Answer the following question given this paragraph: 2. The second step in eukaryotic cell division is division of the cell's nucleus. This includes division of the chromosomes. This step is called mitosis. It is a complex process that occurs in four phases. The phases of mitosis are described below. Q: The second step in eukaryotic cell division is division of which part of the cell? Choices: - protons - molecules - Cell Division - nucleus A:
nucleus
Answer the following question given this paragraph: The structure of the different types of blood vessels reflects their function or layers. There are three distinct layers, or tunics, that form the walls of blood vessels (Figure 40.16). The first tunic is a smooth, inner lining of endothelial cells that are in contact with the red blood cells. The endothelial tunic is continuous with the endocardium of the heart. In capillaries, this single layer of cells is the location of diffusion of oxygen and carbon dioxide between the endothelial cells and red blood cells, as well as the exchange site via endocytosis and exocytosis. The movement of materials at the site of capillaries is regulated by vasoconstriction, narrowing of the blood vessels, and vasodilation, widening of the blood vessels; this is important in the overall regulation of blood pressure. Veins and arteries both have two further tunics that surround the endothelium: the middle tunic is composed of smooth muscle and the outermost layer is connective tissue (collagen and elastic fibers). The elastic connective tissue stretches and supports the blood vessels, and the smooth muscle layer helps regulate blood flow by altering vascular resistance through vasoconstriction and vasodilation. The arteries have thicker smooth muscle and connective tissue than the veins to accommodate the higher pressure and speed of freshly pumped blood. The veins are thinner walled as the pressure and rate of flow are much lower. In addition, veins are structurally different than arteries in that veins have valves to prevent the backflow of blood. Because veins have to work against gravity to get blood back to the heart, contraction of skeletal muscle assists with the flow of blood back to the heart. Q: Three distinct layers or tunics form the walls of what structures; the first is a smooth, inner lining of endothelial cells in contact with the red blood cells? Choices: - lungs - white blood cells - alveoli - blood vessels A:
blood vessels
Q: Answer the following question given this paragraph: Figure 12.25 Graded Potentials Graded potentials are temporary changes in the membrane voltage, the characteristics of which depend on the size of the stimulus. Some types of stimuli cause depolarization of the membrane, whereas others cause hyperpolarization. It depends on the specific ion channels that are activated in the cell membrane. Q: Graded potentials are temporary changes in what, the characteristics of which depend on the size of the stimuli? Choices: - components voltage - organic voltage - organism voltage - membrane voltage A:
A: membrane voltage
Question: Answer the following question given this paragraph: Cellular respiration occurs in the mitochondria. Figure 20.13 "Respiration" shows the mitochondrion's two membranes: outer andinner. The inner membrane is extensively folded into a series of internal ridges calledcristae. Thus there are two compartments in mitochondria: the intermembrane space, which lies between the membranes, and the matrix, which lies inside the inner membrane. Q: What part of the cell does cellular respiration occur? Choices: - glucose - proton - nuclei - mitochondria A:
Answer: mitochondria
*Question*
Answer the following question given this paragraph: Q: How long does it take for the earth to make a complete rotation of its axis? Choices: - one year - one month - 24.25 hours - 24 hours A:
**Answer**
24 hours
Answer the following question given this paragraph: Chadwick's work resulted in a new understanding of the nucleus of the atom; it is comprised of both protons and neutrons. Because the masses of subatomic particles are so small, a new unit, called an atomic mass unit (amu), was defined. Protons and neutrons each have a mass of approximately one amu. The Table below describes the characteristics of the three subatomic particles we have discussed. Q: Because the masses of subatomic particles are so small, a new unit, called what, was defined? Choices: - atomic volume unit - particle mass unit - nuclear mass unit - atomic mass unit A:
atomic mass unit