When all plant structures have a set of chromosomes, it is called the gametophyte stage.?

Which is not a characteristic of the animal kingdom? a. they include both vertebrates and invertebrates b. their skin is covered with hair or fur c. they are heterotrophs d. they are eukaryotic

Explain why process 2 is so important to sexual reproduction identify processes 1 and 3 state one difference between the cells produced by process 1 and cells produced by process 3

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?