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)*. (* 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. In humans, there is a gene that controls formation of hemoglobin, the protein in the red blood cells which carries oxygen to the body tissue. A photo, taken by Dr. Dihybrid Cross: If the man is both Rr and Tt (How do we know that?) Multiple Alleles and Codominance:
Genetic Diseases May Receive Help from Modified HIV Virus First Posted: Jul 12, 2013 12:11 AM EDT Scientists may have just identified a potential drug to block AIDS. They've found the precise chain of molecular events in the human body that drives the death of most of the immune system's CD4 T cells as an HIV infection leads to AIDS. (Photo : Reuters) Recent research shows promising results for children with hereditary diseases like metachromatic leukodystrophy and Wiskott Aldrich syndrome who undergo gene therapy vectors derived from the HIV virus. Like Us on Facebook "Three years after the start of the clinical trial, the results obtained from the first six patients are very encouraging: the therapy is not only safe, but also effective and able to change the clinical history of these severe diseases," lead researcher Luigi Naldini said in a news release. Researchers looked to the therapy in order to determine if it could help alleviate problems affected by the disease. More information regarding the study can be found in the journal Science.
Web Lab Directory Siamesiska tvillingar Genetic Disorders Harmonizing a Broken Heart: Stem Cells Keep Cardiac Beat in Synchrony First Posted: Sep 04, 2013 03:00 PM EDT Stem cell therapy used to regenerate injured tissue in the heart also restores synchronous pumping, new research shows, and could thus be used to make pacing devices redundant. Like Us on Facebook The team behind the study proposes a novel strategy of “biological resynchronization” in which stem cells repair heart muscle damage to reestablish correct cardiac motion, replacing pacing devices, Heart attacks limit local oxygen, which can kill areas of cardiac tissue — called ‘infarcted’ areas — and also leave scarring. Current therapies use pacing devices, but these require healthy tissue for optimal outcome, meaning a third of patients do not respond well to this treatment. Professor Andre Terzic, who led the study, explains the importance of this potential new therapy: “Heart chambers must beat in synchrony to ensure proper pumping performance. (Photo : Wiley)Regeneration of damaged heart tissue synchronizes its motion. Reference:
Chpt 3 One Wrong Letter 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. What he got from Martin Fugate was dark blue skin. Doctors were so astonished by the color of Benjy Stacy's skin that they raced him by ambulance from the maternity ward in the hospital near Hazard to a medical clinic in . A transfusion was being prepared when Benjy's grandmother spoke up. "My grandmother Luna on my dad's side was a blue Fugate. Benjy lost his blue tint within a few weeks, and now he is about as normal looking a seven-year-old boy as you could hope to find. Cawein is no stranger to eccentricities of the body.
Is the Will to Work Out Genetically Determined? What a 94-year-old athlete and an obsessive albino mouse can teach us about habits. To a certain kind of sports fan—the sort with a Ph.D. in physiology—Olga Kotelko is just about the most interesting athlete in the world. A track and field amateur from Vancouver, Canada, Kotelko has no peer when it comes to the javelin, the long jump, and the 100-meter dash (to name just a few of the 11 events she has competed in avidly for 18 years). And that’s only partly because peers in her age bracket tend overwhelmingly to avoid athletic throwing and jumping events. Kotelko, you see, is 94 years old. Scientists want to know what’s different about Olga Kotelko. Olga’s DNA instead may help her out in a subtler way. If scientists crack the genetic code for intrinsic motivation to exercise, then its biochemical signature can, in theory, be synthesized. Dean is the product of a long-running study of voluntary exercise. And therein lies another weird direction for the research to go.
Spermadonator hade ärftlig sjukdom Spermabanken, Nordisk Cryobank, fick i juni 2009 veta att ett av donatorns barn fötts med sjukdomen, neurofibromatos typ 1. Men banken bröt mot reglerna och lät bli att informera om att deras donator hade en allvarlig sjukdom. Det dröjde sex månader innan informationen gick ut. Enligt danska myndigheter har säd från donatorn använts vid 14 kliniker. Kliniker ska informeras Peter Bower, chef för Nordisk Cryobank, säger att läkarna till och börja med inte trodde att sjukdomen hade något med donatorn att göra. Enligt reglerna ska alla kliniker som köpt säden omgående informeras när sådan sjukdom upptäcks och säden ska därefter inte användas. Sjukdomen kan ge symtom från hud, ögon, skelett och nervsystem. Behov att ändra lag Spermaskandalen i Danmark visar på behovet av att ändra den svenska lagstiftningen. -Det brister i återkopplingen, både mellan kliniken och kvinnorna och mellan kliniken och spermabanken. Mindre risk i Sverige -Det finns flera saker som skiljer de båda länderna åt.
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. "The immunity was transferred in the form of small viral-silencing agents called viRNAs, working independently of the organism's genome." In an early theory of evolution, Jean Baptiste Larmarck (1744-1829) proposed that species evolve when individuals adapt to their environment and transmit those acquired traits to their offspring. Dr.
The search for a genetic killer The medical examiner for the Sandy Hook shooting has requested a genetic analysis of killer Adam Lanza. Following this, a powerful editorial in the science magazine Nature has condemned the move suggesting it is “misguided and could lead to dangerous stigmatization.” But the request to analyse the DNA of Lanza is just the latest in a long line of attempts to account for the behaviour of individual killers in terms of genetics. Perhaps the first attempt was for a case that bears more than a surface resemblance to the Sandy Hook shooting. In 1998, a 15-year-old high school student called Kip Kinkel killed both of his parents before driving to school and shooting 24 students, one of whom died. In his trial a child psychiatrist argued that Kinkel had “genetic loading” that made him susceptible to mental illness and violence. His appeal also relied upon this angle. Perhaps for the first in decades, an appeal to genetics was used in an attempt to explain the killer’s behaviour.
Genetically Modified Foods Can you think of some possible risks of growing plants that contain genes from other organisms? Let's examine our earlier examples: the beetle-resistant tomato, the vaccination banana, and the saltwater rice plant. We've already covered the potential advantages of these plants, but what are the concerns? Cross-breeding with wild populations. For all of these examples, a primary concern is preventing genetically modified versions from mixing with the naturally existing populations of plants from which they're derived. Plants rely on the transfer of pollen, via insects or the air, to breed and produce offspring, and it's difficult to control how they cross-breed in the wild. In most cases, it's not yet clear how introduction of the non-native gene would affect wild populations. Toxicity or allergic reactions. When farmers start growing genetically modified crops, they stop growing the old varieties.