Stromatolite fossils are the oldest known fossils<span>, that formed 3.5 billion years ago when the environments of Earth were too hostile to support life as we know it today. They </span><span>are layered mounds, columns, and sheet-like sedimentary rocks</span><span>
Stromatolite fossils indicate that </span>life must have arisen quite a bit earlier, perhaps 3.9 billion years ago.
Answer:
Genetic variation is caused by:
mutation
random mating between organisms
random fertilization
crossing over (or recombination) between
chromatids of homologous chromosomes during
meiosis
Are their any choices for this or is this a written response?
I think it’s an African lily.
Answer:
may be D is the right answer because
electrons microscope it not easy to handle and so expensive but light microscope is easy to handle and less experience
