After performing a three points experiment your college obta

After performing a three points experiment, your college obtains these results. They are Confused that only six different phenotypes were present, rather than die expected eight Can you explain this result? What phenotypes are missing, and how many of them would you expect to see out of total of 125? (Show your work) Incorporate the following frequencies into a single genetic map. Your map should include only most accurate data (this means that not all the listed used in your final answer).

Solution

The missing phenotypes are

l + n

+ m +.

One of the reasons for the missing phenotypes means that the genes are present very close to each other resulting in no double cross overs.

Another reason maybe that gene l is present in between n and m. and there may have occured a recombination between n and l. From the given table we can deduce that there is a distance of .03 mu between m and l and there is a distance of .16 mu between n and l. This means that the total distance between m and n is .19 mu.

Now calculating the expected number of missing phenotypes we multiply total number of offsprings with the genetic distance between m and n. This will be

125 * .19

= 24

Hence, the number of missing phenotypes that can be expected is 24.