BIOL 212 Exam 4 Review SI Session 12/2/13
ANSWER KEY
Ch. 38: Plant Transport (Sections 1, 2, 4)
1. In order for minerals and nutrients to move into the roots from the soil they must:
a. Travel with their concentration gradients
b. Travel against their concentration gradients – therefore active transport is required
c. Undergo passive diffusion
d. Undergo facilitated diffusion
2. The minerals dissolved in water that get taken up by the roots (as in the question above) travel to the shoots via:
a. Xylem
b. Phloem
c. The cohesion-tension theory
d. Both a & b
e. Both a & c
f. Both b & c
Ch. 48: Respiratory Systems (Sections 1, 3, 5-7)
3. Oxygen saturation of hemoglobin is:
a. Higher in body tissue capillaries and lower in the lung capillaries
b. Lower in body tissue capillaries and higher in the lung capillaries
c. High in both the body tissue and lung capillaries
d. Low in both the body tissue and lung capillaries
4. What effect will an increase in temperature have on a human oxygen-hemoglobin dissociation curve?
a. It will shift it to the left
b. It will shift it to the right – when cells are metabolically active they produce heat, metabolically active cells require more oxygen, which means the Hb-O2 binding affinity needs to decrease. If the curve is shifted right, the % saturation of Hb with O2 is lower at the same partial pressure of oxygen compared to the original graph.
c. It will have no effect on the curve, only CO2 and H+ levels will shift the curve – high levels of CO2 and H+ also shift the curve to the right, but temperature does as well.
5. How is most of the oxygen we breathe in transported through our blood?
a. It binds to amino acids on Hemoglobin
b. It is dissolved in the plasma – some is, but not enough to meet requirements
c. It binds white blood cells
d. It binds to Fe molecules on Hemoglobin
Ch. 41: Cells of the Nervous System (Sections 1-4)
6. The brain causes your foot to kick by sending a signal down:
a. A sensory neuron
b. A motor neuron
c. An Interneuron
d. Need more information
7. In a neuron, if Na+ channels are unable to close and K+ channels are unable to open, what will happen to the membrane potential?
a. An action potential will not fire because the threshold potential will not be reached.
b. An action potential will fire but it will plateau at the top, it will not be able to depolarize.
c. The membrane will become even more negatively hyperpolarized.
d. The action potential will fire and will continue rising indefinitely.
8. Some neurotoxin keeps Ca2+ channels in a presynaptic cell from opening. This particular presynaptic cell contains vesicles of inhibitory neurotransmitters. What affect will this neurotransmitter have on the signal?
a. It will increase
b. It will decrease
Ch. 42: The Brain & Nervous Systems (Sections 2-4)
9. What might be a symptom of a dysfunctional amygdala?
a. Willingly entering clearly dangerous situations – by remembering the fear associated with it, the amygdala is involved in understanding/remembering emotions
b. The inability to perceive smell – olfactory bulbs
c. The inability to remember directions to a certain place – hippocampus
d. Inability to remember sequences of events – hippocampus
10. Why must genes be transcribed in order for one to create long term memories?
a. The genes encode second messengers that participate in intracellular pathways making neuronal communication easier and faster.
b. The genes encode enzymes that participate in neurodegeneration.
c. The genes encode proteins that make up whole new synapses.
d. Genes do not need to be transcribed to create long term memories.
11. Which is a possible way to treat Alzheimer’s Disease?
a. Inhibit β-secretase
b. Activate β-secretase – this enzyme is involved in Aβ clearance, which could be a possible treatment since Aβ accumulation in the cerebral cortex & hippocampus is associated with Alzheimer’s
c. Activate α-secretase
d. None of the above
Ch. 43: Sensory Systems (Sections 1, 2, 5)
12. What determines the pitch of a sound we hear?
a. The direction that the hair cell is bent
b. Whether the hair cell is a mechanoreceptor, chemoreceptor, nociceptors, etc.
c. The location on the cochlea of the hair cell being bent – and this is determined by the frequency of the sound waves reaching our ear
d. How far the hair cell is bent
13. What happens when the visual pigment retinal is in the trans conformation?
a. We perceive light – when it absorbs a photon it converts from cis- to trans-retinal which changes opsin so that is activates transducing which activates phosphodiesterase which converts cGMP to GMP, causing fewer cGMP available to bind & open Na+ channels, so Na+ channels close, the membrane hyperpolarizes (no action potentials) which stops the release of glutamate, the absence of glutamate is interpreted as absence of light Fig. 43.21, pg. 907
b. We perceive the absence of light (darkness)
c. We differentiate between different colors
14. What determines the strength of a stimulus as perceived by our brain?
a. The size of the action potentials
b. They type of receptor
c. How many action potentials are generated
d. The frequency of the action potentials
Ch. 44: Muscular-Skeletal Systems & Locomotion (Sections 2, 3, 6)
15. What would happen if Pi was unable to be released from the cross-bridge? The cross-bridge:
a. wouldn’t be able to complete the power stroke
b. wouldn’t be able to bind the actin (thin) filament
c. wouldn’t be able to reset for the next cycle
d. wouldn’t be able to detach from the actin filament
16. What role does Ca2+ play in the cross-bridge cycle?
a. It binds tropomyosin and moves it out of the way so that the myosin can bind actin
b. It binds tropomyosin which moves troponin out of the way so myosin can bind actin
c. It binds troponin which moves tropomyosin out of the way so myosin can bind actin
d. It binds actin & induces a conformational change so that myosin can bind
17. What type of neurotransmitter is acetylcholine (ACh)?
a. Excitatory – present at neuromuscular junctions, binds ACh receptor which is a ligand-gated ion channel, lets Na+ ions into muscle cell, inducing action potentials which release Ca2+ which triggers contraction
b. Inhibitory
18. T/F Action potentials are only present in neuronal cells
a. One example: muscle cells, the propagation of action potentials leads to release of Ca2+ and thus contraction