How long ago did oceans begin to form?
12.5 MYA
137 MYA
285 MYA
3800 MYA

Study the image of this rock.which characteristic best supports its formation from sedimentary processes? it has many layers.it is coarse-grained.its grain shape is round.its texture is non-banded.

Aresearcher has developed two stains for use with seed plants. one stains sporophyte tissue blue; the other stains gametophyte tissue red. if the researcher exposes pollen grains to both stains, and then rinses away the excess stain, what should occur? a) the pollen grains will be pure red.b) the pollen grains will be pure blue.c) the pollen grains will have red interiors and blue exteriors.d) the pollen grains will have blue interiors and red exteriors.

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!