A dichotomous key helps you identify unknown specimens based on their traits because there are only two options available per trait. Selecting one from the two options (usually contrasting characteristics) from each step leads to smaller and smaller groups until the option is reduced to single and unique trait of an organism.
Considering you need to identify an organism. So, on the top of they key is animal with options: (a) with red blood cells and (b) no red blood cells. The option you will select is no red blood cells and under option b, you’re given two choices again: (a) hard bodies and (b) soft bodies. You’ll select soft bodies, then two options again are given: (a) with shell and (b) without shell. The option you’ll select would be without shell, and so on.
The atmosphere
Is not a reservoir for phosphorus.
Answer:
A single gene form different isoforms of protein that result from the alternative splicing of pre-mRNA sequences. one gene many polypeptide hypothesis applies here very well. This whole process helps in proliferating informational diversity and functional capacity of a gene that'll ultimately he;p in gene regulation.
This alternative splicing of pre-mRNA also produces proteomic diversity that result in various development states as well as various disease conditions later.