Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[Q]: Carbon is one of the most common elements found in living organisms. Chains of carbon molecules form the backbones of many organic molecules, such as carbohydrates, proteins, and lipids. Carbon is constantly cycling between living organisms and the atmosphere ( Figure 1.1). The cycling of carbon occurs through the carbon cycle. Living organisms cannot make their own carbon, so how is carbon incorporated into living organisms? In the atmosphere, carbon is in the form of carbon dioxide gas (CO2 ). Recall that plants and other producers capture the carbon dioxide and convert it to glucose (C6 H12 O6 ) through the process of photosynthesis. Then as animals eat plants or other animals, they gain the carbon from those organisms. The chemical equation of photosynthesis is 6CO2 + 6H2 O C6 H12 O6 + 6O2 . How does this carbon in living things end up back in the atmosphere? Remember that we breathe out carbon dioxide. This carbon dioxide is generated through the process of cellular respiration, which has the reverse chemical reaction as photosynthesis. That means when our cells burn food (glucose) for energy, carbon dioxide is released. We, like all animals, exhale this carbon dioxide and return it back to the atmosphere. Also, carbon is released to the atmosphere as an organism dies and decomposes. Cellular respiration and photosynthesis can be described as a cycle, as one uses carbon dioxide (and water) and makes oxygen (and glucose), and the other uses oxygen (and glucose) and makes carbon dioxide (and water). The carbon cycle. The cycling of car- bon dioxide in photosynthesis and cellular respiration are main components of the carbon cycle. Carbon is also returned to the atmosphere by the burning of organic matter (combustion) and fossil fuels and decomposition of organic matter. Millions of years ago, there were so many dead plants and animals that they could not completely decompose before they were buried. They were covered over by soil or sand, tar or ice. These dead plants and animals are organic matter made out of cells full of carbon-containing organic compounds (carbohydrates, lipids, proteins and nucleic acids). What happened to all this carbon? When organic matter is under pressure for millions of years, it forms fossil fuels. Fossil fuels are coal, oil, and natural gas. When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure 1.2). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas, since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earths temperature, known as global warming or global climate change.
[A]: when organisms die, what process returns their carbon back into the atmosphere?

[Q]: One day, a slave owner entered a local store and threatened a young boy who was his slave. At first, the slave refused to move and ran for the door. The slave owner reached for a heavy weight. He threw it at his slave. Instead, it hit Harriet on the head. Harriet almost died. For the rest of her life, she carried the mark of a deep wound on her head. Miser Brodas felt he never needed Harriet. He decided to sell her. Harriet thought of a way to prevent this. Each time she was shown to someone who might buy her, she acted as if she were falling asleep. After a while, Mister Brodas gave up the hope of selling Harriet. He sent her back to the fields. At 24 she married a free black man, John Tubman. By then, Harriet was sure she should escape. In 1849, Mister Brodas died. His slaves probably would be sold to further South. John Tubman tried to make Harriet forget about running away. Harriet decided she must end her marriage and that she needed to tell her family that she was leaving. Harriet escaped for Pennsylvania where slavery was banned there. Once she hid under hay that had been cut from the fields. Another time, she wore men's clothing. Finally, she arrived in Pennsylvania. Now that Harriet was free, she didn't forget other slaves in Maryland. During the next ten years, she freed her parents and other family members. She traveled back and forth eighteen times, helping about 300 slaves escape. She became an expert at hiding from slave hunters. At one time, anyone finding Harriet was promised 40,000dollars for catching her--dead or alive. The people she helped called her Moses. She had rescued them from slavery just as the biblical Moses rescued the Jews. After the Civil War began, Harriet started to spy for the North. She also served as a nurse. After four years of bloody fighting, the North won the war. Abraham Lincoln freed the slaves in 1863. There was no longer any need for Harriet to be Moses.
[A]: We know from the passage that Harriet was Mister Brodas' .

[Q]: Kell antigens are encoded by the KEL gene on the long arm of chromosome 7. Kx antigen is encoded by the XK gene on the short arm of the X chromosome. Kell and Kx proteins in the red cell membrane are covalently linked by a disulphide bond. The McLeod phenotype is characterized by weakened expression of antigens in the Kell blood group system, absence of Km and Kx antigens, and acanthocytosis. It has an X-linked mode of inheritance with transmission through carrier females. Some males with the McLeod syndrome also have chronic granulomatous disease (CGD). It is generally believed that patients with non-CGD McLeod may develop anti-Km but not anti-Kx, but that those with CGD McLeod can develop both anti-Km and anti-Kx. We present serological data, DNA genotyping and gene sequencing, monocyte monolayer assay and neutrophil oxidative burst test from a patient with the McLeod phenotype without clinical evidence of CGD. We report here the second example of a patient with non-CGD McLeod who developed anti-Kx in addition to anti-Km. Sequencing of our patient's XK gene confirmed the presence of a mutation resulting in a premature stop codon and lack of Kx protein in the red cell membrane, which is consistent with the diagnosis of McLeod syndrome. Neutrophil oxidative burst test was normal, indicating that our patient did not have CGD. The challenge of providing 10 compatible blood units for multiple surgeries was met. The second case of a rare entity, a patient with non-CGD McLeod who developed anti-Kx and anti-Km, was managed successfully with a combination of autologous donations and procurement of compatible units from national and international sources.
[A]:
Mutation of which gene is associated with McLeod syndrome?