Please answer 2 out of the 3 questions below. If you wish, y…

Pleаse аnswer 2 оut оf the 3 questiоns below. If you wish, you mаy answer all 3 questions. We will then grade all three questions, and give you the sum of your grades for all of them. Thus you can receive up to 30/20 points for these short answer questions. Be sure to use the number of the question to identify each of your answers.   1) (10 points): i) What is the definition of a biosignature? There are two necessary parts to the definition. ii) Briefly describe two examples of biosignatures (or technosignatures) by which we might search for life on exoplanets. For each, include why it may be evidence for life.   2) (10 points): In class, we discussed three different types of fossils that we might look for in the rock record as evidence of life. Name and define each of these types, and provide an example of each that you might expect to find on Earth.   3) (10 points): Why does the “universal tree of life” suggest that the earliest forms of cellular life on Earth were thermophilic or hyperthermophilic?