Name____________________________________                                  Date________________                  Hour________________

 

GENETICS COMPUTER SIMULATIONS – MULTIPLE ALLELIC SYSTEMS

GENETICS CD – 7      

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 discover how heredity is affected when there are more than two alleles for a trait.

 

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 “CORE INQUIRIES.”

6.        Click on “THREE’S A CROWD.”

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.        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.        How do the phenotypes of this new couple compare with those of the first couple?

 

 

 

2.        Describe the phenotypes of the F1 offspring (family 1.1)

 

 

 

 

 

3.        What pattern of inheritance seems to be operating here?__________________________________________

 

4.        Describe the phenotypes of the F1 offspring (family 1.2)

 

 

 

 

 

 

5.        How do the results in F1.2 differ from F1.1?________________________________________________

 

6.        Data table one:

 

FROM FAMILY F1.1

FROM FAMILY F1.2

BLACK X BLK

VERTICAL STRIPES

X

VERT STRPS

HORIZONTAL STRIPES

X

HORZ STRPS

WHITE

X

WHITE

PROGENY PHENOTYPES

BK x BK

--

--

--

--

BLACK

50

 

 

 

 

VERTICAL

37

 

 

 

 

HORIZONTAL

37

 

 

 

 

WHITE

2

 

 

 

 

TOTAL

 

 

 

 

 

 

 

7.        Given the data, which of the four phenotypes is homozygous?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8.        What is the ratio of this homozygous phenotype in those crosses in which it appears along with the other phenotypes?

 

 

 

 

 

 

 

 

 

 

 

9.        Do these ratios suggest that the phenotype of these homozygotes is determined by a dominant or recessive allele?

 

 

 

 

 

 

 

 

 

 

10.     Formulate a hypothesis to explain the mode of inheritance of the four phenotypes of the abdomen color.  You may want to conduct test crosses of individuals displaying the various phenotypes to the homozygous recessive.

 

 

 

 

 

 

 

 

 

 

 

 

11.     What is the mode of inheritance in this example?