Assuming average nucleosome spacing throughout the genome, how many molecules of histone h2a are present in the chromatin of one somatic human cell after dna replication but before cell division?

Two molecules of H2A

Explanation:

Structural organization of nucleosomes were determined by isolating them from unfolded chromatin and it has been found that the basic units of chromatin are the nucleosomes which consist of histone octamers of two molecule each of histone H2A and other histone molecules like H2B, H3 and H4. The histones are wrapped around with 147bp of DNA in almost two (2) turns.

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.