There is a ________ difference between a pH of 5 and a pH of 6.

A) 10x
B) 2x
C) 5x
D) 100x
E) 50x

Which of the following events occurs in both the G₁ and the G₂ phases?

A) Mitosis
B) DNA replication
C) Cytokinesis
D) Spindle apparatus formation
E) Cell growth

Which group of algae are thought to be the most closely related to land plants?

A) brown
B) red
C) green
D) dinoflagellates
E) diatoms

The hemoglobin protein, responsible for carrying oxygen in red blood cells, is composed of four polypeptide chains: two alpha-globin and two beta-globin. Sickle cell anemia is characterized by a mutation that causes a change in one amino acid in the beta-chain. This change substitutes a hydrophobic amino acid side chain for the normal polar side chain; therefore, these mutant chains stick to other hemoglobin molecules instead of being attracted to water molecules in the cellular environment. As a result, many hemoglobin molecules clump together, forming large fibers and sickle-shaped red blood cells that are unable to deliver needed oxygen to the body's tissues. The sickle cell mutation affects which level(s) of hemoglobin structure?

A) tertiary and quaternary only
B) primary and secondary only
C) primary plus abnormal protein aggregation
D) secondary plus abnormal protein aggregation
E) tertiary only

You conduct an experiment in which you inactivate Ras proteins in fibroblast cells. Which of the following is the most immediate consequence of this procedure?

A) The fibroblasts divide uncontrollably.
B) The fibroblasts synthesize excess DAG.
C) The fibroblasts synthesize excess G protein.
D) The fibroblasts no longer respond to calmodulin.
E) The fibroblasts no longer synthesize DNA in response to growth factors.

Labor-management partnerships have been shown to be effective in creating better labor-management relations, reducing workplace disputes, and improving performance.

If you change your hands from a position where they are pressed together to where they are cupped to collect a handful of water, you have mainly rotated which arm bone(s) ?

A) humerus
B) scapula
C) ulna
D) radius
E) carpels

The hepatic portal vein is formed by the union of the splenic vein and the ________.

A) superior mesenteric vein
B) inferior mesenteric vein
C) hepatic vein
D) renal vein
E) gastric vein