Yes, Jan should undergo genetic sequencing.BRCA1/BRCA2 are the causes of 20-25% of all hereditary breast cancers, so if Jan's mother and sister both have breast cancer, then the odds are that she has BRCA1 as well.
The answer is either A or B
a. RNA molecules is the correct answer.
Hope this helps~
The first living things on Earth, single-celled micro-organisms or microbes lacking a cell nucleus or cell membrane known as prokaryotes, seem to have first appeared on Earth almost four billion years ago, just a few hundred million years after the formation of the Earth itself.
