To calculate the relative age of rocks, geologists use the rate of radioactive decay of isotopes present in their samples. What is the term used for the original amount of the elemental isotopes being investigated?

If a metamorphic rock contains an intrusion of igneous rock, which rock is the oldest?

Scientists can use relative dating, absolute dating, or a combination of the two techniques to determine the age of a fossil. Which of the following could be determined using both methods?

Several zircon crystals from Australia have been dated to have an estimated age of 4.2 billion years. Which statement BEST describes the period of formation of these crystals?

Fossils of Haikouella were discovered in 1999. The fossils are thought to be about 530 million years old. The Haikouella is an example of an early vertebrate, but it appears to be lacking a braincase. Modern vertebrates have a braincase. Which is theMOST likely evidence these fossils provide?



The ichthyornis was a type of bird that lived over 65 million years ago. It lived near the sea and hunted for fish over the water. Fossils have been found in Kansas, many miles from the present-day ocean. Which cause of extinction is MOST likely to be found in the fossil record along with ichthyornis fossils?

Thousands of fish fossils discovered high in the Rocky Mountains MOST likely indicate that

A student has made the geologic column below. What evidence must be carefully examined to determine that organisms changed over time?

Several dinosaur bones are discovered buried in volcanic ash. The type of dinosaur can BEST be identified by

The map shows bodies of water associated with North America. Which of the following bodies of water shown on the map would leave a salty layer on your skin if you swam in it?

The graph shows the distribution of the freshwater resources of Earth.

Which of these sources of fresh water corresponds to Source 1?

Which type of water reservoir could always provide fresh water?

The water cycle describes the movement of water on Earth. About 96% of water on Earth is the salt water found in oceans. The remaining 4% is fresh water. Where would the majority of the fresh water on Earth be found?

The figure below shows the average water speeds in four sections of a river. The speeds are expressed in centimeters per second (cm/s).

Which section would MOST likely be able to move the largest particles?

Which technology is most efficient in mapping large areas of the ocean floor?

Which contributes most in supporting life on the deep ocean floor?

Which technique uses sound waves to measure the depth of the ocean floor?

In which location would fishermen most likely catch a greater number of fish?

Oceans cover about 70% of the surface of the Earth and form layers based on water depth. Which best describes a factor that is the same for the different layers of the oceans?

Fish, flies, and algae are bioindicators known to exist in a certain North Carolina river. Recently a chemical company was built upstream. Which environmental factor is most likely measured by these bioindicators in this river?

Why do biologists use indicator species?

Which environmental factors would mostlikely impact the quality of a freshwater system?

Which would most affect the health of fish in a local pond?

After analyzing data collected from a pond, there is a significant decrease in dissolved oxygen. Which most likely caused the decline?

Which most likely would cause diseases to be spread by polluted water?

Which is most likely an example of point source pollution?

Which is an effect of chlorine in water?

Which are two factors that affect water quality?

Which factors can have the greatest effect on the health of a river system?

Which of these is an abiotic element of a desert ecosystem?

One male and one female goldfish are placed into a 5-gallon aquarium and are fed each day. One male and one female goldfish are placed into a 10-gallon aquarium and are fed each day. Whichmost likely represents the number of goldfish in each aquarium after several months?

Which interaction between animals BEST controls the population of a species?

Multiple Choice from Item CentralAs populations grow, they need more resources, such as food. But Thomas Robert Malthus claimed that human populations and the resources they need increase at different rates. The graph below illustrates his theory.

What is happening at Point A?

A large quantity of heavy rain falling in a short time period will MOST likely

Which best describes mutualism?

As a dog walks through thick brush, a tick attaches to its leg. Which best describes the relationship between the dog and the tick?

Which is an example of parasitism?

Kudzu vines grow by climbing and wrapping around trees. Trees covered by kudzu can die because they are starved of sunlight. What type of relationship exists between the trees and the kudzu growing on them?

Which of these organisms is a producer in a marine ecosystem?

Radioactive waste from nuclear power plants is sealed in containers and deeply buried in the ground. Sealing and burying waste reduces the chances that water will become contaminated. At which point in the water cycle would radioactive contamination MOST likely be found?

In an ecosystem, not all of the energy that is available is used by the organisms. Some energy becomes unavailable before it can be transferred to organisms in the next trophic level. How does the energy MOST likely become unavailable?

When animals break down glucose to create energy, they release water and carbon dioxide (CO2.) How can carbon dioxide (CO2) be reused within the food web?

Some bacteria, fungi, and insects can decompose other organisms. Which BEST describes the role of insects in the decomposition process?

Near Earth’s equator, water generally exists naturally in the liquid and gas states. In which other part of Earth is water usually found naturally in only two states?

Greenhouse gases are often produced as a result of obtaining and using fossil fuels. Which greenhouse gas most likely has the greatest impact on global warming?

How has burning fossil fuels MOST caused a decline to the quality of air that people breathe?

Which of these human activities MOST likely helped in depleting the ozone layer?

Which of the following is an example of how the production of hydroelectric power could potentially harm the environment?

Why is solar energy seldom used as an environmentally safe energy source in households to provide electricity?

Some regions produce large amounts of geothermal energy. This energy production indicates that the crust in these regions

Compared to similar-sized gasoline-powered vehicles, electric-gasoline-hybrid vehicles are primarily designed to

Which upgrade to a school will most likely reduce the school’s consumption of nonrenewable resources?

Why is it important to limit the use of fossil fuels such as coal and natural gas?

Which best describes a renewable energy source?

This diagram represents a classification of living organisms.

Which word is the BEST title for this diagram?

Which would indicate that a series of fossils represent the evolution of the horse?

Millions of years ago, four aquatic organisms died, and their remains came to rest on Earth’s surface beneath the water.

Organisms are classified into three domains:

1. Archaea

2. Bacteria

3. Eukarya

Organisms can reproduce with spores in

Which best explains why the wing of a bat and the fin of a whale are similar?

A new predator has just moved into an area with a population of rabbits. The rabbits with longer back legs have an advantage because they can run faster. Which is an example of adaptation?

Charles Darwin made famous observations of finches on islands in the Pacific Ocean. The birds were believed to have come all from one population, but when separated on the islands with differing habitats, the birds changed. The beaks of the birds on islands with lots of seeds were different from the beaks of the birds on islands with lots of insects. How did their beaks come to match the food in their environments so well?

Which would best allow a species to survive environmental changes?

A low-level species in a food web suddenly becomes extinct. Of its predators, which will most likely survive?

Scientists estimate that whaling activity in the 19th and early 20th centuries had reduced the number of adult female southern right whales to as few as sixty individuals by 1920. This reduction resulted in a genetic bottleneck for the species.

Treaties to stop whaling have substantially increased the number of southern right whales. Despite this increase, the bottleneck still threatens the future of the species. Which capacity of the species is MOST severely diminished by the bottleneck?

Which of the following results when hydrogen and chlorine chemically bond to form hydrogen chloride?

An element is identified by

What number and types of atoms occur in a formula unit of Ca(NO₃)₂?

An element, X, contains 14 protons, 15 neutrons, and 14 electrons. Which is most likely the same element as X?

How are atoms combined in a mixture?

What physical property is characteristic of all of the elements in the group located in the rightmost column of the periodic table?

Which statement BEST describes the organization of the periodic table of the elements?

Sodium (Na) reacts with water. Which element is most likely to have a similar effect to sodium if it is exposed to water?

Which subatomic particles determine the reactivity of groups of elements in the periodic table?

Which pair of elements has the most similar properties?

Which statement BEST describes the formation of rust?

When iron combines with oxygen in a moist environment, rust forms because of a

Some power plants produce energy by burning coal. In these power plants, the heat from burning coal is used to boil water. Which statement BEST describes the changes that occur when burning coal and boiling water?

What happens to water molecules during the boiling process?

An ice cube is put into a heated pan. What will most likely happen to the molecules in the ice as the ice is heated?

Which is best represented by the equation?

2Mg + O₂ 2MgO

Which set of coefficients will balance this chemical equation?

__C₂H₄(g) + __O₂(g) → 2CO₂(g) + 2H₂O(g)

If 100 grams of vinegar and 5 grams of baking soda are poured in a container, a small amount of gas will be produced. What will the final mass of the products be if the gas is trapped in the container?

The chemical equation below shows reactants and products.

Which statement is BEST supported by analyzing this equation?

If a chemical reaction such as photosynthesis begins with 6 atoms of carbon (C), how many atoms of carbon (C) should be in the products?

Which two statements in the table are true for plant cells and FALSE for animal cells?

Which food items can be broken down mostly into amino acids?

A lion and a crocodile are both large animals, but a lion has to eat much more than a crocodile of the same mass to survive. Which statement BEST explains the difference?

How are bacterial cells and human cells alike?

After a person eats, the food is converted into energy by

Which statement BEST describes why a calcium-fortified juice would advertise that it is good for growing children?

Why is a healthy diet important?

Which technology enables doctors to monitor the function of the heart?

Which food provides the most energy for the body in the shortest amount of time?

Which best describes the relationship between digestion and respiration?

Which of these conditions MOST likely results from infection?

HIV is a retrovirus. Which sequence does it use as part of its reproductive cycle?

Why are viruses considered to be nonliving organisms?

What characteristic of viruses distinguishes them from cells?

Which statement best describes fungi?

The human immunodeficiency virus (HIV) causes AIDS. The first known human cases AIDS were in Africa in the late 1950s. Since then, tens of millions of people have died from the disease, and tens of millions more people all over the world are infected. Which term BEST describes the disease AIDS?

Millions of people living all over the world have cancer. Is cancer a pandemic?

The bacteria B. anthracis causes the deadly disease anthrax. Here is one way humans can contract the disease:

1.The bacteria form tough endospores that rest in soil indefinitely.

2.Grazing animals such as sheep inhale the endospores from the soil.

3.Once inside the sheep, the spores reactivate and cause infection.

4.Infected sheep then pass the bacteria to humans who become infected.

In this scenario, what is the vector of anthrax?

Dhumans

The table below shows some human diseases, how they are spread, and the state of the carrier that infects humans with the virus.

Which tool is MOST responsible for preventing future pandemics of smallpox?

Which is a career that would use microorganisms to remove pollutants from water?

What is one benefit of giving farm animals vaccines?

To help meet the world’s demand for food, which biotechnological process is most likely to be used by agricultural industries?

Which is an example of scientists using biotechnology to benefit aquaculture?

Which organisms are used to manufacture human insulin?