Idon't understand this!
nucleotide substitutions occur by mistake in a segment of ribosomal rna at a constant rate of one substitution every 10,000 years. a biologist has compared the ribosomal rna of two modern0day species and found that they have six differences in their sequences. how many years ago did these species diverge from a common ancestor? (2 points)
select one:
a. 3,000 years ago
b. 60,000 years ago
c. 30,000 years ago
d. 6,000 years ago

Why do carbohydrate molecules function so well as fuel for the body?

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates