A segment of DNA produces methionine, threonine, histidine, aspartate, and glycine when translated. A substitution mutation occurs and causes the synthesis of the segment as shown. Which is the new peptide chain when the new DNA segment is translated?

Frogs and toads belong to the order Anura. The smallest organism in this order is about 7 millimeters long, while the largest is about 30 centimeters long. Which of these lists best describes this order?

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?

On March 24, 1989, an oil tanker ran aground on Bligh Reef in Prince William Sound, Alaska, and spilled millions of liters of crude oil. The graph shows pink salmon populations in Prince William Sound from 1970 to 1999. What do these data suggest about the effect the oil spill had on pink salmon?

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?

A student wants to use the Venn diagram to show the characteristics of two kingdoms of organisms. The characteristics that the two kingdoms share will be listed in the shaded area where the circles intersect. Which of these is a characteristic that the student should list in the shaded part of the diagram?

Part of an important cellular process involving a DNA strand is modeled. What is the purpose of this cellular process?

A student preparing for a hike wants to pack a snack that has biomolecules that provide quickly available energy but few excess calories. Which nutrition label lists the best combination of biomolecules that provide quickly available energy while providing the fewest calories from other types of biomolecules?

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 levels of nucleotide sequences. Nucleotide sequence comparisons are possible because all organisms share which of the following?

An informational pamphlet in a health clinic describes an interaction between body systems. Which statement identifies the body systems that are directly involved in the interaction described and explains how they accomplish the interaction?

Models of the human immunodeficiency virus (HIV) and an animal cell are shown. What is the difference in function of the glycoprotein structures of an HIV virion and the cilia of an animal cell?

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 researchers to compare the genomes of people who do not have a particular condition with the genomes of people who do have this 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?

The mimosa plant displays thigmotropism by collapsing its leaves in response to touch, as shown in the pictures below. The plant on the left is undisturbed. The upper stem of the plant on the right has been touched. What is the most likely benefit of this mechanism for the plant?

The model represents the change in DNA content of a cell during the cell cycle. Which part of the model represents the S phase?

Coradas 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?