Ques: Q: What carry messages from our sensory organs and others to the central nervous system? Read this paragraph and choose the correct option from the provided answers: 20.7 Nerve ConductionElectrocardiograms Nerve Conduction Electric currents in the vastly complex system of billions of nerves in our body allow us to sense the world, control parts of our body, and think. These are representative of the three major functions of nerves. First, nerves carry messages from our sensory organs and others to the central nervous system, consisting of the brain and spinal cord. Second, nerves carry messages from the central nervous system to muscles and other organs. Third, nerves transmit and process signals within the central nervous system. The sheer number of nerve cells and the incredibly greater number of connections between them makes this system the subtle wonder that it is. Nerve conduction is a general term for electrical signals carried by nerve cells. It is one aspect of bioelectricity, or electrical effects in and created by biological systems. Nerve cells, properly called neurons, look different from other cellsthey have tendrils, some of them many centimeters long, connecting them with other cells. (See Figure 20.27. ) Signals arrive at the cell body across synapses or through dendrites, stimulating the neuron to generate its own signal, sent along its long axon to other nerve or muscle cells. Signals may arrive from many other locations and be transmitted to yet others, conditioning the synapses by use, giving the system its complexity and its ability to learn. Choices: - fibers - valves - blood vessels - nerves A:
Ans: nerves

Ques: Q: What substances digest the food in the vacuole of an ingestive protist? Read this paragraph and choose the correct option from the provided answers: Ingestive protists ingest, or engulf, bacteria and other small particles. They extend their cell wall and cell membrane around the food item, forming a food vacuole. Then enzymes digest the food in the vacuole. Choices: - carbohydrates - lipids - hormones - enzymes A:
Ans: enzymes

Ques: Q: The major component of a solution is called what? Read this paragraph and choose the correct option from the provided answers: The major component of a solution is called the solvent. The minor component of a solution is called the solute. By major and minor we mean whichever component has the greater presence by mass or by moles. Sometimes this becomes confusing, especially with substances with very different molar masses. However, here we will confine the discussion to solutions for which the major component and the minor component are obvious. Solutions exist for every possible phase of the solute and the solvent. Salt water, for example, is a solution of solid NaCl in liquid water; soda water is a solution of gaseous CO2 in liquid water, while air is a solution of a gaseous solute (O2) in a gaseous solvent (N2). In all cases, however, the overall phase of the solution is the same phase as the solvent. Choices: - solute - mixture - water - solvent A:
Ans: solvent

Ques: Q: What occurs when substances move from areas of lower to higher concentration or when very large molecules are transported? Read this paragraph and choose the correct option from the provided answers: Active transport requires energy from the cell. It occurs when substances move from areas of lower to higher concentration or when very large molecules are transported. Types of active transport include ion pumps, such as the sodium-potassium pump, and vesicle transport, which includes endocytosis and exocytosis. Choices: - migration - diffusion - passive transport - active transport A:
Ans:
active transport