## TITLE('Chemosensation (Smell and Taste)')
## DESCRIPTION
## Select the statement that is TRUE or FALSE about chemosensation (smell and taste).
## ENDDESCRIPTION
## KEYWORDS('chemosensation (smell and taste)','true/false','multiple choice')
## DBsubject('Cell Biology')
## DBchapter('')
## DBsection('')
## Date('2026-07-12')
## Author('Neil R. Voss')
## Institution('Roosevelt University')

DOCUMENT();

loadMacros(
  "PGstandard.pl",
  "PGML.pl",
  "PGchoicemacros.pl",
  "parserRadioButtons.pl",
  "PGcourse.pl",
);

TEXT(beginproblem());
$showPartialCorrectAnswers = 1;

#==========================================================
# AUTO-GENERATED GROUPS FROM YAML
#==========================================================

@true_groups = (
  [
    'Many odorant receptors are GPCRs expressed in olfactory sensory neurons.',
    'Olfactory receptors are commonly seven-transmembrane GPCR proteins.',
  ],
  [
    'In olfaction, an odorant can activate a G protein that stimulates adenylyl cyclase.',
    'Odorant binding can lead to G<sub>olf</sub> activation and increased cAMP production.',
  ],
  [
    'cAMP can open cyclic nucleotide gated (CNG) ion channels in olfactory neurons.',
    'In olfaction, cAMP can act as a second messenger that gates ion channels.',
  ],
  [
    'Olfactory sensory neurons typically express one olfactory receptor gene.',
    'A single olfactory sensory neuron usually expresses one receptor type.',
  ],
  [
    'Odor identity is encoded by patterns of activity across many receptor types.',
    'Many odorants activate multiple receptors, producing a combinatorial code.',
  ],
  [
    'Salty taste commonly involves ion movement through channels rather than GPCR signaling.',
    'Salty taste is often detected by direct ion flow across the membrane.',
  ],
  [
    'Sour taste is linked to high acidity and elevated H<sub>3</sub>O<sup>+</sup> in foods.',
    'Sour tastants are associated with low pH and increased proton concentration.',
    'In sour sensing cells, protons (H+) can directly change ion channel activity.',
  ],
  [
    'Sweet taste commonly uses a GPCR pathway rather than a simple ion channel pore.',
    'Sweet taste is often detected by GPCR type receptors on taste cells.',
  ],
  [
    'Bitter taste commonly uses GPCR type receptors and downstream signaling.',
    'Many bitter compounds are detected through GPCR signaling in taste receptor cells.',
  ],
  [
    'Taste receptor cells can release neurotransmitter onto afferent neurons.',
    'Taste transduction ends with synaptic signaling to sensory neurons.',
  ],
  [
    'Signal amplification can occur when one activated receptor leads to many downstream second messengers.',
    'A signaling cascade can amplify a small input into a larger cellular response.',
  ],
  [
    'Phosphodiesterase can terminate cyclic nucleotide signals by breaking down cAMP or cGMP.',
    'Cyclic nucleotide phosphodiesterases reduce signaling by hydrolyzing cyclic nucleotides.',
  ],
);
@false_groups = (
  [
    'In mammals, olfactory receptors are ligand gated ion channels that open directly when an odorant binds.',
    'Most odorants are detected by receptor tyrosine kinases in olfactory neurons.',
  ],
  [
    'In olfaction, odorant binding decreases cAMP by directly inhibiting adenylyl cyclase.',
    'Olfactory transduction primarily depends on cGMP made by guanylyl cyclase.',
  ],
  [
    'In olfactory neurons, cAMP closes CNG channels to trigger depolarization.',
    'In olfaction, ion channels open only after cAMP is converted into cGMP.',
  ],
  [
    'Each olfactory sensory neuron expresses many different olfactory receptor genes.',
    'A single olfactory sensory neuron expresses every odorant receptor type.',
  ],
  [
    'Each odorant activates only one receptor, so smell has a one odor to one receptor code.',
    'Odor identity is determined only by odorant concentration, NOT by receptor patterns.',
  ],
  [
    'Salty taste depends on GPCR activation of adenylyl cyclase and cAMP.',
    'Salty taste is primarily detected by nuclear hormone receptors in taste cells.',
  ],
  [
    'Sour taste is caused by Na<sup>+</sup> entering taste cells through ENaC channels.',
    'Sour tastants are detected because they increase pH inside taste receptor cells.',
  ],
  [
    'Sweet tastants are detected mainly by direct passage of glucose through a membrane channel.',
    'Sweet taste is detected by a voltage gated sodium channel on taste cells.',
  ],
  [
    'Bitter tastants are detected by the same receptor used for salty taste.',
    'Bitter taste occurs only when taste cells take up large amounts of Ca<sup>2+</sup> from food.',
  ],
  [
    'Taste receptor cells do NOT communicate with neurons and act only as passive sensors.',
    'Taste transduction bypasses synapses and directly activates the cortex.',
  ],
  [
    'Signal amplification means each signaling step reduces the number of activated molecules.',
    'A cascade is less sensitive because it prevents second messenger production.',
  ],
  [
    'Phosphodiesterase makes cAMP from ATP and starts signaling.',
    'Phosphodiesterase increases cyclic nucleotide levels by synthesizing cAMP and cGMP.',
  ],
);

#==========================================================
# GLOBAL SETTINGS
#==========================================================

$topic = 'chemosensation (smell and taste)';
my $local_random = PGrandom->new();
$local_random->srand($problemSeed);
my @mode_choices = ("TRUE", "FALSE");
$mode = $mode_choices[$local_random->random(0, $#mode_choices, 1)];
$num_distractors = 4;
#==========================================================
# SELECT GROUP
#==========================================================

my (@selected_group, @opposite_groups);

if ($mode eq "TRUE") {
  $group_index      = $local_random->random(0, scalar(@true_groups)-1, 1);
  @selected_group   = @{ $true_groups[$group_index] };
  @opposite_groups  = @false_groups;
} else {
  $group_index      = $local_random->random(0, scalar(@false_groups)-1, 1);
  @selected_group   = @{ $false_groups[$group_index] };
  @opposite_groups  = @true_groups;
}

#==========================================================
# PICK CORRECT + DISTRACTORS
#==========================================================

my $correct_index = $local_random->random(0, $#selected_group, 1);
$correct = $selected_group[$correct_index];

my @available_group_indices = (0 .. $#opposite_groups);
my @selected_distractor_indices = ();

while (@selected_distractor_indices < $num_distractors && @available_group_indices > 0) {
  my $random_index = $local_random->random(0, scalar(@available_group_indices)-1, 1);
  push @selected_distractor_indices, splice(@available_group_indices, $random_index, 1);
}

@distractors = ();
foreach my $group_idx (@selected_distractor_indices) {
  my @group = @{ $opposite_groups[$group_idx] };
  my $distractor_index = $local_random->random(0, $#group, 1);
  my $distractor = $group[$distractor_index];
  push @distractors, $distractor;
}

@choices = ($correct, @distractors);

#==========================================================
# SHUFFLE CHOICES (SEED-STABLE)
#==========================================================

my @choice_indices = (0 .. $#choices);
my @choice_shuffled = ();
while (@choice_indices) {
  my $pick = $local_random->random(0, $#choice_indices, 1);
  push @choice_shuffled, splice(@choice_indices, $pick, 1);
}
@choices = @choices[@choice_shuffled];

#==========================================================
# RADIO BUTTONS WITH A/B/C/D/E LABELS
#==========================================================

$rb = RadioButtons(
  [@choices],
  $correct,
  labels        => ['A','B','C','D','E'],
  displayLabels => 1,
  randomize     => 0,
  separator     => '<div style="margin-bottom: 0.7em;"></div>',
);

#==========================================================
# PGML
#==========================================================

BEGIN_PGML

[@ $mode eq "TRUE" ? "Which one of the following statements is <span style='color: #127663;'><strong>TRUE</strong></span> about $topic?" : "Which one of the following statements is <span style='color: #ba372a;'><strong>FALSE</strong></span> about $topic?" @]*

[_]{$rb}

END_PGML

ENDDOCUMENT();