Gregor Mendel never saw a gene, yet he concluded that some inherited factors were responsible for the patterns of inheritance he observed in peas. Similarly, maps of Drosophila chromosomes (and the very idea that genes are carried on chromosomes) were conceived by observing the patterns of inheritance of linked genes, not by observing the genes directly. Is it legitimate for biologists to claim the existence of objects and processes they cannot actually see? How do scientists know whether an explanation is correct?

Gregor Mendel never saw a gene, yet he concluded that some inherited factors were responsible for the patterns of inheritance he observed in peas. Similarly, maps of Drosophila chromosomes (and the very idea that genes are carried on chromosomes) were conceived by observing the patterns of inheritance of linked genes, not by observing the genes directly. Is it legitimate for biologists to claim the existence of objects and processes they cannot actually see? How do scientists know whether an explanation is correct?

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter13: Genes, Chromosomes, And Human Genetics

Section13.5: Non-mendelian Patterns Of Inheritance

Problem 1SB

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A graduate student performing studies on mutations in drosophila (fruit flies) discovered a strain of flies with a silent mutation in the gene controlling the shape of the wings. Further investigation has shown that this mutation is lethal in flies who are homozygote. Flies that are homozygote wild type or heterozygote can develop and are able to survive. What is a silent mutation (in your own words) and propose a hypothesis that could explain these observations using concepts learned. (a hypothesis is a proposed explanation based on an observation or observations)
Propose a hypothesis that could explain the following observation. A graduate student performing studies on mutations in drosophila (fruit flies) discovered a strain of flies with a silent mutation in the gene controlling the shape of the wings. Further investigation has shown that this mutation is lethal in flies who are homozygote. Flies that are homozygote wild type or heterozygote can develop and are able to survive.
If you continue with biological studies in the future, you are most likely going to carry out fruit fly experiments. Drosophila melanogaster are used in genetics labs due to how inexpensive they are, how visible their traits are, and their high reproductive rate. In Drosophila, the gene for red and white eye colour is found on the X chromosome. The allele for red eyes (XR) is dominant to the allele for white eyes (Xr). You are asked to cross a pure breeding white-eyed female with a pure breeding red-eyed male. What are the genotypes of the individuals involved in this cross? XRXR XRXr XRX- XrXr XRY XrY Genotype of the parent male Answer Genotype of the parent female Answer Genotype of the male offspring Answer Genotype of the female offspring Answer
Why are fruit flies considered a model genetic organism? Would humans fit this description?
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Drosophila can have 1, 2, or 3 stripes on their body. From previous experiments, you suspect that there are 2 genes (Gene C and Gene D) that control the number of stripes. A recent published paper described a similar stripe pattern in bees. Furthermore, in bees, Gene C is recessively epistatic to Gene D, are on different chromosomes, and the order of function is the following: C D 3 stripes → 2 stripes 1 stripe You therefore set out to test the hypothesis that Gene Cis also recessively epistatic to Gene D in Drosophila. To do so, you begin by crossing pure breeding 1-striped drosophila with pure breeding 3-stripped drosophila. To statically test your hypothesis, you proceed to perform a chi-square analysis on data obtained from the F1 X F1 cross. Using your hypothesis as your basis to analyze the results, fill the table below. Note: You do not have to calculate the chi-square or make a conclusion. Just fill the table. Observed Еxpected Нуpothesized Phenotypic ratio Phenotypes F2…
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