Question: Given the background: One of the most common chromosome abnormalities is Down syndrome , due to nondisjunction of chromosome 21 resulting in an extra complete chromosome 21, or part of chromosome 21 ( Figure below ). Down syndrome is the only autosomal trisomy where an affected individual may survive to adulthood. Individuals with Down syndrome often have some degree of mental retardation, some impairment of physical growth, and a specific facial appearance. With proper assistance, individuals with Down syndrome can become successful, contributing members of society. The incidence of Down syndrome increases with maternal age. The risk of having a child with Down syndrome is significantly higher among women age 35 and older. and the situation: Norm and Ian were two brothers. Norm was a totally normal individual, while Ian had Down syndrome. Their parents loved them both equally. Answer the following question: Which brother had no impairment of physical growth?
Answer: Norm

Question: Given the background: Before iodized salt was developed, some people experienced a number of developmental difficulties, including problems with thyroid gland function and mental retardation. In the 1920s, we learned that these conditions could usually be treated easily with the addition of iodide anion to the diet. One easy way to increase iodide intake was to add the anion to table salt. This simple step greatly enhanced health and development. Large amounts of iodide ion are also found in seaweed such as kelp (see picture above) and saltwater fish. and the situation: People from two villages ate lots of salt. People from Salt village used regular salt, while people from Sand village people used iodized salt in their diets, after talking to specialists. Answer the following question: Which village had fewer people experience thyroid gland problems?
Answer: Sand

Question: Given the background: It mutates DNA. The Chernobyl disaster was a nuclear accident that occurred on April 26, 1986. It is considered the worst nuclear power plant accident in history. A Russian publication concludes that 985,000 excess cancers occurred between 1986 and 2004 as a result of radioactive contamination. The 2011 report of the European Committee on Radiation Risk calculates a total of 1.4 million excess cancers occurred as a result of this contamination. and the situation: A Power plant meltdown near the town of Jeskai causes a large amount of radiation to leak into the surrounding area. While some evacuated many people just assumed the power plant should be far enough away to not really affect them. . Answer the following question: Will the citizens that evacuated Jeskai have an increased or decreased chance of getting cancer?
Answer:
decreased