Sap transport proteins. Recent evidence indicates that mobile proteins and RNA are part of the plant's long-distance communication signaling system. Evidence also exists for the directed transport and sorting of macromolecules as they pass through plasmodesmata." A large number of insects of the order Hemiptera (the half-wings), feed directly on phloem sap, and make it the primary component of their diet. Phloem sap is "nutrient-rich compared with many other plant products and generally lacking in toxins and feeding deterrents, [yet] it is consumed as the dominant or sole diet by a very restricted range of animals". This apparent paradox is explained
Sugary drink tax sugary drinks that will be sold. Whether the sugary drinks tax is imposed on the seller or consumer, in both cases the tax burden is shared between both. The way that the tax burden is divided upon the consumer and seller depends on the price elasticity for sugary drinks. The tax burden will fall more on sellers when the price elasticity of demand is greater than the price elasticity of supply while on buyers when the price elasticity of supply is greater than the price elasticity of demand. The price elasticity for sugary drinks is different from country to country.