Final Exam Bio Questions with correct Answers

Final Exam Bio117 2024|2024 Questions with correct Answers Which of the following statements is true about sensory neurons and motor neurons? -Sensory neurons take in information and send it to the CNS, whereas motor neurons receive information from the CNS and transmit it to muscle. -Sensory neurons send messages to the motor neurons. -Motor neurons send faster signals than sensory neurons. -Motor neurons receive information from the PNS. None of the answers are correct. Which neuron structure receives signals directly from other neurons? Which statement accurately describes the concentration of potassium ions in a resting neuron? -The concentration of potassium ions in the cell is low because open voltage-gated potassium ion channels are open. -The concentration of potassium ions is high because voltage-gated potassium ion channels are open. -The concentration of potassium ions is lower in the interior of the cell than in the extracellular medium. -The concentration of potassium ions is the same in the extracellular medium as in the cell interior -The concentration of potassium ions is greater in the interior of the cell than in the extracellular medium. Which of the following helps to maintain the normal resting potential of a neuron? (Select ALL that apply.) Voltage-gated chloride channels Sodium-potassium pumps Voltage-gated potassium channels Voltage-gated sodium channels Voltage-gated calcium channels Potassium leak channels Which of the following statements about action potentials is correct? -Action potentials for a given neuron vary in magnitude. -Movement of ions during the action potential occurs mostly through the sodium pump. -Action potentials for a given neuron vary in duration. -Action potentials are propagated down the length of the axon. True or False? For a given neuron, it is possible for one action potential to be smaller in magnitude or duration than the next. The three distinct phases of an action potential occur in what order? The membrane potential in a cell changes from -70 mV to -60 mV. What change has taken place within the cell? If the membrane potential of a neuron reaches its threshold potential, which event is most likely to occur next? Select the best answer to correctly complete the sentence: During the process of repolarization, ___ ions flood into the ____________. In a neuron at rest, which statement accurately describes the relative concentrations of ions? -Inside a neuron at rest, Na+ has a relatively high concentration, and K+ and Cl- have relatively low concentrations. -Inside a neuron at rest, Cl- has a relatively high concentration and Na+ and K+ have relatively low concentrations. -Inside a neuron at rest, Cl- and Na+ have relatively high concentrations and K+ has a relatively low concentration. -Inside a neuron at rest, K+ has a relatively high concentration, and Na+ and Cl- have relatively low concentrations. For a neuron at rest with a membrane potential of -65 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result in the ________. What happens at the peak of an action potential? What would be a consequence of a person having Na+ levels in the blood and interstitial fluids that are well below normal? Poison dart frogs can secrete a fluid from their skin that contains a potent neurotoxin. Look at the figure of an action potential of an axon that has been exposed to this neurotoxin. What is the most likely explanation for the effect? Why does the presence of a myelin sheath increase the speed at which a nerve impulse travels? The following steps refer to various stages in transmission at a chemical synapse.1. Neurotransmitter binds with receptors associated with the postsynaptic membrane.2. Calcium ions rush into the neuron's cytoplasm.3. An action potential depolarizes the membrane of the presynaptic axon terminal.4. The ligand-gated ion channels open.5. The synaptic vesicles release a supply of neurotransmitter into the synaptic cleft. Which sequence of events is correct? Which of the following is TRUE about summation. Excitatory Post-synaptic Potentials (EPSPs) Inhibitory Post-synaptic potentials (IPSPs) What binds to receptors on a postsynaptic neuron? How do neurotransmitters from a presynaptic neuron reach the synapse? Why did the squid axon become a model system for studying electrical signaling in animals? Which of the following are possible fates of neurotransmitters after they have been released from a presynaptic neuron and bind to a receptor on a postsynaptic neuron? (Select all that apply.) Neurotransmitters categorized as inhibitory are expected to _____. Phagocytic cells of innate immunity of vertebrates include ________. 1)neutrophils 2)macrophages 3)platelets 4) mast cells In vertebrates, what lines of defense are available against pathogens? Match the type of cells involved in the inflammatory response with their roles. You may use answers an many times as needed and you do not need to use all answers. 1) Release chemokines to recruit other cells to help 2) White blood cells that can phagocytize pathogens 3) Release histamines that cause constriction and dilation of blood vessels 4) Release cytokines that can induce fever Why is clonal selection (e.g. proliferation of certain cells) necessary for the adaptive immune response but not the innate immune response? -All cells in the innate immune response are abundant at birth and do not need to replicate. -It is important to increase the number of B cells of the adaptive immune response to mount a substantial response to a specific antigen. -Cells in the innate response do not require activation, and those in the adaptive responses do. -Clonal selection is used for targeting pathogens, and the innate response is only used to stop blood flow from a wound. A person unable to produce T cells, but still able to produce B cells, would be able to mount an immune response to which kind of pathogens? People infected with the human immunodeficiency virus (HIV) have few helper T cells. This is because HIV infects these cells and uses them as a place to replicate, destroying these helper T cells in the process. Given what you know about the role of helper T cells, which of the following is true of a person infected with HIV? What is responsible for activating T cells?