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25 Sep 2018

When Gregor Mendel was developing his ideas of inheritance of characteristics, molecular genetics was not yet discovered. Explain in your own terms, why his two most important ant laws have stood the test of time. What assumptions about them were correct? Describe a scenario in which patterns of inheritance did NOT adhere to Mendelian genetics.

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Keith LeannonLv2

27 Sep 2018

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Related questions

1. What was Darwin's theory of pangenesis and how did it fit his model of blending inheritance? How did it allow for the influence of the environment on hereditary characters?

2. How was the idea of environmental influence criticized by Weismann? What his idea of "germ plasm"?

3. What were Mendel's laws on the segregation of traits and on recessive and dominant traits? How did he support these ideas with evidence?

4. What was Galton's argument regarding the inheritance of genius and how did he attempt to prove it?

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2. What was "feeblemindedness"? Why did scientists want to eliminate these people from the population?

3. What was the argument presented for sterilization based on the Jukes family history?

4. How was feeblemindedness portrayed in the Norton pamphlet on âSelective Sterilization in Primer Formâ?

5. How does the Carrie Buck case illustrate the concerns of eugenecists? How does it illustrate social values of the time?

1. What was the Kallikak family study, and how did it differ from the Jukes family study? What were its conclusions?

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1. What were the results of the I.Q. test administered to World War I draftees? How did some people criticize this test and its results?

2. How did increasing research on development and genetics call into question the simple unit-character assumptions of earlier eugenecists?

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4. How was the rise of National Socialism (Nazism) in Germany based on promoting the genetically âhealthyâ and preventing reproduction among the âunhealthyâ? Who was included in the unhealthy category?

5. What was the purpose of the German âhealth courtsâ? How did U.S. sterilization laws serve as models for German sterilization programs?

1. How were Margaret Sangerâs view on birth control similar to and different from eugenics?

2. What were the fears over the âpopulation explosionâ in the 1960s?

3.What similarities are there between the case of the Relf sisters and Madrigal vs. Quilligan?

4. How were sterilizations in the 1960s and 1970s similar to and different from the eugenic sterilizations of the 1920s and 1930s?

5. Why were so many women sterilized in Puerto Rico?

1. What are the basic particles of the atom? What is an isotope?

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3. How did Rutherford explain radioactive decay (Experiment 1)? How are atoms of one element transmuted into another element during radioactive decay?

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3. How did the relationship between the United States and the Soviet Union affect the decision to drop the bomb?

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5. How was the Interim Committee involved in the decision to drop the bomb? Which scientists advised the committee and what did they recommend?

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3. What were the reasons in 1945 for and against dropping the bomb in a surprise attack?

4. With the benefit of hindsight, of more knowledge about the actual state of Japan in 1945, and of further understanding about the effects of the bomb, do you still think that the reasons you suggested in answer to question 3 are valid? Do you think there was any way to have done things differently?

1. How did the United States people first learn of the bombing of Hiroshima? What were they told?

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3. What was the Potsdam ultimatum and how did the Japanese respond? Why did they reject it?

4. What possibilities for a negotiated peace settlement with Japan existed during the summer of 1945? Why were they unsuccessful?

5. When and how did the American public first begin to learn about the effects of the bombings on the people of Hiroshima and Nagasaki?

1. What were some of the reactions of scientists to the bombing of Hiroshima and Nagasaki?

2. What were the major concerns of scientists after the war regarding the development and control of nuclear weapons?

3. How did the events of the Cold War influence the development of the Hydrogen Bomb?

4. What was the recommendation of the General Advisory Committee concerning the H-bomb, and on what reasons was it based?

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The Case of the Aging Surfer

Seth, a thirty-eight year-old white male of Scandinavian descent, has lived his entire life in Southern Florida. He is very concerned with maintaining a "healthy" appearance. Seth is very athletic and especially enjoys surfing. He has been surfing since the age of twelve and he started making surfboards while he was in high school. After obtaining a college degree in marketing Seth decided to start his own business making surfboards and giving surfing lessons for a local resort near his home. During a routine physical examination the physician assistant that Seth sees commented on the presence and appearance of a small growth (approximately 2-cm in diameter) above Seth's right eyebrow. This growth was shiny with a pearly border, a central ulcer and engorged surface blood vessels. The physician assistant was concerned that this might be a tumor and asked Seth a number of questions to aid in the diagnosis. Seth reported that he noticed this growth approximately six months ago but thought nothing about it since he often developed "pimples" when he was working on surfboards because of the heat and dust. Seth noticed that the growth would occasionally bleed, but he thought the bleeding most often occurred when he absently scratched above his eyebrows when he was working. Seth also reported that after bleeding the growth would "crust over" and appear to heal, but not disappear. Seth also thinks the lesion has increased in size, but he can't be certain.

The physician assistant asks Seth to come back in two days to visit with the attending physician and encourages Seth to be sure to use sunscreen whenever possible, especially when he is surfing or teaching surfing classes. Upon returning to see the physician, Seth is told that he probably has a basal cell carcinoma. This, the physician explains, is a cancer that while not benign, rarely metastasizes and grows very slowly. This type of cancer usually occurs in areas that have the greatest exposure to the sun (i.e. the face, head, and neck). While this cancer would probably not metastasize, the physician suggests surgical removal to minimize damage to any underlying tissues and a histological examination of the excised tissue to confirm the diagnosis.

Seth is concerned that if this is indeed cancer he will have to undergo radiation and/or chemotherapy and suffer from both hair loss and nausea like his mother did when she was being treated for breast cancer 10 years ago. The physician assures Seth that these treatments are not required for basal cell carcinoma and explains that this cancer usually remains localized to the specific area of the skin and does not usually spread to other tissues, so radiation and chemotherapy would not be necessary. Seth then asks why it is necessary to remove the tumor if it will not spread and is told that while the tumor does not spread to other body areas it will continue to grow and also invade deeper layers of the skin, such as the dermis, and destroy normal tissues. Seth agrees to the procedure and schedules a follow-up appointment to discuss the results of the biopsy the following week. At the follow-up appointment, Seth is told that the lesion was indeed a basal cell carcinoma. He is told that it will be important for him to try to use both sunscreens, specifically those containing para-aminobenzoic acid or PABA, and protective clothing as much as possible to minimize the effects of the ultraviolet (UV) rays of the sunlight. Seth is also told that while he should not be overly concerned, he should also pay close attention for similar lesions in the future, since a person with a single basal cell carcinoma is likely to develop additional basal cell carcinomas in the future.

http://emedicine.com/derm/topic47.htm

http://www.skincancer.org

The Case of the Aging Surfer:

Define the bold terms in the text.

How are benign and malignant tumors similar and different from each other?

Identify and briefly describe the three most common types of skin cancer and the risk to individuals who have developed each of them.

What are oncogenes and how are they believed to be related to cancer?.

Identify both the primary risk factors that Seth presents with and other risk factors that may or may not relate to Seth's case.

The procedure that Seth experiences is called the Mohs Surgery. What does it involve?

How do chemotherapy and radiation therapy act as treatments for cancer?

8) Explain why tanning booths are actually more dangerous than sunlight exposure in increasing the risk of developing some form of skin cancer.

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2. In the peppered moth (Biston betularia), black individuals may be either homozygous (A1A1) or heterozygous(A1A2), whereas the pale gray moths are homozygous (A2A2). Suppose that in a sample of 250 moths from one locality, 108 are black, and 142 are gray.

3. Retrace the history of primate evolution from early primates to monkeys, apes and hominins. When did some ofthe significant divergences occur (such as between the prosimians and the monkeys or between the chimps and hominins)? What was happening with the continents and the major climatic conditions during these times?What are the major species (including the extinct species) along the human lineage after the split with the chimps and bonobos? Where did many of these events occur on the globe and when?

4. Spencer Wells described his study how the genetic markers in humans are being used to infer the historical geographical distribution of humans and the dispersal of our ancestors. Explain how the genetic markers on our DNA (from blood samples) helps us understand that history. What are the techniques he is using? What is the nature of the evidence? What are the major conclusions about the journey of our ancestors out of Africa?What were the major migrations of humans to all the other continents? Approximately when did each migration occur and what were the major paths? How does the evidence support these conclusions? What Supporting evidence besides the DNA evidence is being used to support these conclusions?

5. Provide an adaptive and a non adaptive hypothesis for the evolutionary loss of useless organs, such as eyes in many cave-dwelling animals. How might these hypotheses be tested?

6. Directional selection is one of the models of natural selection. Describe this type of selection in terms of the frequencies of advantageous alleles over time. What is the trend over time? What is the eventual outcome for this allele as long as no other evolutionary factors intervene? Describe at least one good example of directional selection.

7. Consider the first copy of an allele for insecticide resistance that arises by mutation in a population of insects exposed to an insecticide. Is this mutation an adaptation? If, after some generations, we find that most of the population is resistant, is the resistance an adaptation? If we discover genetic variation for insecticide resistance in a population that has had no experience of insecticides, is that variation an adaptation? If an insect population is polymorphic for two alleles, each of which confers resistance against one of two pesticides that are alternately applied, is that variation an adaptation? Or is each of the two resistance traits an adaptation?Explain your reasoning thoroughly.

8. Suppose that a mutation in a species of annual plant increases allocation to chemical defenses against herbivores, but decreases production of flowers and seeds (i.e., there is an allocation trade-off). What would you have to measure in a field study in order to predict whether or not the frequency of the mutation will increase?

9. In many socially monogamous species of parrots and other birds, both sexes are brilliantly colored or highly ornamented. Is sexual selection likely to be responsible for the coloration and ornaments of both sexes? How can there be sexual selection in pair-bonding species with a 1:1 sex ratio, since every individual presumably obtains a mate? Which of the models of sexual selection described in the book might account for these species characteristics?

10. Kin selection explains why organisms may provide benefits to relatives. Is there a conflict between the principle of kin selection and the evolution of siblicide and abortion?

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12. The concept of a species is fundamental to understanding biology, yet there may not be one definition that fits all âtypesâ of organisms (e.g. animals, plants, fungi, bacteria, slime mold, lichens, etc.). Discuss several of the definitions of a species as presented in class and present your own definition for a species. Compare the strengths and weaknesses of each definition. Ernst Mayr is strong proponent of the biological species concept.How does he justify his position? Do you agree or disagree? If we employ the biological species concept, when did species first exist? What were organisms before then, if not species? What might the consequences of the emergence of species be for processes of adaptation and diversification? Be sure to explain your reasoning thoroughly.

13. The process of speciation ultimately involves the development of reproductive isolation between two related populations of organisms. Describe the various types of both prezygotic and postzygotic reproductive isolation and give an example of each.

14. Respond to the following quote from the character named Mr. Spock in âStar Trekâ:âA truly successful parasite is commensal, living in amity with its host, or even giving it positive advantages, as for instance, the protozoans who live in the digestive system of your termites and digest for them the wood they eat. A parasite that regularly and inevitably kills its host cannot survive long, in the evolutionary sense, unless it multiplies with tremendous rapidity ... it is not pro-survival.âFrom what you have learned in this course, do you agree or disagree with Spock? How can you apply your reasoning to the relative âfitnessâ of HIV which causes AIDS, the Ebola virus which causes hemorrhagic fever,fleas which suck blood from dogs, or the prokaryotic ancestors of mitochondria and chloroplasts?

15. In many species of birds and mammals, clutch size is larger in populations at high latitudes than in population sat low latitudes. Species of lizards and snakes at high latitudes often have smaller clutches, however, and are more frequently viviparous (bear live young rather than laying eggs), than low-latitude species. What selective factors might be responsible for these patterns? Explain your reasoning.

16. The popular media often presents evolution as being a predictable process with a definite goal. For instance, in one âStar Trek: Voyagerâ episode, the captain instructs the shipâs computer to extrapolate the âprobable courseâ of evolution of hadrosaurs (a bipedal dinosaur), if hadrosaurs had been removed from Earth before the Cretaceous-Tertiary (K-T) Extinction and allowed to evolve on another planet. What information about the hadrosaursâ new environment would have been useful in developing the best possible prediction? Given what you know on genetic drift and selective agents, is it possible to accurately predict the long-term course of evolution?

17. Young children often develop strong food preferences that sometimes seem bizarre to their parents --- such as wanting to eat only a certain food prepared in a familiar way, or being reluctant to each new foods or foods with strong or bitter tastes (like coffee and some vegetables). Develop an evolutionary explanation for such preferences. What evidence would you gather to investigate your hypothesis and rule out alternative explanations?

18. Many organisms, such as mammals, only reproduce by sexual means. Other organisms are exclusively asexual,such as many of the bacteria and fungi. And still others have ways of propagating by both sexual and asexualmeans. Discuss the relative advantages and disadvantages of each mode of reproduction. Why arenât all organisms sexual critters? Why are many asexual organisms still very successful as evidenced by the pure abundance and diversity? What is the adaptive significance of having different genders (e.g. male and female)?In other words, why sex?

19. How might differential expression and regulation by Hox genes contribute to mosaic evolution in which different segments of an animal body plan evolve different morphology?

20. Development of a morphological structure involves many different types of gene products, including transcription factors, signaling proteins, and âeffectorâ genes such as enzymes. When a morphological change occurs in a single mutational step, which of these types might be more or less likely to be involved? Within a gene, would such single-step events be more likely to involve coding or non-coding sequences, and what characteristics of the geneâs function might affect this likelihood?

21. Since 2001, the complete DNA sequences of the genomes of many people have been determined. If humans,along with other forms of life, have evolved from a common ancestor, what evidence of this would be expected in the human genome? In what ways might the history and processes of evolution help us interpret and make sense of the human genome sequence data?

22. Paleontologists and some biologists commonly infer function, and even behavior, from anatomical details.Skeletal features, for example, are often used to infer that an extinct mammal (such as an early hominid) was highly, somewhat, or not at all arboreal. This inference assumes a good fit of form to function (i.e., optimal form). Can this assumption be justified?

23. Stephen Jay Gould (1989) and others have argued that the evolution of self-conscious, intelligent species (i.e.humans) was historically contingent: it would not have occurred had any of a great many historical events been different. The philosopher Daniel Dennett (1995) and others have disagreed, arguing that convergent evolution is so common that if humans had not evolved, some other lineage would probably have given rise to a species with similar mental abilities. What do you think, and why? If Gouldâs position is right, what are its philosophical implications, if any?

24. Explain how Intelligent Design was determined as a religious view rather than a scientific view in the court casein Dover, PA. Should a scientific explanation of evolution be included in a science curriculum in K-12 schools?How is science and religion different in how they seek answers to questions? How is term "theory" used differently in science than in everyday English use? What is biological evolution? What evidence is used to support the scientific explanation of evolution? Is it possible to accept scientific explanations without rejecting religious faith?

25. Discuss how a creationist versus an evolutionary biologist might explain some human characteristics and the implications of their differences. Sample characteristics: eyes; wisdom teeth; individually unique friction ridges(fingerprints); five digits rather than some other number; susceptibility to infections; fever when infected;variation in sexual orientation; limited life span.