Answer:
To observe the cheek cell,
- 
Take a tooth pick use its blunt side to scrap inside the mouth.
- You will see some deposition on the blunt side of tooth pick, make a smear on the clean slide in the center using that tooth pick.
- Add a drop of methylene blue solution and place a coverslip, make sure that bubbles are avoided i.e. coverslip should be placed in the inclined manner.  
- Remove the excess solution and observe it under the microscope first under 4X and then under 10X. 
Observation:  
- The cells observed are squamous epithelial cells. The small blue dots seen inside will be the bacteria from our teeth and mouth.
 
        
             
        
        
        
2 The correct answer is (b)beach erosion to the unprotected coastline
A large storm destroys the greenbelt of an island  The consequences is beach erosion to the unprotected coastline. The beach erosion takes place in the area which is not protected.
3 The correct answer is (b) a loss of biodiversity due to human activity
The forest habitat is cleared which results in the loss of biodiversity by human interventions. The area which was the habitat of organisms has now been converted into shopping complex due to which the habitat loss of many organisms took place.
 
        
                    
             
        
        
        
Answer: They are all formed from the same elements.
 
        
             
        
        
        
Answer:
B
Explanation:
CRISPR-Cas9 is a gene-editing mechanism that is harnessed from bacteria’s immune system used to cut apart foreign genetic material such as that of bacteriophages. CRISPR-Ca9 has a guide sequence that is used to identify the target sequence. The Cas9 enzyme cuts this target DNA and is replaced with the required piece.
In cancer treatment, the mutated DNA can be replaced, this way, with the wild type.