Answer:
Natural selection is one of the mechanisms by which an organism evolve. In the natural selection when the trait of an organism allows the organism to grow and reproduce in an environment and nature selects it, it is then passed on to the generations and become permanent.
Artificial selection is also one of the mechanism of evolution in which instead of nature, the selection is made by humans like the breeding experiments on dogs and plant crops.
The artificial selection and natural selection are interlinked as in the artificial selection the trait selected by the humans were also selected by nature like the case of crops, the crossing between desired plants produced results which were useful to the humans but grew and reproduced only when the environment selected it to grow and reproduce.
 
        
             
        
        
        
Answer:
When water is added to a graduated cylinder, having a surface where the sides of the water look higher than the center means that the curved surface is a concave meniscus which has formed because of surface tension (Choice C).
Explanation:
A meniscus is simply the curvature that the surface of a liquid acquires when it is in a container, such as a graduated cylinder. It is concave when there is attraction between molecules -water and glass- or it can be convex when both surfaces are repelled.
<u>Water is a polar molecule</u>, with the capacity to adhere to the surfaces it comes into contact with. This characteristic causes it to form a concave meniscus, as the outermost molecules adhere to the glass surface, while the surface tension of the water attracts the molecules from the centre downwards, causing the concavity.
Learn more:
Measuring with a graduated cylinder brainly.com/question/4070509
 
        
                    
             
        
        
        
A. Abrasion
Reason - cause by scraps on rough surface which breaks skin on outer layer.
        
                    
             
        
        
        
The term for blue skin caused by lack of oxygen is cyanosis. One is said to be cyanotic when presenting with this discoloration.