What do people mean when they are "double jointed" ?

Some plants rely on the wind to reproduce an example is it’s important for plants to use the forces of nature to reproduce because 1. 1a white tuft of dandelion seeds 2a spiked burrs surrounding seeds 3a hard shell on a walnut? 2. 1b require pollination to reproduce 2b reproduce only asexually 3b cannot move about freely?

What kind of seafood would you expect to have the highest levels of mercury and why? kelp, because they use the sun to photosynthesize on the bottom trophic level. oysters, because they filter feed on plankton on a lower trophic level. small fish, because they eat plankton on a higher trophic level. sharks, because they feed on organisms on a higher trophic level.

Describe the response the kidneys have to dehydration and excessive water intake. what happens to the concentration of urine in each case ?