Chapter 8 The Chemical Senses

Chapter Eight The Chemical Senses

1. What are chemoreceptors? Choose the correct option.
A) Cells releasing hormones into the extracellular environment
B) Chemically sensitive cells that serve as sensory receptors
C) Chemically sensitive cells that mediate synapses at the neuromuscular junction
D) Special types of muscle cells sensitive to chemical changes in the extracellular
milieu


2. What changes occur in taste receptors when the membrane is depolarized during
receptor potential? Choose the correct option.
A) Voltage-gated Cachannels open, triggering the release of neurotransmitter.
B) Voltage-gated K channels open, triggering the release of neurotransmitter.
C) Voltage-gated Cachannels open, inhibiting the release of
neurotransmitter. D) Voltage-gated K channels open, inhibiting the release
of neurotransmitter.


3. Identify the causative agent for acidity and sourness. Choose the correct option.
A) HighpH
B) Na
C) Anions
D) Protons (H")


4. Identify the difference between sweet receptors and bitter receptors. Choose the
correct option.
A) G-protein-coupled receptors are present in bitter receptors.
B) Bitter receptors have only T2R, whereas sweet receptors have T1R2 and T1R3.
C) The second messenger pathway activation is
different. D) The transduction mechanisms are
different.


5. How does the brain distinguish between alternative tastes? Choose the correct
option.
A) Only by precisely labeled lines
B) Only by population coding
C) By frequency distribution
D) By roughly labeled lines and population coding


6. What is the function of odorant-binding proteins in the mucus? Choose the
correct option.
A) May concentrate odorants
B) May bind to viruses and bacteria
C) Generate new receptor cells
D) Produce the mucus

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