The average human gene contains about 10% and 90% sequences
a. exon; intron
b. conserved; divergent
c. divergent; conserved
d. intron; exon
e. repetitive; unique

The correct answer is a. "exon; intron".

Explanation:

According to the article "Distributions of exons and introns in the human genome" published in the scientific journal "In silico biology", an average human gene have 8.8 exons and 7.8 introns. Regardless of having similar proportions, human exons and introns differ in their lenght. An average exon's length is about 170 bp, when the average intron's length is 5419 bp. Therefore, most of the genetic material is comprised of introns (90%), while only a small part is comprised of exons (10%).

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.

multiplying and dividing the two decimals and the eqations by the same number of the overalls