Think about the fact that water is most dense at 4°C, and the fact that ice is much less dense than water.
a. What would happen to a lake or a pond in the winter in a cold climate) if this wasn't the
case?
B. what would happen if the water continued to contract, and the solid form (ice) was more dense than liquid water

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

you need more balloons

if someone had the list of traits you provided