Introduction:
The purpose of this laboratory activity is to investigate the Hardy-Weinberg Law of Equilibrium using the fruit fly Drosophila melanogaster. According to the Hardy-Weinberg Law of equilibrium, allele frequencies should remain the same in large populations that do not experience gene flow, mutations, nonrandom mating, and natural or artificial selection. We will be studying the alleles that determine wing shape, either normal (wild type) wings or vestigial wings. Vestigial females will be crossed with equal numbers of vestigial males and wild type males. I this population is at Hardy-Weinberg equilibrium we would predict an equal number of wild type and vestigial offspring in the next generation.
However, according to Bastock and Manning
An equal number of females and each type of male were introduced into each test tube, but in my own sample and those of others in the class there were mortalities throughout the experiment. Both some of the original flies and some offspring died during the experiment which could have influenced the results. If a vestigial fly died before it could mate that would give the wild type males an advantage in mating and producing a greater number of offspring. This would also be the case if any flies were harmed at any time during the mating period. To try and combat this problem the next time this experiment is done a larger number of male fruit flies could be used or more samples taken to try and reduce extremes in the data.
Studying fruit fly mating behavior is very important because their generation length is so short and reproduction happens rapidly. In science, these fruit flies can be used to study genes and mutations relatively quickly because of the limited life span. Knowing mating behaviors can help scientists better understand their results and improve their experiment designs to reduce
Test 4: All three phenotypic frequencies saw a reduction in their number as the homozygote fishes saw a reduction in their number and were not able to pass on their alleles to create either their colored fish or a heterozygote. Both yellow and blue allele frequencies decreased by the same
This experiment was designed to illustrate the process of evolution through the use of Origami Birds. It was evident at the conclusion of the experiment that Origami Birds with a smaller in circumference front wing placed 3 centimeters from the end of the straw and larger in circumference back wing placed 3 centimeters from the end of the straw flew further than the Generation 0 birds with the same circumference front and back wings. Our results also indicated that birds with their wings positioned differently than 3 centimeters from either end of the straw did not fly as far as those who were positioned at that 3 centimeter mark. Generation 0's best flyer produced a distance of 2.08 meters with a 3x20 and 3x20 wing ratio. Generation 1's best
Sexual reproduction in the Venus flytrap is no different than the other plants. Venus flytraps can be self-pollinated, meaning that you can fertilize the pistil with pollen from its own anthers. A few days after fertilization, the flowers will wither and die. The seed matures in 4-6 weeks after pollination occurred. “As the seed has matured, the tiny ovary turns jet black; about 1.5mm in length”. If the pollination attempt was unsuccessful, there will only be dead plant material.
The purpose of the first experiment, Ebony vs. Vestigle was to see how many of the offspring had normal bodies and normal wings, normal bodies and vestigle wings, ebony bodies and normal wings, and ebony body and vestigle wings. The purpose of the second experiment White vs. Wild was to see how many of the offspring were red eyed male, white eyed male, red eyed female, and white e...
We were unable to reject the null hypothesis with our results from trial one. The calculated chi value was less than the critical value. Our calculated chi value was 5.00, which is 0.99 less than the critical value at 5.99. Although the results did show a trend that followed our initial prediction where bright light is preferred amongst the house crickets, the statistical results demonstrated that these observations were mainly random occurrences. Initially, before calculating our statistical results, we thought that the crickets picked the brighter region because it is often associated with heat; since the house cricket needs heat in order to develop and survive, we thought that this was an important factor that may influence the cricket’s choice in preferable section. During our experiment, we also observed that many of the crickets were not really decided when placed into our experimental setup. Many of the house crickets only ran around in circles in the stacking dish. After the two minute timeframe, we marked the location of each cricket and most of the crickets rema...
There are alternative explanations for the data collected and some limitations to the experiment. Sizes varied among the house crickets which may have caused some of the pairs of house crickets to be unequal in size. The cricket that was larger had a better chance to attack and win more often compared to the smaller cricket. Another limitation for this experiment is that many crickets died before the experiment could be conducted. Due to the small container size, the house crickets were also stressed out because they were not contained in their natural
Females like to choose mates who have very bright colors as it is a sign of the male’s good health and vigor. The natural and sexual selection can affect populations in three ways: directional (environmental conditions change in a consistent direction; one extreme of phenotypes is favored), stabilizing (environmental conditions are relatively constant; intermediate phenotype is favored), and disruptive selection (environment has more than one type of useful resource; both extremes of phenotypes are favored). An example of directional selection is pesticide resistance since only the insects with a resistance are favored; an example of stabilizing selection is that the smallest lizards have a difficulty defending their territory whereas the largest lizards are most likely to be eaten by owls; an example of disruptive selection are the black-bellied seedcrackers since they either have a large beak (which they can use to eat had seeds), or a small beak (which allows them to eat soft seeds). Disruptive selection shows a balanced polymorphism, which is when two or more phenotypes are maintained in a
Some individuals have developed different traits to help them in the process of intra-sexual competition. The organisms with more distinctive traits have greater reproductive success. More genes of those traits are then ‘selected’ and are passed onto the offspring of the organisms. Throughout time variability in these traits becomes
5.Use a test-cross. Mate the unknown fly to a known homozygous recessive. Think about the results if the fly was heterozygous vs. if it were homozygous dominant.
In this lab, we experimented on wingless samples of Drosophila. Now, there are two different types of fruit flies as discovered by Marla Sokolowski; one walks around more than the other. The names Rover and Sitter are given respectively. The main difference between the two types are demonstrated when feeding. Speaking of which, fruit flies don’t feed on the fruit itself, what they feed on are the bacteria that grow on rotting fruit. The fruit flies find food to eat via the use of chemoreceptors, which alert the fly that there is food nearby by stimulating its sense of smell. They will then fly over to the food source and start feeding. Now this is where the difference between Rovers and Sitters comes to play. Let’s say the fruit fly runs out
17. Fruit flies normally have eight chromosomes. The diagram below shows the result of meiosis in three fruit flies to produce gametes with the number of chromosomes indicated. The male then mates with both female A and female B to produce three zygotes (1, 2, and 3).
Flies that began mating on hawthorns now have a population that mate on apples. 2. What is the difference between a.. What is the difference between polygenic inheritance and pleiotropy? Polygenic:
The F2 punnett square shows that there should not be a female fly that has apterous wing mutation. Our observed experiment showed that female flies are capable of forming in the F2 Generation. Therefore, the mutation is located on autosomal chromosomes. In trial 1, the p value is not significant. This could be due to the fact that the male to female ratio in the F1 generation was unequal. In trial 2, the p value is significant and likely due to chance. The probability error is between 1 % and 5%.
The Hardy-Weinberg theorem states that the frequency of alleles and genotypes in a population’s gene pool remain constant over the generations unless acted upon by agents other than sexual recombination. For example, take a population of mice that consists of 1,000 members. A specific allele, albino allele, is recessive within this species. 80% of the population expresses the normal phenotype- brown coloring, while the remaining 20% are albino. 640 members of the population have the genotype AA, 320 have Aa, and 40 have aa. If completely random mating were to occur, there would be an 80% chance that a gamete would bear the normal allele, A, and a 20% chance that the gamete would bear the albino allele, a. The resulting offspring will display the following genotype ratios: AA will have 64%, Aa 32% (the chance of the offspring having the A allele is 96%), and aa 4%. The offspring have the same genotype ratio as their parents. This example was one of Hardy-Weinberg equilibrium. The next generation will express the same genotype ratio as their parents, and so on. But what exactly is needed to create Hardy-Weinberg equilibrium? (Basically, a population in Hardy-Weinberg equilibrium s not evolving in any way.) Five specific factors are needed to create Hardy-Weinberg equilibrium within a population- a very large population, isolation from other populations, no net mutations, random mating, and no natural selection.
Conclusion for class mono-hybrid cross: The p value 0.222 was in the non-significant range in the chi square table. The null hypothesis was therefore correct. The colors of the eyes are sex linked due to the equality in the amount of phenotypes given to both male and female.