Q: Answer the following question given this paragraph: Rising air currents carry water vapor into the atmosphere. As the water vapor rises in the atmosphere, it cools and condenses. Condensation is the process in which water vapor changes to tiny droplets of liquid water. The water droplets may form clouds. If the droplets get big enough, they fall as precipitation. Q: Clouds are formed from what? Choices: - ice crystals - snow flakes - dust particles - water droplets A:
A: water droplets

Q: Answer the following question given this paragraph: 3.4 | The Cell Membrane By the end of this section, you will be able to: Understand the fluid mosaic model of membranes Describe the functions of phospholipids, proteins, and carbohydrates in membranes A cell's plasma membrane defines the boundary of the cell and determines the nature of its contact with the environment. Cells exclude some substances, take in others, and excrete still others, all in controlled quantities. Plasma membranes enclose the borders of cells, but rather than being a static bag, they are dynamic and constantly in flux. The plasma membrane must be sufficiently flexible to allow certain cells, such as red blood cells and white blood cells, to change shape as they pass through narrow capillaries. These are the more obvious functions of a plasma membrane. In addition, the surface of the plasma membrane carries markers that allow cells to recognize one another, which is vital as tissues and organs form during early development, and which later plays a role in the "self" versus "non-self" distinction of the immune response. The plasma membrane also carries receptors, which are attachment sites for specific substances that interact with the cell. Each receptor is structured to bind with a specific substance. For example, surface receptors of the membrane create changes in the interior, such as changes in enzymes of metabolic pathways. These metabolic pathways might be vital for providing the cell with energy, making specific substances for the cell, or breaking down cellular waste or toxins for disposal. Receptors on the plasma membrane's exterior surface interact with hormones or neurotransmitters, and allow their messages to be transmitted into the cell. Some recognition sites are used by viruses as attachment points. Although they are highly specific, pathogens like viruses may evolve to exploit receptors to gain entry to a cell by mimicking the specific substance that the receptor is meant to bind. This specificity helps to explain why human immunodeficiency virus (HIV) or any of the... Q: What encloses the border of animal cells? Choices: - Jacket membrane - dust membrane - cells membrane - plasma membrane A:
A: plasma membrane

Q: Answer the following question given this paragraph: Consider a gigantic tub filled with water as shown below. A column of water with a cross-sectional area of 1.00 m 2 is designated. If we multiply the cross-sectional area by the height of the column, we get the volume of water in this column. We can then multiply this volume by the density of water, 1000. kg/m 3 , and get the mass of water in the column. We then multiply this mass by the acceleration due to gravity, , to get the weight of the water in this column. Q: What do you get by multiplying volume by the density of water? Choices: - velocity of water - temperature of water - weight of water - mass of water A:
A: mass of water

Q: Answer the following question given this paragraph: Dipole-dipole forces are the attractive forces that occur between polar molecules. A molecule of hydrogen chloride has a partially positive hydrogen atom and a partially negative chlorine atom. In a collection of many hydrogen chloride molecules, they will align themselves so that the oppositely charged regions of neighboring molecules are near each other. Q: What are the attractive forces that occur between polar molecules called? Choices: - induced-dipole forces - particle - dipole forces - ion-dipole forces - dipole-dipole forces A:
A: dipole-dipole forces