Name____________________________________ Date________________ Hour________________

GENETICS COMPUTER SIMULATIONS - PROBABILITY

GENETICS CD - 2

Directions: Obtain a CD entitled "Biology Explorer 3.04 Genetics" and a coin from your instructor. Go quietly to the Media Center computer lab. Insert the CD and then complete the following activity. Return the CD to your instructor when finished.

PURPOSE: To observe how mathmatical probability relates to the inheritance of traits.

PROCEDURE:

    1. Go to the START MENU.
    2. Place your cursor on PROGRAMS.
    3. Move your cursor to "LOGAL Biology Teacher."
    4. Click on GENETICS MAIN MENU.
    5. Click on "EXPLORATIONS."
    6. Click on "GENETIC PROBABILITY."
    7. <<At this point, the arrows to move around through the program are at the very bottom of the screen. We may have to grab and drag the Start menu tool bar downward until we can’t see it any longer in order to uncover the arrows we need.>>
    8. Use the arrows to move to page four in the program.
    9. Follow the directions on each page to complete the exercise. Blue "hyperlinked" words in the directions text can be clicked on to perform certain functions.

QUESTIONS AND DATA TABLES:

  1. Data table one: POPULATION SIZE = 10

TRIAL

FEMALES

MALES

RATIO

1

2

3

4

5

2. Data table two: POPULATION SIZE = 100

TRIAL

FEMALES

MALES

RATIO

1

2

3

4

5

3. Data table three: POLULATION SIZE = 1000

TRIAL

FEMALES

MALES

RATIO

1

2

3

4

5

  1. In which sample size was there the greatest fluctuation of the observed ratio? ________________________________
  2. Whick of the three different sample sizes gave the best approximation of the expected ratio?_____________________________

    3.  

  3. In conducting experiments, which involve probabilities, what can we conclude about the importance of sample size?

    4.  

     

  4. Now consider the following problem. Two offspring will be born into a family. What is the probability that these two offspring will both be females? What is your prediction? (Write the respose in the space to the right of data table four…)
  5. Data table four:
    6.

    TRIAL

    COIN TOSS M/F

    SIMULATION M/F

    BOTH FEMALE

    YES/NO

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10

    TOTAL

  6. Data table five:
    7.

    OBSERVED NUMBER

    PERCENTAGE OF TOAL

    MALE

    (COIN TOSS)

    FEMALE

    (COIN TOSS)

    MALE

    (SIMULATION)

    FEMALE

    (SIMULATION)

    TWO FEMALE OFFSPRING

  7. What is the probability that these two offspring will be females? What is your prediction?________________________________

11. Data table six:

FRACTION

%

MALE-MALE

MALE-FEMALE

FEMALE-MALE

FEMALE-FEMALE

12. Does the ratio of two-female families come closer to the expected probability when we increase the sample size?