What characteristic do ALL cells have in common?

Which cellular process takes place in the ribosomes that are bound to the endoplasmic reticulum?

Which of the following kingdoms include prokaryotic organisms?

Which sequence shows the increasing complexity of levels of organization in multicellular organisms?

Meiosis produces 4 genetically different haploid cells. Mitosis produces

Which of these statements best explains the process of energy conversion that takes place in the mitochondria?

Proteins and polysaccharides are polymers. These polymers are formed by dehydration synthesis. Which statement correctly identifies a difference in the structure of proteins and polysaccharides?

Both euglena and cyanobacteria are photosynthetic unicellular organisms found in pond water. The feature that distinguishes euglena from cyanobacteria is the -

Which cellular process takes place in the ribosomes that are bound to the endoplasmic reticulum?

Which of these must occur during S phase of the cell cycle so that two daughter cells can be produced during M phase?

Cold sores are caused by the herpes simplex virus type 1. A company that wants to develop antiviral drugs would ask a research immunologist to study-

Cell differentiation is critical during embryonic development. The process of cell differentiation results in the production of many types of cells, including germ, somatic, and stem cells. Cell differentiation is most directly regulated by-

Carbohydrates are more easily metabolized than lipids. However, on a gram-for-gram basis lipids provide cells with more-

A person infected with the human immunodeficiency virus (HIV) may not have any symptoms for a period of time. During this period the virus affects the body by doing which of the following?

Which group of organelles is directly responsible for the production of new molecules within a cell?

Severe acute respiratory syndrome (SARS) is an illness caused by a coronavirus. Symptoms including a high fever, headaches, and body aches typically occur two to seven days after infection by the virus. SARS is more serious in elderly patients. This information suggests that the reproductive cycle of the SARS virus is-

The cellular process known as the sodium-potassium pump was discovered in the 1950s by Jens Christian Skou, a Danish scientist. This process is a form of active transport that moves three sodium ions to the outside of a cell for every two potassium ions that it moves into the cell. Which of these best explains why energy is needed for active transport?

Which of the following biomolecules typically contains both nitrogen and phosphate?

Telophase is a stage of a cellular process that begins after the chromosomes have moved to opposite poles of the cell. During which cellular process does telophase occur?

Most plants have hair-like cells called trichomes that project from the surface and help the plants in many ways. In some plants trichomes secrete toxic substances that most likely perform which function?

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 —

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?

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 —

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 —

The 1918 influenza epidemic killed between 50 million and 100 million people worldwide. This epidemic happened near the end of World War I. More people died from the influenza epidemic than were killed in the war. Which of the following explains why this virus was so deadly worldwide?

Four different nucleotides are used as building blocks of DNA. Which of the following can be used to distinguish one nucleotide from another?

In the early 1900s a scientist hypothesized a link between DNA and the production of proteins in the cytoplasm. However, the fact that DNA could not be found outside the nucleus led scientists to believe that another substance was also involved in the synthesis of protein in the cytoplasm. In the 1940s scientists performed an experiment that ultimately identified the site of protein synthesis. They also identified the molecule responsible for transporting information from the nucleus to the site of protein synthesis. What was this newly identified molecule?

As a fertilized egg divides, the cells differentiate because they —

Cells pass through a G2 checkpoint before entering mitosis. Ideally, if DNA damage is detected, the cells do not enter mitosis until the damage is repaired. Why is DNA damage repaired before cells enter mitosis?

Oncogenes are mutated forms of genes. Oncogenes can transform a cell into a tumor cell. Some tumor cells are benign, while others are malignant. How does the presence of an oncogene lead to the formation of a tumor?