Asample of rock is found to contain 100 grams of a parent isotope. how many grams of the parent isotope will remain after two half-lives?

100

75

50

25

Membrane vesicles containing an internal sodium chloride (nacl) concentration of 0.14 m are placed into separate beakers each containing a different solution. the first beaker contains 0.14 m sucrose, while the second beaker contains 0.14 m calcium chloride (cacl2). the temperature is 25°c. what is the solute potential inside the vesicles, expressed in units of mpa?

Has magnification ability of hundreds of thousands of times

According to the rna world hypothesis, rna acted as the genetic material and catalyzed reactions in ancient cells. what conclusion can you draw from this?               a.  this implies that dna and proteins aren't essential in cells today.    b.  this implies that rna can catalyze any chemical reaction that enzymes catalyze.    c.  this implies that if a cell has a problem with its dna, its rna can compensate for the damaged dna.    d.  this implies that dna and proteins evolved after rna.