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Genetics Practice Problems

Genetics Practice Problems
Genetics Practice Problems You may type in your own answers, then check to see if you were right. If you’re totally stumped, you can tell the computer to show you the answer to a particular question. Monohybrid Cross: In humans, brown eyes (B) are dominant over blue (b)*. A brown-eyed man marries a blue-eyed woman and they have three children, two of whom are brown-eyed and one of whom is blue-eyed. (* Actually, the situation is complicated by the fact that there is more than one gene involved in eye color, but for this example, we’ll consider only this one gene.) Testcross: In dogs, there is an hereditary deafness caused by a recessive gene, “d.” Incomplete Dominance: Note: at least one textbook I’ve seen also uses this as an example of pleiotropy (one gene – multiple effects), though to my mind, the malaria part of this is not a direct “effect” of the gene. A photo, taken by Dr. Dihybrid Cross: If the man is both Rr and Tt (How do we know that?) Multiple Alleles and Codominance: Ms. Epistasis:

http://biology.clc.uc.edu/courses/bio105/geneprob.htm

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Does Sunscreen Protect my DNA? In this laboratory experiment students explore how effectively different sunscreens protect yeast cells from damage caused by ultraviolet (UV) radiation. DNA contains the instructions for proper cell function; changes to DNA can cause cancer; skin cancer can be caused by exposure to UV radiation, which comes from the sun; and the meaning of SPF ratings on sunscreens. Class Time: Two 45 minute class times Prep Time: 1-2 hours Does Sunscreen Protect my DNA? Student Version Does Sunscreen Protect my DNA?

Kentucky Blues The story of an Appalachian malady, an inquisitive doctor, and a paradoxical cure. by Cathy Trost ©Science 82, November, 1982 Six generations after a French orphan named Martin Fugate settled on the banks of eastern 's Troublesome Creek with his redheaded American bride, his great-great-great great grandson was born in a modern hospital not far from where the creek still runs. The boy inherited his father's lankiness and his mother's slightly nasal way of speaking. Color Blind Chart Pattern baldness in men is a sex-influenced trait. It is not an X-linked trait like color blindness and hemophilia. Baldness is an autosomal trait and is apparently influenced by sex hormones after people reach 30 years of age or older. This condition is inherited as a simple Mendelian trait, although the biochemical mechanism is complex. There are other causes for baldness not related to simple Mendelian genetics, such as illness, severe stress, and pulling one's hair out by the roots. In men the gene is dominant, while in women it is recessive.

Apparently This Matters: New baby zonkey New baby zonkey Telegraph hangs out with his zebra mom at the Taigan zoo park in southern Crimea. Strange. No sign of his deadbeat donkey dad. What an ass. Acquired traits can be inherited via small RNAs Columbia University Medical Center (CUMC) researchers have found the first direct evidence that an acquired trait can be inherited without any DNA involvement. The findings suggest that Lamarck, whose theory of evolution was eclipsed by Darwin's, may not have been entirely wrong. The study is slated to appear in the Dec. 9 issue of Cell. "In our study, roundworms that developed resistance to a virus were able to pass along that immunity to their progeny for many consecutive generations," reported lead author Oded Rechavi, PhD, associate research scientist in biochemistry and molecular biophysics at CUMC.

Quick Trait Calculator - Genetic Heredity Calculator Note These calculators use simplified models to calculate traits and their certainty is far from 100% due to the fact that human genetics is far more complex than a simple mendelian dominant/recessive model. Personal Report and Heredity Report give better results, providing that you had your genome sequenced by a commercial personal genomics companies like 23andMe, deCODEMe or Family Tree DNA. In any case, these reports do not substitute for clinical tests, genetic counseling or paternity/maternity tests.

Using Karyotypes To Diagnose Genetic Disorders Sometimes chromosomes are incorrectly distributed into the egg or sperm cells during meiosis. When this happens, one cell may get two copies of a chromosome, while another cell gets none. Incorrect distribution of chromosomes is called nondisjunction. If a sperm or egg cell with too many or too few chromosomes participates in fertilization, it will produce a zygote with too many or too few chromosomes. A zygote with 3 copies of a chromosome is said to have trisomy (pronounced TRY-so-mi). 100 Years of Breed “Improvement” For the sake of honest disclosure, I will admit to owning “purebreds” (the ‘pureness’ of purebreeds is a discussion for another time) but I also have mutts. All the dogs I’ve had since childhood had a few things in common, they were friendly, prey driven, ball-crazy, intense, motivated, athletic (crazy dogs are easier to train) and none had intentionally bred defects. I would never buy/adopt a dog whose breed characteristics exacted a health burden.(Asher 2009). That just incentivizes people to breed more of these intentionally unhealthy animals.

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