what is a recessive trait that has a benefit for the organism other than sickle cell?
152924
Sickle cell trait/disease is an example of heterozygote advantage, in that homozygous recessive individuals (people with two sickle cell genes) have sickle cell anemia, which is bad, but people who are heterozygous for the gene (one normal and one mutant) have sickle cell trait, which provides resistance against malaria, which is good.\n\nAnother example of heterozygote advantage is cystic fibrosis.  As you probably know, cystic fibrosis is a fairly nasty recessive genetic disorder.  People with the recessive condition typically have a life expectancy of only a few years.  However, the heterozygous condition provides some defense against diseases that invovle loss of body fluid (typically diarrhea).  Cystic fibrosis is relatively common among people of European descent because carriers of the allele were more likely to survive cholera, which was a problem throughout European history.\n\nThere is also some evidence to suggest that the heterozygous carriers of the Tay-Sachs allele may have increased resistance to tuberculosis, although this has yet to be confirmed.
719142
It's a genetic variation like eye colour or skin tone.  \nSome specific diseases do not affect certain blood types and thus it seems like differnt blood types have evolved to combat these diseases.\n\n(I am A positive by the way)
188037
get different genetics
212609
Recessive. Because it is a loss of function mutation. Your body does not produce enough lactase, If it can make enough with the heterozygous alleles then it passes a threshold level enough to make you not lactose intollerant.  I mean this is a simplified model, usually this is due to several genes, you might want to look at something called genetic complemenation. \nBTW... the guy on the top is a moron. The Lactase is not dependant on the E. Coli, otherwise this wouldn't be a heritable trait.
569080
It's an inherited disease. Both parents give their child the sickle cell allele.\nSickle cell anemia is caused by an abnormal type of hemoglobin called hemoglobin S. Hemoglobin is a protein inside red blood cells that carries oxygen. Hemoglobin S, however, reduces the amount of oxygen inside the cells, distoring their shape. The fragile, sickle-shaped cells deliver less oxygen to the body's tissues, and can break into pieces that disrupt blood flow.
622289
Sickle cell anemia is a hereditary disorder that mostly affects people of African ancestry, but also occurs in other ethnic groups, including people who are of Mediterranean and Middle Eastern descent. More than 70,000 Americans have sickle cell anemia. And about 2 million Americans - and one in 12 African Americans - have sickle cell trait (this means they carry one gene for the disease, but do not have the disease itself). \n\nSickle cell anemia occurs when a person inherits two abnormal genes (one from each parent) that cause their red blood cells to change shape. Instead of being flexible and round, these cells are more rigid and curved in the shape of the farm tool known as a sickle - that's where the disease gets its name. The shape is similar to a crescent moon.\n\nWhat Is Sickle Cell Anemia? \nSickle cell anemia is a blood disorder that affects hemoglobin (pronounced: hee-muh-glow-bin), a protein found in red blood cells that helps carry oxygen throughout the body. \n\nRed blood cells with normal hemoglobin (HbA) move easily through the bloodstream, delivering oxygen to all of the cells of the body. Normal red blood cells are shaped like doughnuts with the centers partially scooped out and are soft and flexible. \n\nSickle cell anemia occurs when an abnormal form of hemoglobin (HbS) is produced. HbS molecules tend to clump together, making red blood cells sticky, stiff, and more fragile, and causing them to form into a curved, sickle shape. Red blood cells containing HbS can go back and forth between being shaped normally and being sickle shaped until they eventually become sickle shaped permanently. Instead of moving through the bloodstream easily, these sickle cells can clog blood vessels and deprive the body's tissues and organs of the oxygen they need to stay healthy. \n\nUnlike normal red blood cells that last about 4 months in the bloodstream, fragile sickle cells break down after only about 10 to 20 days, which usually causes anemia. Anemia (pronounced: uh-nee-mee-uh) is what happens when the body's number of red blood cells (or amount of hemoglobin) falls below normal. People who are anemic often feel weak and tire more easily.\n\nPeople with sickle cell anemia can also experience complications from blood circulation and infection-fighting problems. These include a higher risk of certain infections and stroke as well as a condition called acute chest syndrome, which is caused by infection or trapped red blood cells in the lungs.\n\nSickle cell anemia is not contagious, so you can't catch it from someone else or pass it to another person like a cold or other infection. People with sickle cell anemia have inherited two sickle cell genes, one from each parent. A child who has inherited the sickle cell gene from only one parent will not develop the disease, but will have sickle cell trait. People who have sickle cell trait don't have sickle cell anemia or symptoms of the disease, but they can pass the sickle cell gene to their own children.\n\nBecause people with sickle cell trait don't have the disease, they may never discover that they carry the gene. That's why it's recommended that teens who are unsure of their sickle cell status ask their doctors about testing. The National Institutes of Health recommends that all newborns be screened for sickle cell disease, and testing at birth is now required in almost every state. This helps infants with sickle cell anemia get the care and treatment they need right away.
246520
You will learn a lot from the wikipedia article on this, http://en.wikipedia.org/wiki/Sickle_Cell_Anemia
806888
non-mendelian inheritance can be seen in disorders that are polygenic or mutations that have varying expressivity.
623305
Sickle-cell anemia is encountered almost exclusively in people of African descent, although there are always exceptions.  The reason sickle-cell anemia is so common (compared to other genetic disorders) in certain populations is that carriers of the gene (i.e. people who have only one copy of it) have slightly oddly shaped red blood cells, which don't cause any problems for them but aren't so great for the parasite that causes malaria.  Since carriers are resistant to malaria, the gene that causes sickle-cell is extremely common only within populations from regions where malaria is endemic.  Since malaria is quite prevalent in many regions of Africa, sickle-cell is also prevalent in people whose ancestry traces back to those regions.  Sickle-cell can pop up anywhere, in any population through random mutation (if I remember correctly, it's a single nucleotide mutation), but without malaria to give heterozygous individuals (i.e. carriers) an advantage, it does not become nearly as common as it did in African populations.
110246
Sickle cell disease is much more common in certain ethnic groups, but not unheard of in all. Someone who inherits hemoglobin S from one parent and normal hemoglobin (A) from the other parent will have sickle cell trait. (Hemo. S being the one that reduces the oxygen in blood cells)
113778
People who are heterozygous (carriers) for sickle cell anemia have resistance to malaria. Carriers can have what is called "sickle cell trait" because they may show only slight symptoms during severe exertion. Two carriers have a 25% chance of having a child with sickle cell anemia.  These children have an increased death rate, even in their twenties during child rearing years.  Since areas of Africa with the highest malarial rates show the highest sickle cell rates, the trait seems to be selected for evolutionarily.
9126
Sickle cell anemia pre-dominately occurs in African-Americans; yet, also occurs in people of Mediterranean and Middle Eastern descent.  I was reading on a website that said 1 in 12 African -Americans carry the recessive gene that causes the sickle cell disorder.  Thankfully, stem cell researchers have and are currently developing more treatments & cures for the disorder.
255525
Sickle Cell Anemia in the US\n- 72,000 cases in America(CBCF Health Organisation, 2004)\n- Most cases occur in those with African ancestors in America (CBCF Health Organisation, 2004)\n- 2 million people carry the sickle cell genetic trait in America (CBCF Health Organisation, 2004)\n- 1 in 12 African Americans carry the sickle cell trait in America (CBCF Health Organisation, 2004)\n- About 91,000 people with sickle cell anemia ("Orphan Products: Hope for People With Rare Diseases", By Carol Rados, FDA Consumer magazine, November-December 2003 Issue) \n\n\nA genetic mutation of hemoglobin called HbS conveys sickle cell anemia. HbS carriers would be selected for because it gives some resistance to malaria. Their red blood cells, containing some abnormal hemoglobin, tend to sickle when they are infected by the malaria parasite. Those infected cells flow through the spleen, which culls them out because of their sickle shape -- and the parasite is eliminated along with them.\n\nSo in malaria infested areas of Africa Sickle Cell anemia is a very real protection against one of the major killers. While children with HbS from both parents die, those with only one set of HbS are somewhat protected against malaria - a valuable enough trait to keep it alive in a population.
228441
There is not a recessive (or for that matter dominant) gene for diabetes. \n\nType 1 is inherited, but only as a vulnerability for some HLA types. These are the 'self' proteins which distinguish you from all others (save your identical twin). An infection seems to be the most common way to get the immune system confused enough to also attack the beta cells. There may be an advantage in having one of the 'diabetes tendency' HLA setups, but I'm aware of none. It may be, as some speculate about Black Death surviors and their descendants, that they are less susceptible to some diseases. This is quite hard to study and tese out any benefit. If present, it's hardly as easily distinguished as was the sicle cell trait. \n\nAs for Type 2, there is even more ineritabiliyt, and not one gene (recessive or not). Type 2 clearly can develop from any of several issues, all connected with insulin resistance of one degree or another. Again, there may be an advantage to having genes leading to Type 2 (usually with an environmental push -- obesity, age, stress, some medications,  ...), but it is speculative and there is little evidence of it. Again studies to find such an advantage will be long, awkward adn expensive. Possibly worth doing, but businesse must limit large expenditures to something they can have some reason will produce revenue. Long term studies o fthis sort are hard to justify on that basis.
715961
If this is a single-gene trait (which your problem assumes) for which the disease is the recessive trait, and everyone else is healthy, both parents must be Cc, since that is the only way they could possibly not have the trait but be able to pass it on.
216865
Some traits are determined by the combined effect of more than one pair of genes.  These are referred to as polygenic, or continuous, traits.  An example of this is human stature.  The combined size of all of the body parts from head to foot determines the height of an individual.  There is an additive effect.  The sizes of all of these body parts are, in turn, determined by numerous genes.   Human skin, hair, and eye color are also polygenic traits because they are influenced by more than one allele at different loci.  The result is the perception of continuous gradation in the expression of these traits.\n\nWhoops!  I didn't realize I used the same source as the answer above!  :o)  Sorry.
882438
a lot of diseases are recessive, meaning you have to have 2 of the diseased gene before the disease shows. in the normal population a girl and a guy wouldn't have a large chance of having 2 recessive genes and give their child the disease, but if the girl and guy are related the chance of them both having a recessive diseased gene are much higher. therefore their chance of having a diseased child is much greater.