Answer the following question given this paragraph: 12.4 The Action Potential The nervous system is characterized by electrical signals that are sent from one area to another. Whether those areas are close or very far apart, the signal must travel along an axon. The basis of the electrical signal is the controlled distribution of ions across the membrane. Transmembrane ion channels regulate when ions can move in or out of the cell, so that a precise signal is generated. This signal is the action potential which has a very characteristic shape based on voltage changes across the membrane in a given time period. The membrane is normally at rest with established Na+ and K+ concentrations on either side. A stimulus will start the depolarization of the membrane, and voltage-gated channels will result in further depolarization followed by repolarization of the membrane. A slight overshoot of hyperpolarization marks the end of the action potential. While an action potential is in progress, another cannot be generated under the same conditions. While the voltage-gated Na+ channel is inactivated, absolutely no action potentials can be generated. Once that channel has returned to its resting state, a new action potential is possible, but it must be started by a relatively stronger stimulus to overcome the K + leaving the cell. The action potential travels down the axon as voltage-gated ion channels are opened by the spreading depolarization. In unmyelinated axons, this happens in a continuous fashion because there are voltage-gated channels throughout the membrane. In myelinated axons, propagation is described as saltatory because voltage-gated channels are only found at the nodes of Ranvier and the electrical events seem to "jump" from one node to the next. Saltatory conduction is faster than continuous conduction, meaning that myelinated axons propagate their signals faster. The diameter of the axon also makes a difference as ions diffusing within the cell have less resistance in a wider space. Q: The nervous system is characterized by electrical signals that are sent from one area to another. whether those areas are close or very far apart, the signal must travel along this? Choices: - axial - hairs - tendons - axon A:
axon
(Question)
Answer the following question given this paragraph: Figure 16.33 The wave on a guitar string is transverse. The sound wave rattles a sheet of paper in a direction that shows the sound wave is longitudinal. Q: The wave on a guitar string is transverse. the sound wave rattles a sheet of paper in a direction that shows the sound wave is what? Choices: - obtuse - lateral - magnetic - longitudinal A:
(Answer)
longitudinal
Ques: Answer the following question given this paragraph: Stuart Chalmers. Cows digest cellulose with the aid of methanogens . CC BY 2.0. Q: Which of the animals digest cellulose with the aid of methanogens? Choices: - pigs - apes - goats - cows A:
Ans: cows
(Q).
Answer the following question given this paragraph: How do lungs allow air in? Air moves into and out of the lungs by the movement of muscles. The most important muscle in the process of breathing is the diaphragm , a sheet of muscle that spreads across the bottom of the rib cage. The diaphragm and rib muscles contract and relax to move air into and out of the lungs. During inhalation, the diaphragm contracts and moves downward. The rib muscles contract and cause the ribs to move outward. This causes the chest volume to increase. Because the chest volume is larger, the air pressure inside the lungs is lower than the air pressure outside. This difference in air pressures causes air to be sucked into the lungs. When the diaphragm and rib muscles relax, air is pushed out of the lungs. Exhalation is similar to letting the air out of a balloon. Q: What is the most important muscle involved in the process of breathing? Choices: - mouth - chest - trachea - diaphragm A:
(A).
diaphragm
Ques:Answer the following question given this paragraph: If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. Q: In human beings, when a female becomes pregnant, what is fertilized and then embedded in the uterus? Choices: - dna - follicle - sperm - egg A:

Ans:egg
Answer the following question given this paragraph: Respiration is the process in which gases are exchanged between the body and the outside air. The lungs and other organs of the respiratory system bring oxygen into the body and release carbon dioxide into the atmosphere. Q: What is the process in which gases are exchanged between the body and the outside air? Choices: - ingestion - metabolism - precipitation - respiration A:
respiration