home *** CD-ROM | disk | FTP | other *** search
- CREATURE CROSS (Version 1)
- ==========================
- Public Domain By Lance Peters
-
- Requires 160k for Screen Memory and 32k for System sprites
-
- A basic knowledge of inheritance, as found in most school biology text books,
- is required to make proper use of this program. However for those with no
- biological background I have included some basic information on the file
- named "Lesson".
-
- The program simulates breeding experiments which would normally be carried
- out using organisms such as fruit flies (Drosophila). However although there
- is no substitute for such real experiments they are very time consuming and
- only a limited number of crosses are practical. Using a simulation you can
- breed to your hearts content. By selecting the traits for investigation the
- program can demonstrate aspects of inheritance from simple monohybrid
- crosses up to gene mapping using triple test crosses. This version does not
- include aspects such as lethal genes, multiple alleles,continuous variation,
- epistasis or other effects of gene interaction. These might be possible on an
- extended version.
-
- The creatures are called Slygrons and come from the planet Eipa3. They are
- useful for studying the principals of Mendelian Inheritance since they are
- small (1cm tall) and easily kept. They breed very rapidly with up to 40
- offspring from each mating. Their mechanism of inheritance is remarkably
- similar to mammals of Earth. They have 6 chromosomes (2 pair of autosomes and
- a pair of sex chromosomes). The male is the heterogametic sex (ie.XY) and he
- can be recognised by the sexual spurs on his heels (used in fighting).
- There are 9 easily observable traits which show discontinuous variation and
- you can select the phenotype of each of the initial parents (The P1 male and
- female will be homozygous for all 9 pairs of alleles).
- A breeding program can be performed as far as the F3 generation and a test
- cross can be performed on any individual animal in any of these generations.
- A Chi-squared test can be carried out to see if an observed ratio differs
- significantly from the expected ratios.
- Some of the genes show complete dominance, some show partial or co-dominance,
- some are sex linked (present only on the Y chromosome) and many traits will
- show autosomal linkage (as there are 3 pairs of homologous chromosomes there
- are 3 linkage groups). By performing appropriate crosses it should be
- possible to determine the nature of the genes and if you are really dedicated
- you can map the genes on each of the chromosomes. Mapping requires test
- crosses to determin the % recombination in the case of linked genes (NB
- unlike Drosophila crossing over occurs in both sexes). For those who wish to
- 'cheat' the answers are given at the end of this text.
-
- Running the Program:
- All operations except for the Chi-squared test are carried out using the
- mouse. Clicking 'select' on a Buff coloured or orange box will execute the
- operation. To select or count the number of individuals,'click' on the
- sprite. To use the counter,'click' on 'ON' to activate it. There are 8 store
- boxes for counts and the one highlighted in white is the current one. Click
- on box to select another. 'C' clears the current box. 'CA' clears all the
- boxes. 'OFF' returns to the main menu. Note that when the counter is
- reselected it is automatically cleared.
-
- Conditions of Use:
- The program may be freely distributed provided.
-
- 1.This file is included with the program.
-
- 2.No charge is made (except for media and postage or in the case of a disc
- sold for charity).
-
- If you find the program useful for teaching purposes and would like to modify
- it or have suggestions for improvement or find any bugs (other than the
- Slygrons) please let me know. If you send me a S.A.E I will send you an
- explanation of how it works. A desktop multitasking version would be nice
- but I have not got to grips with the WIMP yet!
-
- Address: Mr L M Peters,
- 4 Coatguard Cottages,
- Helford Passage,
- Mawnan Smith,
- Falmouth,
- Cornwall TR11 5LB
-
-
- ANSWERS !!!!
-
- TRAIT DOMINANT CHARACTER
- Horn type Upward horn
- Body colour Purple body
- Antenna length Co-dominance
- Antenna type Hairy
- Leg size Fat legs
- Leg colour Red legs
- Eye colour Dark blue eyes
- Eye shape Co-dominance
- Proboscis length Long proboscis
-
- Sex linked traits = Body colour and Antenna type
-
- Autosomal linkage (Numbers indicate the map distance between the genes)
-
- Linkage group 1
-
- <Antenna length> 11 <Proboscis length> 4 <Eye colour> 18 <Leg size>
-
-
- Linkage group 2
-
- <Eye shape> 6 <Horn type> 14 <Leg colour>
-
-
- Linkage group 3 (On the X chromosome)
-
- <Antenna type> 23 <Body colour>
-
-