The Transgenic Fly Virtual Lab: What Do You Know? Trivia Facts Quiz

External light cues can reset the flies' clock. This means that the flies' internal biological clock can be synchronized or adjusted by external light signals. Light is a powerful cue for regulating circadian rhythms in many organisms, including flies. Exposure to light can reset the phase of the flies' clock, allowing them to adjust their internal timing to match the external environment. This ability is important for flies to adapt to changes in day length and maintain proper timing for behaviors such as feeding, mating, and rest.

The construct DNA, after being incorporated into the genome of a fly, will reflect transcriptional activity without interfering with functions. This means that the construct DNA will be able to accurately indicate the level of gene expression without disrupting the normal functioning of the native genes. It will allow researchers to study gene activity without causing any unwanted alterations or disturbances in the biological processes of the fly.

The DNA sequence "transposase" is not found in the "construct DNA".

Both fireflies and per-Luc transgenic Drosophila produce the enzyme luciferase. Luciferase is responsible for the bioluminescent glow exhibited by these organisms. This enzyme catalyzes a reaction that produces light, allowing fireflies and per-Luc transgenic Drosophila to emit their characteristic glow. This glow is used by both species to attract mates and communicate with each other. The production of luciferase is a natural process in fireflies, while in per-Luc transgenic Drosophila, it is artificially introduced through genetic modification.

The correct answer is that the oscillations in the fly wing reset to the new schedule (days 8,9,10), which was 6 hours later than the original schedule (days 1, 2, 3). This means that the fly's biological rhythm adjusted to the altered day-night schedule and shifted its peak oscillations to occur 6 hours later than before. This indicates that the fly's internal clock is flexible and can adapt to changes in the environment.

The correct answer is that progeny with red-eyes are the result of matings in which the germ cell from one parent contains the transgene. This means that one of the parents carries a gene that causes red eyes, which is passed on to some of the offspring. It is not mentioned that red-eyed flies contaminate the experiment, a mutation occurs, or that red-eyed progeny occur in flies raised in constant darkness. Therefore, the only plausible explanation is the presence of the transgene in one of the parents.

The correct answer explains that light is produced in transgenic flies through the process of transcription of the transgene. This transgene produces luciferase, which then acts on luciferin to generate light. This process is similar to how light is produced in fireflies.

All the above situations could explain the result of only white-eyed progeny after completing a transgenic injection experiment. If the experimenter did not inject enough embryos, it is possible that only white-eyed progeny were observed due to a limited sample size. If the glass needle was accidentally broken and replaced with a new one while the embryos continued to develop, the delay in injections could have affected the outcome, resulting in white-eyed progeny. Additionally, if all the injections missed the germ cells in the posterior region of the embryos, it could lead to the observed result of only white-eyed progeny.

Injecting many embryos increases the chances of producing transgenic progeny because it increases the number of embryos that have the potential to successfully incorporate the construct DNA. By injecting a larger number of embryos, there is a higher probability that at least some of them will successfully integrate the DNA into their genome and develop into transgenic individuals. This increases the overall success rate of producing transgenic progeny.

When a fly embryo is injected with DNA and grows to adulthood, the injected DNA can be incorporated into the germ cells of the fly. This means that only the offspring that inherit these germ cells will have the injected DNA. Therefore, the experimentally useful per-luctransgenic fly is produced in only a few of the offspring of an injected embryo containing germ cells that have incorporated the injected DNA.

The given correct answer is "All the above." This means that all of the statements provided in the question are true. Measurements of per-luc gene expression from an individual fly wing have more variability than that observed from data averaged from 20 flies, they show similar trends compared with data from whole flies, and they dampen over time.

The reporter gene is designed to be easily detected and reflect the activity of the native gene. This means that when the native gene is active and producing its protein, the reporter gene will also be active and produce a detectable signal. This allows the experimenter to easily determine the level of activity of the native gene by measuring the activity of the reporter gene. It is important for the reporter gene to be easily detected so that the experimenter can accurately measure the activity of the native gene.

The correct answer is "embryo is too young to tolerate injection". This is because the other options listed - fluid loss due to wound at the injection site, injection of too much fluid causing the embryo to explode, and embryo becoming too dry - all provide valid reasons for why injected fly embryos fail to survive. However, the age of the embryo does not determine its ability to tolerate injection.

It is important to monitor the age of the fly embryos because cell membranes start forming around each nucleus in the multi-nucleated embryonic cell mass at approximately 30-60 minutes. Additionally, germ cells can incorporate DNA before differentiation, which begins when the embryo is approximately 30-60 minutes old. Embryos older than 30-60 minutes will not incorporate the DNA and will dilute the number of successfully injected flies. Therefore, monitoring the age of the fly embryos is crucial to ensure successful DNA incorporation and avoid wasting resources on embryos that are too old.

The maximal light output from the transgenic fly occurs when the promoter of the "period" gene is activated. This suggests that the "period" gene plays a crucial role in regulating the production of light in the transgenic fly. The activation of its promoter leads to an increase in the expression of luciferase, which is responsible for the light production. This finding highlights the importance of the "period" gene in the biological processes underlying light output in the transgenic fly.