Problem: Plants synthesize a number of unique polymers like the polysaccharide molecules cellulose, pectin and xyloglucan from which the land plant cell wall is constructed. Vascular land plants make lignin, a polymer used to strengthen the secondary cell walls of xylem tracheids and vessels to keep them from collapsing when a plant sucks water through them under water stress. Lignin is also used in other cell types like sclerenchyma fibers that provide structural support for a plant and is a major constituent of wood. Sporopollenin is a chemically resistant polymer found in the outer cell walls of spores and pollen of land plants responsible for the survival of early land plant spores and the pollen of seed plants in the fossil record. It is widely regarded as a marker for the start of land plant evolution during the Ordovician period. The concentration of carbon dioxide in the atmosphere today is much lower than it was when plants emerged onto land during the Ordovician and Silurian periods. Many monocots like maize and the pineapple and some dicots like the Asteraceae have since independently evolved pathways like Crassulacean acid metabolism and the C4 carbon fixation pathway for photosynthesis which avoid the losses resulting from photorespiration in the more common C3 carbon fixation pathway. These biochemical strategies are unique to land plants.
What weakens cell walls?
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Answer: water stress


Problem: Southampton's police service is provided by Hampshire Constabulary. The main base of the Southampton operation is a new, eight storey purpose-built building which cost £30 million to construct. The building, located on Southern Road, opened in 2011 and is near to Southampton Central railway station. Previously, the central Southampton operation was located within the west wing of the Civic Centre, however the ageing facilities and the plans of constructing a new museum in the old police station and magistrates court necessitated the move. There are additional police stations at Portswood, Banister Park, Bitterne, and Shirley as well as a British Transport Police station at Southampton Central railway station.
On what street in Southampton is the police headquarters for the city?
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Answer: Southern Road


Problem: The event of the Protestant Reformation and the politics that ensued has been cited as the origins of German identity that arose in response to the spread of a common German language and literature. Early German national culture was developed through literary and religious figures including Martin Luther, Johann Wolfgang von Goethe and Friedrich Schiller. The concept of a German nation was developed by German philosopher Johann Gottfried Herder. The popularity of German identity arose in the aftermath of the French Revolution.
Who was Johann Herder?
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Answer:
German philosopher