Biology Midterm Exam Questions and Answers, Exams of Nursing

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Biology Midterm Exam Questions and

Answers

Vision

1. What are three important components of a hyper column in primary visual cortex? Ocular dominance columns Orientation selective columns blobs
2. Draw a diagram that explains how a complex cell in visual cortex can respond to a moving bar of light. Think about hierarchical organization.

3 simple cells:

Motion-sensitive complex cell

3. The figure above shows sites (black bars) at which that part of the visual pathway has been damaged. For the locations A, B and C, indicate which part of the visual field (nasal, temporal, both or neither) of both the left and right eye is affected by the damage. Use shading to indicate which parts of the visual field is blinded.

objects are on a table behind a screen, and the patient cannot see them. Can he reach around the screen and identify and pick up the baseball with his left hand? Explain your answer. Yes. The image of the baseball reached his right visual cortex, but the information could not be transmitted to language areas in the left hemisphere because the corpus callosum was sectioned. However, the language areas in his right hemisphere recognized the image even though it could not be expressed verbally. This information was transmitted to the motor cortex in the right hemisphere which controls the left hand. Since the corticospinal tract is intact, the patient was able to identify the baseball by touch and pick it up with his left hand.

Learning and memory questions

1. The graphs above show the relative size of the Aplasia gill withdrawal reflex across repeated trials of identical touch stimulation of the siphon. What is the term for the progressive reduction in size from trial 1 to 4, and what might explain this? Habituation, depletion of synaptic vesicles in the presynaptic terminal of the siphon sensory neuron
2. Long-term sensitization of the gill withdrawal reflex requires that the conditioned stimulus (siphon stimulation) and the unconditioned stimulus (tail shock) be (circle correct answer) Paired or unpaired.
3. Fill-in-the-blank. Long-term sensitization in Aplasia involves activation of CREB to initiate gene transcription of ubiquitin which activates a persistent increase in the catalytic subunit of PKA, which in turn phosphorylates K+ channels to make them less likely to open, thereby depolarizing the presynaptic terminal. In addition, there is growth of additional synaptic terminals of the sensory neuron onto the Moto neuron.
   4. Describe one persistent change in the synapse between the siphon sensory neuron to the gill Moto neuron that accounts for this. (1) Growth of additional presynaptic terminals from the siphon sensory neuron to the gill Moto neuron

7. Which types of learning/memory processes did HM have completely intact? (Circle or mark the correct answers). a.long-term memory b.semantic memory c.mirror tracing d.immediate memory e.declarative memory f. short-term memory g.conditioning h.priming i. working memory j. non-declarative memory k.episodic memory
8. What 3 additional synaptic events occur during late-LTP? (1) Increase synapse size, (2) increase in synapse number, (3) activate previously inactive synapses
9. In order to make these synaptic changes persistent, evidence would suggest that cells use both plasticity related proteins (PRPs) and synaptic tagging molecules to signal which spines should be modified for a longer period of time. (Answer true/false below) T This is known as Synaptic Tagging and Capture. T This theory suggests these tagging molecules are present during both early and late LTP. T If no PRPs are present, the spine eventually returns to its basal state.
10. After late-LTP has occurred, a memory has been encoded and consolidated. This is part of the process of converting amemory to memory. Short-term; long-term

Motor questions A B

1. In the figure above, draw the connections from the muscle spindle (in A) and Golgi tendon organ (B), both indicated by blue, to the spinal cord. For A, assume that the flexor muscle has been passively stretched. For B, assume that the flexor muscle is contracting. Draw Moto neurons in the spinal cord and indicate their connections to flexor and extensor muscles in the respective arms. Draw in the connections from the afferent fibers (muscle spindle in A, Golgi tendon organ in B) to the Moto neurons. Draw in interneurons if necessary. Indicate if the interneuron is excitatory (open circle) or inhibitory (filled circle). Be sure to include connections for reciprocal inhibition in A. In B, show connections that explain what happens to the extensor muscle when the flexor contracts.

2a. what are two things that the yellow shaded areas in the raster displays indicate?

1. Motor cortex neuron increases its firing when the arm movement is in that particular direction.
2. The neuron starts firing before the movement begins. 2b. what does the answer to 2a mean? That the neuron increases its firing just prior to the onset of movements that are generally toward the left and upward.