Specimens taken from a patient sample usually contain a mixture of different bacteria. But sample with only one type of bacteria, are necessary to study a bacterial species accurately. Therefore, it is necessary to isolate all of the possible disease causing organisms in order to study the sample by itself. Once isolation of individual colonies is done, then these colonies can be used for identification tests. A sample of the specimen is move very fast onto an agar plate in order to physically separate the bacterial colonies.
 
        
                    
             
        
        
        
1. Answer; 
-secondary structure; 
Explanation; 
Protein secondary structure refers to regular, repeated patterns of folding of the protein backbone. The two most common folding patterns are the alpha helix and the beta sheet. In an alpha helix, the polypeptide backbone coils around an imaginary helix axis in clockwise direction. In the beta sheet secondary structure, the polypeptide backbone is nearly fully extended. The R-groups are alternately pointed above and then below the extended backbone.
2. Answer;
- Quaternary structure 
Explanation;
-Many proteins are formed from more than one polypeptide chain. The Quaternary structure describes the way in which the different subunits are packed together to form the overall structure of the protein. For example, the human hemoglobin molecule shown below is made of four subunits.
3. Answer;
-Tertiary structure 
Explanation;
Tertiary structure refers to the overall folding of the entire polypeptide chain into a specific 3D shape. The tertiary structure of enzymes is often a compact, globular shape.
The tertiary structure is the structure at which polypeptide chains become functional. At this level, every protein has a specific three-dimensional shape and presents functional groups on its outer surface, allowing it to interact with other molecules, and giving it its unique function.
4. Answer;
Primary structure
Explanation; 
-It is the simplest level of protein structure and is simply a sequence of amino acids in a polypeptide chain. For example, the hormone insulin has two polypeptide chains, A and B. Each chain has its own set of amino acids, assembled in a particular order. For instance, the sequence of the A chain starts with glycine at the N-terminus and ends with asparagine at the C-terminus, and is different from the sequence of the B chain. 
 
        
             
        
        
        
Answer:
You are correct it's the earth! 
Explanation:
The reason why is because, the term "elliptical orbit" is used in astrophysics and astronomy to describe an oval-shaped path of a celestial body. The Earth, as well as all the other planets in the Solar System, follow this type of orbit around the Sun. The shape is created by the varying pull of forces, such as gravity, on two objects, such as the Sun and a planet.
Hope this helps! :)