An E. coli cell whose DNA contains N¹⁴ is placed in media with dNTPs containing a heavy isotope of nitrogen, N¹⁵,which incorporates into newly synthesized DNA. After one cell division, what will the DNA in the daughter cells look like?
A) One cell will have both strands of the helix N14; the other cell will have both strands of the helix N15.
B) One cell will have mostly N14 with a little bit of N15; the other cell will have mostly N15 with a little N14.
C) Each cell will have one strand of N14 and one strand of N15.
D) It is impossible to predict what the DNA in the daughter cells will look like.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.