Question

The human genome comprises just over 3.1 billion base pairs. 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?
a. 6.2 million
b. 124 million
c. 32 million
d. 3.1 milion
e. 62 million

Answer 1

Answer:

Option C, 32 million

Explanation:

As per standard rule -

Number of base pair per nucleosome is equal to $200$

Now, the total number of base pair in human genome is $3.1$ billion.

Number of nucleosome in $3.1$ billion base pairs is equal to

$\frac{3.1* 10^9}{200} \\= 1.55 * 10^ 7$

These are diploid cells and hence the number of nucleosomes will be 2n

Hence, the total number of nucleosomes are

$1.55 * 10^7 * 2\\3.1 * 10^7$

Hence, option C is correct