Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

[Q]: Context: DNA and RNA are nucleic acids. DNA stores genetic information. RNA helps build proteins. Proteins, in turn, determine the structure and function of all your cells. Proteins consist of chains of amino acids. A proteins structure and function depends on the sequence of its amino acids. Instructions for this sequence are encoded in DNA. In eukaryotic cells, chromosomes are contained within the nucleus. But proteins are made in the cytoplasm at structures called ribosomes. How do the instructions in DNA reach the ribosomes in the cytoplasm? RNA is needed for this task. RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. How is the information for making proteins encoded in DNA? The answer is the genetic code. The genetic code is based on the sequence of nitrogen bases in DNA. The four bases make up the letters of the code. Groups of three bases each make up code words. These three-letter code words are called codons. Each codon stands for one amino acid or else for a start or stop signal. There are 20 amino acids that make up proteins. With three bases per codon, there are 64 possible codons. This is more than enough to code for the 20 amino acids plus start and stop signals. You can see how to translate the genetic code in Figure 5.17. Start at the center of the chart for the first base of each three-base codon. Then work your way out from the center for the second and third bases. Find the codon AUG in Figure 5.17. It codes for the amino acid methionine. It also codes for the start signal. After an AUG start codon, the next three letters are read as the second codon. The next three letters after that are read as the third codon, and so on. You can see how this works in Figure 5.18. The figure shows the bases in a molecule The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. The process in which proteins are made is called protein synthesis. It occurs in two main steps. The steps are transcription and translation. Watch this video for a good introduction to both steps of protein synthesis: [Link] MEDIA Click image to the left or use the URL below. URL: Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as 
 Question: _____double-stranded nucleic acid
[A]: dna


[Q]: Context: The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. Mercury is named for the Roman messenger god, who could run extremely quickly, just as the planet moves very quickly in its orbit around the Sun. A year on Mercury the length of time it takes to orbit the Sun is just 88 Earth days. Despite its very short years, Mercury has very long days. A day is defined as the time it takes a planet to turn on its axis. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 57 Earth days long. In other words, on Mercury, a year is only a Mercury day and a half long! Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. Figure 1.3 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Its relatively large, liquid core, made mostly of melted iron, takes up about 42% of the planets volume. 
 Question: the core of mercury is made mostly of melted
[A]: iron


[Q]: Context: Take Shelter premiered in January 2011 at the Sundance Film Festival, and Sony Pictures Classics acquired rights to distribute the film in North America, Latin America, Australia, and New Zealand. 
 Question: What was the production company for Take Shelter?
[A]:
sony pictures classics