Question

question 4
based on the previous scenario when dan encounters the bear, which neurotransmitter is most likely to engage his fight or flight response?
○ gaba
○ substance p
○ norepinephrine
○ serotonin

question 5
1 pts
dr. johnson is conducting a study to understand the factors contributing to addiction behavior. she gathers a group of individuals with a family history of addiction and another group with no such history. she then exposes both groups to the same environmental tensions and access to addictive substances, monitoring their responses and behaviors over time. based on this scenario, what is dr. johnson primarily investigating?
○ the interplay between genetic predisposition and environmental influences on addiction behavior
○ the influence of environmental factors on addiction behavior
○ the role of genetics in determining addiction behavior
○ the effectiveness of different treatments for addiction

question 6
1 pts
during a neurophysiology lab, students are investigating how neurons generate action potentials. they apply increasing levels of electrical stimulation to a neuron and measure its response. they observe that below a certain threshold, no action potential is generated. however, once the threshold is reached, a full action potential is triggered, regardless of whether the stimulus intensity is just above the threshold or significantly higher. which principle of neural function does this observation illustrate?
○ the all-or-none response principle
○ a lack of modulation across the axon
○ the sensory coding principle
○ the graded potential principle

Explanation:

Question 4

To determine the neurotransmitter for fight - or - flight, we recall that norepinephrine (and epinephrine) are key in the sympathetic nervous system's fight - or - flight response. Among the options, norepinephrine is the one associated with this response. (Note: Assuming "norepinephrine" is one of the options, likely the correct one. If the option is "Norepinephrine" (maybe misspelled in the image), that's the answer. If the options were, for example, with norepinephrine as an option, it's the right choice as it's involved in activating the fight - or - flight response by increasing heart rate, blood pressure, etc.)

Dr. Johnson has two groups: one with a family history of addiction (genetic predisposition) and one without. She exposes both to the same environmental stressors and addictive substances. So she is looking at how genetic predisposition (family history) and environmental influences (same stressors and substance access) interact to affect addiction behavior. The first option says "The interplay between genetic predisposition and environmental influences on addiction behavior", which matches. The second option only focuses on environmental factors, the third only on genetics, and the fourth on treatments (not what's being done here).

The all - or - none response principle states that a neuron either fires an action potential (if the stimulus reaches the threshold) or does not fire at all. Once the threshold is reached, the action potential is always the same magnitude, regardless of stimulus intensity above the threshold. The students observed that below the threshold, no action potential; above, a full action potential regardless of stimulus intensity. This matches the all - or - none response principle. The other options: "A lack of modulation around the axon" is not related, "The membrane potential principle" is too vague, and "The graded potential principle" is about potentials that vary in magnitude (opposite of what's seen here as action potential is all - or - none).

Answer:

(Assuming the correct option is the one with norepinephrine, e.g., if the option is "Norepinephrine" (or the correctly spelled version in the options), then the answer is that option. Since the image's option for norepinephrine might be there, we'll go with the option representing norepinephrine. If the options are as given with "norepinephrine" (or similar), that's the answer.)

Question 5