1. In the 1950s when Watson and Crick were working on their model of DNA, many scientists did not think that DNA carried the genetic code. What was the other type of molecule that some scientists thought might carry genetic information? *

Proteins

Explanation:

Since proteins were made up of 20 different types of amino acids and DNA was only four A,G,C and T many scientists thought that these were most likely to be carrying information. In addition to amino acids being in so many varieties they were also of different charges and shapes as well. It was believed that the amount of information that can be held in these 20 amino acids are much greater than that that can be held in just four bases.

explanation:

b,bacteria convert nitrates

into nitrogen gas.

d,plants and animals take in

and use nitrogen compounds.

e,bacteria break down waste    

products and return nitrogen  

to the soil.

a,bacteria convert atmospheric

nitrogen to ammonia.

c,bacteria convert ammonia

to nitrites and nitrates.