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

[EX Q]: Selenocysteine, a selenium-containing analog of cysteine, is found in the prokaryotic and eukaryotic kingdoms in active sites of enzymes involved in oxidation-reduction reactions. Its biosynthesis and cotranslational insertion into selenoproteins is performed by an outstanding mechanism, implying the participation of several gene products. The tRNA(Sec) is one of these. In eukaryotes, its transcription mode by RNA polymerase III differs from that of classical tRNA genes, both at the level of the promoter elements and transcription factors involved. In addition, enhanced transcription is afforded by a newly characterized zinc finger activator. Not only transcription of the gene, but also the tRNA(Sec) itself is atypical since its 2D and 3D structures exhibit features which set it apart from classical tRNAs. Decoding of eukaryotic selenocysteine UGA codons requires a stem-loop structure in the 3'UTR of mRNAs, the selenocysteine insertion sequence (SECIS) element. Structure probing and sequence comparisons led us to propose a 2D structure model for the SECIS element, containing a novel RNA motif composed of four consecutive non-Watson-Crick base-pairs. A 3D model, rationalizing the accessibility data, was elaborated by computer modeling. It yields indicative or suggestive evidence for the role that could play some conserved residues and/or structural features in SECIS function. These might act as signals for interaction with SBP, the SECIS binding protein that we have characterized.
[EX A]: What is the name of the stem loop present in the 3' end of genes encoding for selenoproteins?

[EX Q]: Have you ever been to the ocean or eaten seafood? If you have, then youve probably encountered members of Phylum Mollusca. In addition to snails, mollusks include squids, slugs, scallops, and clams. You can see a clam in Figure 12.15. There are more than 100,000 known species of mollusks. Some mollusks are nearly microscopic. The largest mollusk, the colossal squid, may be as long as a school bus and weigh over half a ton! Watch this short video to see an amazing diversity of mollusks: . MEDIA Click image to the left or use the URL below. URL: Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. Mollusks reproduce sexually. Most species have separate male and female sexes. Fertilization may be internal or external, depending on the species. Fertilized eggs develop into larvae. There may be one or more larval stages. Each one is different from the adult stage. Mollusks live in most terrestrial, freshwater, and marine habitats. However, the majority of species live in the ocean. They can be found in both shallow and deep water and from tropical to polar latitudes. They have a variety of ways of getting food. Some are free-living heterotrophs. Others are internal parasites. Mollusks are also eaten by many other organisms, including humans. Annelids are segmented worms in Phylum Annelida. There are about 15,000 species of annelids. They range in length from less than a millimeter to more than 3 meters. To learn more about the amazing diversity and adaptations of annelids, watch this excellent video: [Link] MEDIA Click image to the left or use the URL below. URL: Annelids are divided into many repeating segments. The earthworm in Figure 12.18 is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be specialized to carry out particular functions. They may have special structures on them. For example, they might have tentacles for sensing or feeding, paddles for swimming, or suckers for clinging to surfaces. Annelids have a large coelom. They also have several organ systems. These include a: circulatory system; excretory system; complete digestive system; and nervous system, with a brain and sensory organs. Most annelids can reproduce both asexually and sexually. Asexual reproduction may occur by budding or fission. Sexual reproduction varies by species. Some species go through a larval stage before developing into adults. Other species grow to adult size without going through a larval stage. Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of
[EX A]: All of the following are annelids except

[EX Q]: Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder resulting in the growth of a variety of tumours, and is inherited in an autosomal dominant pattern. Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours that commonly harbour oncogenic mutations in KIT or PDGFRA and are thought to arise from the interstitial cells of Cajal (ICC; the pacemaker cells of the gut). To characterise two patients with NF1 and GISTs. Two patients were genotyped for germline mutations in NF1. GISTs from both patients were genotyped for somatic mutations in KIT and PDGFRA. Loss of heterozygosity (LOH) of NF1 in one GIST was assessed by genotyping seven microsatellite markers spanning 2.39 Mb of the NF1 locus in the tumour and in genomic DNA. The known germline mutation in NF1 was confirmed in GIST DNA by sequencing. The copy number of the mutated NF1 allele was determined by multiplex ligand-dependent probe amplification. GISTs from both patients were of wild type for mutations in KIT and PDGFRA. In the GIST with adequate DNA, all seven markers were informative and showed LOH at the NF1 locus; sequencing of NF1 from that GIST showed no wild-type sequence, suggesting that it was lost in the tumour. Multiplex ligand-dependent probe amplification analysis showed that two copies of all NF1 exons were present. This is the first evidence of mitotic recombination resulting in a reduction to homozygosity of a germline NF1 mutation in an NF1-associated GIST. We hypothesise that the LOH of NF1 and lack of KIT and PDGFRA mutations are evidence of an alternative pathogenesis in NF1-associated GISTs.
[EX A]:
Which is the gene mutated in type 1 neurofibromatosis?