## TITLE('Difference Between the Leading Strand and the Lagging Strand in DNA Replication')
## DESCRIPTION
## Select the statement that is TRUE or FALSE about difference between the leading strand and the lagging strand in DNA replication.
## ENDDESCRIPTION
## KEYWORDS('difference between the leading strand and the lagging strand in DNA replication','true/false','multiple choice')
## DBsubject('Molecular 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 = (
[
'the leading strand is replicated continuously, while the lagging strand is replicated piecewise',
'the lagging strand is replicated piecewise, while the leading strand is replicated continuously',
'the leading strand is replicated continuously, while the lagging strand is replicated discontinuously',
'the lagging strand is replicated discontinuously, while the leading strand is replicated continuously',
'the leading strand is synthesized continuously,
whereas the lagging strand is synthesized in short fragments that are ultimately stitched together',
'the lagging strand is synthesized in short fragments that are ultimately stitched together,
whereas the leading strand is synthesized continuously',
],
[
'both the the leading strand and the lagging strand are synthesized in the 5′→3′ direction of the template strand',
],
[
'both the leading strand and the lagging strand require RNA primers',
],
[
'Okazaki fragments are DNA fragments synthesized on the lagging strand, but NOT on the leading strand',
],
[
'the leading strand is only synthesized by a single polymerase, while lagging strand uses more than one',
'the lagging strand is synthesized by multiple polymerases, while leading strand only uses one',
],
[
'the leading strand is synthesized in the same direction as the movement of the replication fork,
whereas the lagging strand is synthesized in the opposite direction',
'the lagging strand is synthesized in the opposite direction as the movement of the replication fork,
whereas the leading strand is synthesized in the same direction',
],
[
'both the leading strand and the lagging strand are synthesized by adding nucleotides to the 3′ end of the growing strand',
],
);
@false_groups = (
[
'the leading strand is replicated piecewise, while the lagging strand is replicated continuously',
'the lagging strand is replicated continuously, while the leading strand is replicated piecewise',
'the leading strand is replicated discontinuously, while the lagging strand is replicated continuously',
'the lagging strand is replicated continuously, while the leading strand is replicated discontinuously',
'both the leading strand and the lagging strand are replicated continuously',
'both the leading strand and the lagging strand are replicated discontinuously',
'both the leading strand and the lagging strand are replicated piecewise',
'the lagging strand is synthesized continuously,
whereas the leading strand is synthesized in short fragments that are ultimately stitched together',
'the leading strand is synthesized in short fragments that are ultimately stitched together,
whereas the lagging strand is synthesized continuously',
],
[
'the leading strand is synthesized in the 3′→5′ direction of the template strand,
while the lagging strand is synthesized in the 5′→3′ direction of the template strand',
'the lagging strand is synthesized in the 3′→5′ direction of the template strand,
while the leading strand is synthesized in the 5′→3′ direction of the template strand',
'both the the leading strand and the lagging strand are synthesized in the 3′→5′ direction of the template strand',
],
[
'the leading strand requires RNA primers, whereas the lagging strand does not',
'the lagging strand requires RNA primers, whereas the leading strand does not',
'the leading strand requires DNA primers, whereas the lagging strand does not',
'the lagging strand requires DNA primers, whereas the leading strand does not',
'both the leading strand and the lagging strand require DNA primers',
],
[
'Okazaki fragments are DNA fragments synthesized on the leading strand, but NOT on the lagging strand',
'Okazaki fragments are DNA fragments synthesized on both the leading strand and the lagging strand',
],
[
'the lagging strand is only synthesized by a single polymerase, while the leading strand uses more than one',
'a single polymerase creates both the leading strand and the lagging strand',
'multiple polymerase enzymes are required to synthesize the leading strand and the lagging strand',
],
[
'the lagging strand is synthesized in the same direction as the movement of the replication fork,
and the leading strand is synthesized in the opposite direction',
'the leading strand is synthesized in the opposite direction as the movement of the replication fork,
whereas the lagging strand is synthesized in the same direction',
'both the leading strand and the lagging strand are synthesized in the same direction as the movement of the replication fork',
'both the leading strand and the lagging strand are synthesized in the opposite direction as the movement of the replication fork',
],
[
'the leading strand is synthesized by adding nucleotides to the 3′ end of the growing strand,
whereas the lagging strand is synthesized by adding nucleotides to the 5′ end',
'the lagging strand is synthesized by adding nucleotides to the 3′ end of the growing strand,
whereas the leading strand is synthesized by adding nucleotides to the 5′ end',
'both the leading strand and the lagging strand are synthesized by adding nucleotides to the 5′ end of the growing strand',
],
[
'the leading strand is synthesized at twice the rate of the lagging strand',
'the lagging strand is synthesized at twice the rate of the leading strand',
'the leading strand is synthesized at half the rate of the lagging strand',
'the lagging strand is synthesized at half the rate of the leading strand',
'the leading strand is synthesized at four times the rate of the lagging strand',
'the lagging strand is synthesized at four times the rate of the leading strand',
],
);
#==========================================================
# GLOBAL SETTINGS
#==========================================================
$topic = 'difference between the leading strand and the lagging strand in DNA replication';
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 => '',
);
#==========================================================
# PGML
#==========================================================
BEGIN_PGML
[@ $mode eq "TRUE" ? "Which one of the following statements is TRUE about $topic?" : "Which one of the following statements is FALSE about $topic?" @]*
[_]{$rb}
END_PGML
ENDDOCUMENT();