Three reasons why dichotomous keys would be subject to changes over time

The dichotomous key refers to a tool that determines the unfamiliar organism by comparing its features with the arranged set of mutually exclusive features of distinct species. The dichotomous keys modify with time due to the following reasons:  

1. The keys are framed on the basis of the features of the previously known organisms. If one finds novel features in the newly invented organisms, the keys get modify.  

2. The organisms can modify their features because of evolution.  

3. The dichotomous keys are totally dependent upon history. The scientists may not witness the present evolutionary variations taking place. This signifies that this characteristic will be determined later in the coming time, therefore, the keys modify.  

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.