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.
Answer:
Three items that are unique to RNA are as follows:
2. Single-stranded.
3. Contains the nitrogen base Uracil in place of Thymine.
4. Backbone contains the sugar ribose.
Explanation:
Answer: 1.chromosomes, 2. Histones, 3. prokaryotes have one chromosome, 4. A sugar phosphate backbone with nitogen bases in the middle. 5. Chromatin
Explanation: Chromatin
Youngest to oldest would be: 3, 4, 1, 5, 2. Since it's from the bottom, the ones furthest from the bottom would be the youngest at the top. The oldest fossils would be closest to the bottom.
