Discuss what properties of water protect organisms that live underwater.
As a 4th year student, I am assuming that you will require a very in-depth response to this problem. All the same, in order to help you better understand (and answer) this question, I think it is best to pick out the terms in this question and discuss them separately and then relate them to each other. Although it may seem simplistic, this approach should give you a strong foundation for a very thorough answer.
I would therefore start by defining 'organisms' keeping in mind that there are certain features required to be classified as an organism (such as growth and reproduction) and that organisms may range in complexity from a single-celled life form to complex animals. As you have noted that the topic is bacteria and ...
This solution highlights points to consider regarding the various properties of water and in what ways these may be protective to the organisms that live within this ecosystem, being sure to consider the range and diversity of environmental conditions that may be present underwater.