Answer should be Achilles tendon
Brainless beck has no idea of what us has to say when the game
<span>Red blood cells normally have a biconcave shape (picture a donut, but instead of a hole through the centre there's just a downward slope to the centre of the cell). If the cell takes on water, it will increase in size and the sloped areas will start to flatten out. If the cell loses water, it will begin to shrivel. Use these observations and your understanding of osmosis to answer the question!</span>
Assuming this is multiple choice, the answer would be "niche". An organism's niche is where that certain organism fits into an ecosystem, or what their part to play is.