Primary Source

Imagine you are in a fast-food restaurant where a lady tells you that she had heard there was a gene for liking or hating the taste of cilantro. You looked on the Internet to investigate this statement, and although you found similar comments on reputable websites, you are yet to find any scientific studies supporting this claim.

• Should you be skeptical about the scientific merit of this claim after browsing the Internet? Why?
• Do you think there are times when scientifically-sound research is not accepted for publication? Why?
• What should you do to continue this investigation?
• Using the University Online Library, find two peer-reviewed articles discussing genetics and food preference. Using the skills you learned from this week’s lectures, summarize each of them.
• What is a primary source for any research study? Why is it important to read the primary source?
• Why do most students settle for reading secondhand or thirdhand accounts of research studies instead of reading the primary source?
• When might you have to depend on a secondary source of information? Are third hand accounts of research studies reliable? Why?

Question 2

• Explain the experimental design used by Mendel in both a monohybrid and a dihybrid cross to

support his two principles?

• Explain how complete dominance, co-dominance, and incomplete dominance differs or agrees

with what Mendel showed from his experiments?

• Explain how or why multiple alleles, pleitrophy, and penetrance expression in a phenotype do

not fit the Mendelian model?

• Explain how or why polygenic and epistasis expression in a phenotype do not fit the

Mendelian model?

• ) Explain why Thomas Morgan’s work with fruit flies showed the potential variation in

populations?

Explain how Morgan’s lab was able to show the existence of sex-linkage of certain traits?

• Explain how ultrasound, amniocentesis, chorionic villi sampling, fetal tissue sampling, or

pedigree information can be used to detect genetic anomalies in a fetus?