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

Robert wants to know which fertilizer will work the best for his grass. what can he do to explore this inquiry?

Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. he used a golf ball, a tennis ball, and a soccer ball. he dropped each ball from the balcony once. diego recorded his observations after each drop. what can diego do to best improve the reliability of his results? a) drop each ball from the platform three more times b) record his observations in more than one unit c) write at least two scientific questions after the experiment is complete d) share his results with other people who have done similar experiments you for the !

You want to cultivate some exotic plants at your farm. however, the climate is chillier than the temperature range favorable to the crop. which is the best method to use for the cultivation of this exotic crop? a. use a crop rotation method b. use a lot of fertilizer c. prepare the seed bed properly d. use a greenhouse e. use irrigation