loss of Biodiversity.

The ____ introduced many positive changes such as the light bulb.

____ has higher incomes, slower population growth, diverse industrial economies, and stronger social support.

A _____ balances the cost of the action against the benefits one expects from it.

Resources are said to be ____ when a large fraction of the resource has been used up.

______ is the condition in which human needs are met in such a way that a human population can survive indefinitely.

_____ means can be broken down by natural processes and include materials such as newspapers.

___ means cannot be broken down by natural processes and includes materials such as mercury.

_____ is a law of economics that states as the demand for a good or service increases, the value of the food or service also increases.

____ has lower average incomes, simple agriculture-based communities, and rapid population growth.

_______ can be replaced relatively quickly by natural process.

Agricultural productivity increased and sanitation, nutrition, and medical care vastly ______.

_______ form at a much slower rate than they are consumed.

_______ is any natural materials that are used by humans, such as, water, petroleum, minerals, forests, and animals.

The ____ is the thin and solid outermost layer of the Earth above the mantle.

_____ is a gas molecule that is made up of three oxygen atoms.

The ___ is the warming of the surface and lower atmosphere of Earth that occurs when carbon dioxide, water vapor, and other gases in the air absorb and reradiate infrared radiation.

____ makes up 78 percent of the Earth’s atmosphere, and enters the atmosphere when volcanoes erupt and when dead plants and animals decay.

____ is the second most abundant gas in the atmosphere and is primarily produced by plants.

The ___ is the layer of the atmosphere that lies immediately above the troposphere and extends from about 10 to 50 km above the Earth’s surface.

The lower thermosphere is called the _____.

The layer above the stratosphere is the _______.

The most abundant greenhouse gases are ______, although none exists in high concentrations.

The mesosphere is the ___ of the atmosphere where temperatures have been measured as low as -93℃.

The measure of the energy released by an earthquake is called ______.

The ____ is the layer of rock between the Earth’s crust and core.

A ____ is a mountain built from magma, or molten rock which rises from the Earth’s interior to the surface, and can occur on land or in the sea.

The ____ is the solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle.

A ____ is a break in the Earth’s crust along which blocks of the crust slide relative to one another.

The ____ is the part of the Earth where life exists.

The _____ makes up all of the water on or near the Earth’s surface.

The ___ is the part of Earth where life exists, extending about 11 km into the ocean about 9 km into the atmosphere.

The ___ is the third largest ocean on Earth with a surface area of 73,420,000 km ² .

_____ is a measure of the amount of dissolved salts in a given amount of liquid.

___ are stream-like movements of water that flow very slowly along the ocean floor.

___ is any form of water that falls to the Earth’s surface from the clouds, and includes rain, snow, sleet, and hail.

The smallest ocean is the ____, which covers 14,350,000 km ².

The largest ocean on Earth is the ____ with a surface area of about 165,640,000 km ² .

____ is the change of a substance from a liquid to a gas.

The second largest ocean on Earth is the ____, and has a surface area of about 81,630,000 km².

____ is the change of state from a gas to a liquid.

The first vertebrates were ______.

____ are extremely small, single-celled organisms that usually have a cell wall and reproduce by cell division.

What are the two kinds of bacteria?

_____ are animals that do not have backbones.

Flowering plants that produce seeds within the fruit.

_____ are animals that have a backbone, and includes mammals, birds, reptiles, amphibians, and fish.

The most important protists are _____.

More ____ exist on Earth than any other type of animal.

The first land vertebrates were _____.

______ was an English naturalist that observed that organisms in a population differ slightly from each other in form, function, and behavior.

___ is the selective breeding of organisms, by humans, for specific desirable characteristics.

____ are places where organisms usually live.

____ are communities of organisms and their abiotic environment.

____ are groups of organisms of the same species that live in a specific geographical area and interbreed.

Most of the energy of an ecosystem comes from the _____.

_____ are living things that can carry out life processes independently.

Species that colonizes an uninhabited area and that starts an ecological cycle in which many other species become established.

The first pioneer species that colonized bare rock.

The movement of carbon from the nonliving environment into living things and back.

Formed when nitric oxide combines with oxygen and water vapor.

Nitrogen makes up ____ of the gases in the atmosphere.

Coal, oil, and natural gas are known as ___.

A consumer that eats another consumer.

Eat both plants and animals.

Eat only plants.

Producers are also called _____.

Consumers are also called _______.

Eat dead organic matter.

Eat only animals

A tree that has seeds that develop in cones.

The ___ is the layers of treetops that shade the forest floor, and is considered to be the primary layer of the rain forest.

The ___ is the region of evergreen, coniferous forest below the arctic and subarctic tundra regions.

The ____ is the foliage layer that is beneath and shaded by the main canopy of a forest.

The three main forest biomes of the world.

Forests or jungles near the equator.

The main layers of the rain forest are ___, ___, ___, and the ____.

The average weather conditions in an area over a long period of time.

The height of an object above a reference point, such as sea level or the Earth’s surface.

The distance north or south from the equator, and is expressed in degrees.

Each biome is made up of many individuals ______.

Most animals in the desert are _____, meaning they are active mainly at night or dusk when its cooler.

Covers vast areas of rocks in the tundra.

A common adaptation of chaparral is _____, shape or coloring that allows an animal to blend into its environment.

The permanently frozen layer of soil or subsoil can be found in the tundra regions.

Regions that have little or no vegetation, long periods without rain, and extreme temperatures.