A is the correct answer I belive
<span>The plant cell was placed in a hypertonic solution. Due to its higher concentration of solutes and a net movement of water outside a hypertonic solution causes the cell to shrink. In other words, when a plant cell is placed in hypertonic solution the water from the cell will be forced out of the cell in an attempt to balance itself. This is known as plasmolysis.</span>
The reasons are:
- the blood is very low on nutrition
- the leech is not feeding itself regularly
The leech slows it metabolism a lot, so it can survive on very low nutrition. The blood is very low on nutrition, and it is the leech's food source, so the evolution made it preserve energy.
The leach doesn't have the opportunity to feed itself on regular basis, so it takes maximum advantage of any opportunity and consumes as much blood as possible so that it can survive long term when it will not have food at disposal.
you need the organisms in order to get help on this
Answer:
E. have a variable region that binds to a specific antigenic determinant.