Hardy-Weinberg Problems Tutorial
(a computer program written in Q-BASIC
and meant to run on IBM compatible computers)
What will the program do?
This program will quiz students
on their ability to solve mathematical problems dealing with the
Hardy-Weinberg principle. There are 7 basic types of Hardy-Weinberg
Problems which are randomly chosen by the program. A student may
think that he or she is getting the same problem, but the program
does try to 'mix' the 7 problem types and does try
to insert different numbers into the problems. The program will
keep track of the number of problems attempted, the number of
problems missed on the first attempt, and the percentage of problems
correctly answered on the first attempt.
What doesn't the program do? The program does not
make a hard copy of anything. The program does not permanently
save anything. There will be no permanent or retrievable record
of how well each student performed on the tutorial.
What does the student do? The student should know the concept
of Hardy-Weinberg. The student will sit at the computer with a
hand-held calculator and pencil and paper. The student will run
the Q-BASIC program. The student will carefully follow the screen
directions. The student will be shown 2 sample problems and be
asked to answer them. The program will show the student a way
to solve each of the 2 sample problems. After the 2 sample problems,
the student may start the 7 problem types of the tutorial. The
student may quit the tutorial at the completion of any problem.
In the event of an incorrect student response, the program will
give the student 2 additional 'tries' (a total of
3 attempts) at answering the same question before disclosing the
correct numerical response to the student.
How does a teacher start the program? There are 2 methods
by which one can start this program. Directions are given for
computers with a 3.5" disk drive. However, this program can
be made to easily run on computers which do not have that size
drive. Perhaps you can ask the knowledgeable computer science
person at your school for assistance.
The teacher may type the program, word for word, line for line,
punctuation mark for punctuation mark, into the computer. If
one chooses to use this method, it is very important that no mistakes
are made in typing the program into the computer. In order to
type in this program, the following steps must be followed.
- Turn on the IBM compatible computer. If you are at the C:\>
prompt, stay there. If you are in WINDOWS, click on the '-'
sign in the upper left hand corner of the PROGRAM MANAGER -[MAIN]
screen. Next, move down to the CLOSE choice and click on it. Next,
choose to exit the WINDOWS session when given that choice by clicking
on OK. The point is, by any means possible to you, mouse or no
mouse, get the C:\> prompt on the screen.
- Once the C:\> prompt is obtained, type in the word QBASIC
or qbasic. The QBASIC screen should appear on your monitor. Move
to the ESC part of the screen and click on it to clear the first
dialog box. Just follow the screen directions to clear the dialog
- A 'clean' screen should now appear on the monitor.
Once this clean screen is obtained, the QBASIC program can be
typed. Be certain to push the <ENTER> key after typing in
each and every numbered line. The more carefully the program is
typed in, the more likely it will run without any problems.
- After the program is typed in, click the cursor on the FILE
command in the upper left hand corner of the screen. Select SAVE
AS and click on it. At the FILE NAME prompt, type in the word
CHIPSTER as the file name. Move to the OK prompt at the bottom
of the screen and click on it. The program is now saved to the
hard drive (DRIVE C) with the name CHIPSTER.
- It is recommended that this program also be saved on a 3.5"
diskette formatted for the IBM compatible clones. It can also
be saved on other sizes of diskettes but those directions will
not be given here. To save to a 3.5" IBM formatted disk,
you should have just completed steps a, b, c, and d. There are
other ways to save it to disk, but they will not be discussed
here. Perhaps you can ask the knowledgeable computer science person
at your school for assistance. At the completion of step d, the
program listing should be on your monitor screen. Click the cursor
on the FILE command in the upper left hand corner of the screen.
Move to SAVE AS and click on it. Under the DIRS/DRIVES box, there
are two little arrows. One moves up and one moves down. Click
many times on the down arrow to reach [-A-] and click on it. Then
click on OK. On the same screen, at the FILE NAME prompt, type
in the name of the program, CHIPSTER, and click on OK. At this
point, the program should now be saved on both the hard drive
(DRIVE C) and the 3.5" diskette in DRIVE A. When the light
is not 'on' near DISK A, remove the diskette from
DRIVE A. You may now safely turn off the computer.
- In order to run the program, perform steps a and b (above).
To prevent students from tampering with (changing and invalidating)
the program, it is recommended that you keep the program on the
3.5" diskette. Do not allow the students to have access to
the diskette. You can load the program from the diskette and then
remove the diskette from the computer to protect the diskette.
- Properly insert the diskette into DRIVE A. Click on the FILE
command in the upper left hand corner of the screen. Click on
the OPEN option. Under the DIRS/DRIVES box, there are two little
arrows. One moves up and one moves down. Click many times on the
down arrow and select [-A-], which is DRIVE A, and click on it.
Then click on OK. At the FILE listing, move the cursor to CHIPSTER
and click on it. Then click on the OK. The program listing for
CHIPSTER should appear on the screen.
- Move the cursor to the RUN command at the top of the screen.
Click on the RUN command and then the START command and the program
should begin executing.
- If you would like to return to the WINDOWS screen, first simultaneously
press the CTRL and BREAK keys. Then move the cursor to the upper
left hand corner of the screen and click on FILE. Choose the EXIT
option and click on it. This should present to you the C:\>
prompt. At this point, type in the word WIN and then the <ENTER>
key. You should now see the familiar WINDOWS on your monitor screen.
Alternatively to METHOD #1, the teacher may send me a blank 3.5"
diskette formatted for IBM. I shall load the program on the blank
disk and return it. Please be certain to include your return address
if you choose to use this method of obtaining this program. My
address is given in program lines 40 through 70 in the program
listing appearing below this paragraph. Upon receipt of the diskette
from me, go to step 'f' in METHOD #1 (above) in order
to RUN the program.
20 PRINT ' HARDY-WEINBERG PROBLEMS TUTORIAL'
30 PRINT ' written by'
40 PRINT ' Robert W. Reynolds'
50 PRINT ' The Casady Schools'
60 PRINT ' 9500 North Pennsylvania Avenue'
70 PRINT ' Oklahoma City, Oklahoma 73120'
80 PRINT : PRINT : PRINT : PRINT : INPUT 'Push <ENTER>
to continue.'; z$
83 CLS : PRINT : PRINT : PRINT : PRINT
84 PRINT 'Throughout this tutorial, remember to push <ENTER>
85 PRINT 'having entered your answer. Also, to leave the
87 PRINT 'simultaneously the CTRL button and the BREAK
88 PRINT 'Then, choose FILE in the upper left hand corner
of the screen and'
89 INPUT 'make the correct choices. Press <ENTER>
to continue.'; z$: CLS
90 PRINT 'Welcome to the HARDY-WEINBERG PROBLEM TUTORIAL.
100 PRINT 'have a pencil and paper and a calculator that
can do square root.'
110 PRINT 'You should be quite familiar with the HARDY-WEINBERG
120 PRINT 'concepts and the following HARDY-WEINBERG equations:'
130 PRINT : PRINT 'p + q = 1 and pp
+ 2pq + qq = 1'
140 PRINT : PRINT : PRINT 'If you do not have a working
knowledge of these 2'
150 PRINT 'equations, ask your teacher for some advice
on where to read about'
160 PRINT 'them. It may be unwise for you to continue
170 PRINT : PRINT : INPUT 'push <q> to quit or <c>
to continue.'; y$
175 IF y$ <> 'c' AND y$ <> 'q'
THEN GOTO 170
180 IF y$ = 'q' THEN CLS : GOTO 10
190 CLS : PRINT 'Let's start with a sample problem:'
200 PRINT : PRINT 'If the frequency of a recessive allele
in a population is'
210 PRINT '0.16 (or 16%), what is the expected frequency
of the dominant'
220 PRINT 'allele?'
230 PRINT : PRINT : INPUT 'Type your answer in decimal
240 PRINT : PRINT : IF a <> (.84) THEN PRINT 'Your
answer is incorrect.'
245 IF a = (.84) THEN PRINT 'Congratulations.'
250 PRINT : PRINT 'The correct answer is 0.84 (or 84%).
260 PRINT 'tutorial, give the answers in decimal format
and not as'
270 PRINT 'percentage. To find the answer, you should
have used the'
280 PRINT 'equation: p + q = 1.': PRINT : PRINT
290 PRINT 'From the problem, we know that q = 0.16. From
the equation we'
300 PRINT 'know that p + q = 1. By substituting the value
of q into the'
310 PRINT 'equation, we arrive at:': PRINT
320 PRINT 'p +( 0.16) = 1. This is equivalent to p = 1
- (0.16) or p = 0.84'
330 PRINT : PRINT : INPUT 'Press <ENTER> enter to
continue.'; z$: CLS
340 PRINT 'Let's try one more sample problem before
we start the tutorial'
350 PRINT 'problems.': PRINT : PRINT
360 PRINT 'If the frequency of the homozygous dominant
genotype is 0.49'
370 PRINT '(49%) and the frequency of the homozygous recessive
380 PRINT 'is 0.09 (9%), what is the expected frequency
of the heterozygous'
390 PRINT 'genotype?': PRINT : PRINT
400 INPUT 'Type your answer in the decimal format.';
410 IF a <> .42 THEN PRINT 'Your answer is incorrect.'
420 IF a = .42 THEN PRINT : PRINT 'Congratulations.'
430 PRINT : PRINT 'The correct answer is 0.42 or 42%.
440 PRINT 'tutorial, give the answer in decimal format
rather than as a per'
450 PRINT 'centage. To find the answer you should have
used the equation:'
460 PRINT : PRINT ' pp + 2pq + qq = 1'
470 PRINT : PRINT : PRINT 'From the problem, we know that
pp = 0.49 and that'
480 PRINT 'qq = 0.09. By substituting these 2 values into
the equation, we'
490 PRINT 'arrive at:': PRINT '
( 0.49) + 2pq +( 0.09) = 1'
500 PRINT : PRINT 'Solving for 2pq, which is the frequency
of occurrence of'
510 PRINT 'the heterozygous genotype, one can see that:'
520 PRINT : PRINT ' 2pq = 1 - (0.49 + 0.09)'
530 PRINT : PRINT 'Therefore: 2pq = 0.42'
535 INPUT 'Press <ENTER> to continue.'; y$:
540 PRINT : PRINT 'You have completed the 2 practice problems.
If you had'
550 PRINT 'difficulty with the 2 sample problems, you should
ask your teacher'
560 PRINT 'for advice on whether to proceed further.':
PRINT : PRINT
600 CLS : PRINT 'You are now ready to begin the tutorial.
You will not be'
610 PRINT 'given any solutions so be certain to have your
620 PRINT 'pencil and paper nearby. Ask your teacher for
assistance if you'
630 PRINT 'are really puzzled about an answer.'
640 PRINT : PRINT 'If you wish to quit the program, type
650 INPUT 'To continue the program, type <c>.';
660 IF c$ = 'q' THEN GOTO 10
700 RANDOMIZE TIMER: x = ((INT(RND * 7) + 2) * 1000): n = 0
710 IF w > 0 THEN PRINT : PRINT 'If you wish to quit
the program, type <q>.'
720 IF w > 0 THEN INPUT 'To continue the program, type
<c>.'; c$: CLS
730 IF w > 0 AND c$ = 'q' THEN GOTO 9600
740 w = w + 1: REM w counts number of problems attempted
745 CLS : PRINT 'PROBLEM NUMBER'; w: PRINT : PRINT
: PRINT : PRINT
750 IF x = 2000 THEN GOTO 2000
760 IF x = 3000 THEN GOTO 3000
770 IF x = 4000 THEN GOTO 4000
780 IF x = 5000 THEN GOTO 5000
790 IF x = 6000 THEN GOTO 6000
800 IF x = 7000 THEN GOTO 7000
810 IF x = 8000 THEN GOTO 8000
2000 REM: PROBLEM #1
2010 RANDOMIZE TIMER: x% = (INT(RND * 100)): PRINT : PRINT
2020 PRINT 'If the frequency of the dominant allele in
a population is';
2030 PRINT x% / 100; ','; 'what is the frequency
of the recessive allele in'
2040 INPUT 'the same population'; b: a = ((100 -
x%) / 100)
2050 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
2060 IF n > 0 AND n < 3 THEN GOTO 2020 ELSE GOTO 700
3000 REM PROBLEM #2
3010 RANDOMIZE TIMER: x% = (INT((RND * 9) + 1))
3020 PRINT 'If the frequency of the recessive allele in
the gene pool is'
3030 PRINT x% / 10; ', what is the frequency of the homozygous
3040 INPUT 'genotype in the population'; b: a = (x%
/ 10) ^ 2
3050 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
3060 IF n > 0 AND n < 3 THEN GOTO 3020 ELSE GOTO 700
4000 REM:PROBLEM #3
4010 RANDOMIZE TIMER: x% = (INT((RND * 10) + 1) ^ 2)
4020 PRINT 'If the frequency of the homozygous recessive
4030 PRINT 'a population is'; x% / 100; ',
what is the frequency of the';
4040 INPUT ' recessive allele in the gene pool of that
4050 a = (SQR(x% / 100)): IF b = a THEN GOSUB 9500 ELSE GOSUB
4060 IF n > 0 AND n < 3 THEN GOTO 4020 ELSE GOTO 700
5000 REM:PROBLEM #4
5010 RANDOMIZE TIMER: x% = (INT((RND * 10) + 1) ^ 2)
5020 PRINT 'If the frequency of the homozygous recessive
phenotype in the'
5030 PRINT 'population is'; x% / 100; ', what
is the frequency of the'
5040 INPUT ' dominant allele in the gene pool of that population';
5050 a = (1 - (SQR(x% / 100)))
5060 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
5070 IF n > 0 AND n < 3 THEN GOTO 5020 ELSE GOTO 700
6000 REM:PROBLEM #5
6010 RANDOMIZE TIMER: x% = (INT(RND * 9) + 1)
6020 PRINT 'If the frequency of the dominant allele is
found to be'
6030 PRINT x% / 10; ', what is the frequency of the heterozygous
genotype in the'
6040 INPUT 'same population'; b: a = 2 * ((x%) *
(10 - (x%))) / 100
6050 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
6060 IF n > 0 AND n < 3 THEN GOTO 6020 ELSE GOTO 700
7000 REM:PROBLEM #6
7010 RANDOMIZE TIMER: x% = (INT((RND * 10) + 1) ^ 2)
7015 RANDOMIZE TIMER: y% = (INT((RND * 10) + 1) ^ 2)
7016 IF ((SQR(x% / 100)) + (SQR(y% / 100))) <> 1 THEN GOTO
7020 PRINT 'If the frequency of the homozygous recessive
7030 PRINT x% / 100; 'and the frequency of the homozygous
7040 PRINT 'is'; y% / 100; ', '; 'what
is the predicted frequency of the'
7050 INPUT 'heterozygous genotype in the population';
7055 a = (2 * ((SQR(x%)) * (SQR(y%)))) / 100
7060 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
7070 IF n > 0 AND n < 3 THEN GOTO 7020 ELSE GOTO 700
8000 REM:PROBLEM #7
8010 RANDOMIZE TIMER: x% = (INT((RND * 10) + 1) ^ 2)
8015 IF 2 * (x% / 100) > 1 THEN GOTO 8010
8020 PRINT 'If the frequency of the homozygous dominant
genotype and the'
8030 PRINT 'heterozygous genotype are both equal to the
8040 PRINT x% / 100; ',what is the predicted frequency
of the homozygous'
8050 INPUT 'recessive genotype'; b: a = (1 - (2 *
x% / 100))
8060 IF b = a THEN GOSUB 9500 ELSE GOSUB 9000
8070 IF n > 0 AND n < 3 THEN GOTO 8020 ELSE GOTO 700
9000 REM:ERROR MESSAGE
9010 CLS : PRINT : PRINT 'You have answered incorrectly.
You are given'
9020 PRINT '3 total chances to answer correctly before
being given the'
9030 INPUT 'correct answer. Push <ENTER> to continue.';
9040 n = n + 1: REM counter
9050 IF n = 1 THEN v = v + 1: REM v counts number of first time
9060 IF n = 2 THEN PRINT : PRINT 'Only 1 more chance.'
9065 IF n = 3 THEN PRINT 'You have erred on your 3 attempts.'
9070 IF n = 3 THEN PRINT : PRINT 'The correct response
is'; a; '.'
9080 IF n = 3 THEN PRINT : PRINT 'Better luck next time.'
9090 PRINT : IF n = 3 OR n = 2 THEN INPUT 'Push <ENTER>
to continue.'; r
9100 CLS : RETURN
9500 REM:CONGRATULATORY MESSAGE
9510 n = 0: PRINT : PRINT 'You have answered correctly.
9520 PRINT : INPUT 'Press <ENTER> to continue.';
r: CLS : RETURN
9600 REM :ENDING MESSAGE
9610 CLS : PRINT 'You have attempted '; w; 'problems.
You have missed'
9620 PRINT v; 'of them on the first attempt.': PRINT
9630 PRINT 'Your % correct on first attempt was';
((w - v) / (w)) * 100; '.'
9640 PRINT : INPUT 'press <ENTER> to continue';
i: w = 0: n = 0: GOTO 10