How to form an hypothesis on the effects of ph on enzymes?

Arrange the following in the correct sequence, from earliest to most recent, in which these plant traits originated. 1. sporophyte dominance, gametophyte independence 2. sporophyte dominance, gametophyte dependence 3. gametophyte dominance, sporophyte dependence a) 1 → 2 → 3 b) 2 → 3 → 1 c) 2 → 1 → 3 d) 3 → 2 → 1 e) 3 → 1 → 2

What are two ways that harvesting algae from the ocean may benefit human society? how might the harvest of algae negatively impact the ocean communities where that algae grows? how could this be prevented?

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?