Early earth quiz which of the following gases was most likely present in earth’s earliest atmosphere? a. nitrogen. b. hydrogen. c. argon. d. oxygen.

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Maria wanted to grow a fern in her backyard. acting on a suggestion from a friend, she collected brown dots from the underside of a fern's leaves and then potted them. after a few days, maria saw small fern leaves erupting from the pot. which statement explains this phenomenon? a. the fern transitioned from gametophyte generation to sporophyte generation. b. the fern grew as a result of mitosis. c. the fern transitioned from sporophyte generation to gametophyte generation. d. the fern grew to be genetically identical to its parent plant.

Which statement about inheritance is true? o girls get most of their traits from their moms, boys get most of their traits from their dads. o male offspring will always have an x-linked genetic disease if the mom is a carrier o fathers always determine the gender of the offspring in humans. o males never have y chromosomes.