<span>Tap water is one of the three test conditions of the independent variable, the type of water.</span>
Ostrich eggshell is composed of 96% crystalline calcite and 4% organic material, mostly proteins. The thickness is made up of three different layers that vary in structure and thickness. The hardness of the shell is 3 on the Mohs scale. Pretty solid!
<h2>
Answer:</h2>
The scientist started to study relationships among various groups of organisms <u>C. by using genetic analyses</u>.
<h2>
Explanation:</h2>
The following features were used to study about the relationships between different groups of organism:
- External morphology
- Similarities in structure
- Genetic analysis
- Chemical composition
The molecular similarities in the structure of RNA, DNA, and proteins help to establish the relationship of relationships between different groups of organisms. This was studied through testing the samples obtained by organisms using genetic analyses.