Lab 7: Genetics of Organisms

  1. What is the life cycle of the fruit fly?
    • the eggs
    • the larval stage
    • the pupal stage
    • the adult stage
  2. Why should you make sure the females are virgins?
    to ensure a controlled mating
  3. Which cross involves the mode of nheritance being determined whent eh mutant characteristic is associated with teh X chromosome
  4. How do you distinguish males from females?
    • males: smaller/ dark blunt abdomen/ sex combs
    • females: larger/ lighter, pointed abdomen
  5. how do you find the chi square summation value?
    • (o-e)2
    • e
  6. What is the null hypothesis? What do you base it on?
    • THe null hypothesis is what we expect the results to be based on the cross.
    • Mono: 3:1
    • Dihy: 9:3:3:1
    • Sex- linked: 1:1
    • Intermediate: 1:2:1
  7. How do you know whether to accept or reject the null hypothesis?
    If the chi square value is greater than our summation value, then we can accept hte null hypothesis by saying that maybe chance caused a deviation from numbers
  8. Why was it necessary for the females of the P generation to be virgins?
    Since nonvirgins hold alot of sperm in their receptacles, we would not be able to control the experiment because we wouldnt know who the father is. It helps us ensure certainty of paternity.
  9. Why was it not necessary to isolate virgin females for the F1 cross?
    It was not necessary to isolate the virgin females because they are virgins and therefore don't have sperm in their receptacles. It'd be pointless to isolate them because it is the virgins we need for the experiment. They have just hatched and so we know for a fact they are virgins. Also, the male flies they were exposed to were also of the F1 generation. So, we'd not have to isolate them because the traits are the ones we are willing to cross
  10. Why were the adult flies removed from the vials at weeks 2 and 4?
    they were removed so they would not mate with the next generation- their offspring.
  11. The __ tells us that there is no statistically significant difference between the observed and expected data.
    null hypothesis
  12. What row would you use for probability?
Card Set
Lab 7: Genetics of Organisms