What was thomas hunt morgan's main contribution to science? he discovered that certain traits were linked to the x chromosome. he discovered that certain traits were linked to the y chromosome. he created the first white-eyed female drosophila. he created the first white-eyed male drosophila.

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?