Parrotfish are herbivores that are found in coral reefs. To escape predation, a parrotfish will graze with a rabbitfish, which has venomous spines at the end of its pelvic fins. The rabbitfish does not benefit from this relationship. Which type of relationship do the parrotfish and the rabbitfish have in the coral-reef environment?

As ecosystems move through the stages of succession, the populations of organisms in them change. Which of the following describes the stage of succession likely to have the most species diversity?

Cells typically respond to DNA damage in three ways: by ceasing to grow and divide until the damage is repaired, by permanently ceasing to grow and divide, or by dying. In 2010 a group of scientists reported that a certain kind of immune reaction can cause DNA damage that leads to a fourth response. DNA damage can turn off genes involved in cell-signaling pathways. Turning off these genes can cause less-mature cells to divide too rapidly, often leading to the development of __

In recent years humans have interfered with the natural balance within deer populations in various ecosystems. The interference includes eliminating predators of the deer. Which of the following statements correctly describes the long-term outcome of this interference?

Organisms can be classified based on homology, which is shared characteristics inherited from a common ancestor. In the past, homologies were based on studies of anatomical structures and patterns of embryonic development. In more recent years, the use of molecular biology techniques has allowed homologies to be compared at the level of nucleotide sequences. Nucleotide sequence comparisons are possible because all organisms share which of the following?

Diatoms are one of the most common types of phytoplankton in marine habitats. Like plants, diatoms contain chlorophyll and produce glucose from which of the following?

A genome-wide association study involves searching the genomes of many people in order to find genetic variations associated with common diseases such as cancer, asthma, and diabetes. These studies are possible because of computer databases that allow researches to compare the genomes of people who do not have a particular condition with the genomes of people who have the condition. In order to do this type of testing, researchers need blood samples or cheek swabs from people. Obtaining these samples is necessary because blood and cheek cells contain __

When the level of carbon dioxide in the blood is too high, the excess carbon dioxide reacts with water and produces carbonic acid. The carbonic acid causes the blood pH to become more acidic. When the blood pH becomes too acidic, chemoreceptors in the brain instruct the body to react and maintain homeostasis in blood pH. Which of these responses by the body would eliminate the excess carbon dioxide and help maintain homeostasis in blood pH?

Two populations of mice living in the same forest are separated by a large water-filled ditch. After a rainstorm, flooding brings several mice from one population to the other population. When the mice from the first population reproduce with members of the second population, which of the following will likely occur?

Coracias garrulus is a blue bird with an orange-brown back. The offspring of this bird have an effective defense mechanism. The young birds vomit and cover themselves in a foul-smelling orange liquid when they sense a threat by predators. Which two systems alert the young bird to the danger and help produce the vomit it uses as a defense?

Cells can generate as many as 36 to 38 molecules of adenosine triphosphate (ATP) from the metabolism of one molecule of glucose. Which cellular process results in this amount of ATP production?

Fireflies emit light. The production of light by an organism is called bioluminescence. To generate visible light, cells in a firefly’s tail produce thousands of luciferase enzymes. Luciferase binds to a chemical called luciferin. Once bound, the luciferase enzyme speeds up a chemical reaction that combines an oxygen molecule and luciferin to produce oxyluciferin. This reaction requires energy and releases light. Which of the following best describes how the luciferase enzyme speeds up the chemical reaction?

Facial dimples and free earlobes are both considered dominant human traits. What are the expected phenotypes of the offspring of a female with dimples and free earlobes (DDFf) and a male with no dimples and attached earlobes (ddff)?

At birth Himalayan rabbits are usually white over their entire bodies. But when parts of their bodies reach temperatures below 35°C, a pigment that causes these parts to turn black is produced. Which of the following is most likely the cause of this phenomenon?

The differences between two molecules include the type of sugar that forms a section of the molecules and the identity of one of the four nitrogenous bases that make up another section of the molecules. These two molecules are —

A science class is planning a field trip to a local farm that has a large pond. Which of the following lists the order of biological organization from smallest to largest that the students can expect to find at the pond?

A student is asked to draw a food web in which the same organism is a primary consumer as well as a secondary consumer. How should the organism be represented in the food web?

Bats eat insects that damage crops and mosquitoes that are vectors for disease. One million bats can eat several tons of insects per night, saving billions of dollars in pesticides yearly. Agricultural and public health scientists are concerned about the spread of white-nose syndrome (WNS). WNS is a result of a fungus that can infect cave-dwelling bats. While bats hibernate during winter months, the fungus covers the bats’ face and wings. WNS has a near 100% mortality rate, and 5.7 million bats have died since the discovery of the fungus in 2006. Many scientists are searching for ways to protect these bats. The relationship between this fungus and bats can best be defined as —

Human body cells each have 46 chromosomes in their nuclei. Meiosis is necessary in order to ensure that each gamete produced in the human body has —

How do an increase in the organic matter in soil and an increase in soil depth affect the population of plants in an area?

In dry desert areas poor drainage can lead to a buildup of salt in water supplies. A student performed an investigation to study the effects of salinity on the germination rates of seeds. The student placed seeds in several solutions containing 0% to 3% salt. The length of the radicle, which is the root of the germinating seed, ranged from 49 mm in the 0% salt solution to 0 mm in the 3% salt solution. The data from this investigation suggest that increased salinity in more areas may lead to a decrease in which of the following?

In the 1960s the molecular biologist George Streisinger developed the strand-slippage hypothesis. Streisinger noticed that mutations occurred in areas of DNA that contained many repeated sequences. When a strand-slippage error occurs, an insertion mutation can result. How does the insertion mutation affect the DNA?

Normal fruit flies have brownish-yellow bodies, and this body color is dominant. A mutation in the gene for body color can produce flies with an ebony body color. A homozygous normal fruit fly (e+e+) is crossed with a homozygous ebony fruit fly (ee). What is the predicted outcome of this genetic cross?

Scientists can bioengineer skin in a laboratory to treat severe burns and other types of skin injuries. This bioengineered tissue is grown from living cells. The cellular process that enables the cells to grow and develop into tissue is —